AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Copyright 2006, Renesas Technology Corp. All rights reserved. AE45X1-C (HD65145X1) Version 02 Smartcard Security Target - Public Version - Renesas Technology Corp. Revision 3.0 11 July, 2006 AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page ii Revision Revision Date Section Description Rev. 1.0 16 Mar., 2006 — Release 0.4, 1.2 Updated information of [UGM]. Rev. 2.0 15 June, 2006 1.1 Updated the version of base full-ST. 1.1 Updated the version of base full-ST. Rev. 3.0 11 July, 2006 4.1.1 Modified descriptions of O.Phys-Probing and O.Phys-Manipulation. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page iii 0 Preface 0.1 Objectives of Document This document defines the Security Target for evaluation of the Renesas AE45X1-C. Although no evaluated conformance claim is made, it is intended to conform as far as possible with the requirements of the IC package of the SCSUG Protection Profile, and to provide support for operating system and application software that aims to meet SCSUG requirements. 0.2 Scope of Document This document defines the Security Target as required by [CC/1]. This is a Public version of the document used in the evaluation process. 0.3 Intended Readership Developers concerned with certification of the TOE. Developers of Smartcard Embedded Software to run on the TOE. Evaluators and certifiers of the TOE. 0.4 Related Documents A reference of the form [REF, n] refers to section n of REF. Literature [BSI-PP-0002] Smartcard IC Platform Protection Profile, v1.0, Eurosmart, July 2001 [AIS31] Functionality classes and evaluation methodology for physical random number generators, AIS 31, v3.1 (part of Bundesamt für Sicherheit in der Informationstechnik Application Notes and Interpretation of the Scheme), Certification Body of the BSI [CC/1] ISO/IEC 15408-1:1999 (E) Information Technology – Security techniques – Evaluation criteria for IT security – Part 1: Introduction and general model, 1999-12-01 [CC/2] ISO/IEC 15408-2:1999 (E) Information Technology – Security techniques – Evaluation criteria for IT security – Part 2: Security functional requirements, 1999-12-01 [CC/3] ISO/IEC 15408-3:1999 (E) Information Technology – Security techniques – Evaluation criteria for IT security – Part 3: Security assurance requirements, 1999-12-01 Note: the combination of all 3 parts of ISO 15408 is also referred to in this document as "Common Criteria" or "CC". [PA] Smartcard Integrated Circuit Platform Augmentations, v1.0, Atmel, Hitachi Europe, Infineon Technologies & Philips Semiconductors, March 2002 Documents and User Guidance [CCF] AE45X1-B/C (HD65145X1) Current Control Functions, Rev. 1.0, Renesas Technology Corp., 11 June 2004 [HM] AE45X1 Hardware Manual, Rev. 3.1, Renesas Technology Corp., 15 November 2004 [OPT] Option List for Smart Card Microcomputer (for HD65145X1 [AE45X1-C]), v.1.5, Renesas Technology Corp., 6 February, 2006 [PM] Hitachi Single-Chip Microcomputer H8SX Programming Manual, Revision 1.0, Hitachi Ltd., February 2003 AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page iv [UGM] AE45X1 User Guidance Manual, Rev. 7.20, Renesas Technology Corp., 18 April 2006 0.5 Document Structure This document follows the structure set out in [CC/1]. Note that sub-sections are structured to show parts that originate from [BSI-PP-0002], [PA] and other sources. 0.6 Outstanding Issues None. 0.7 Glossary Term Meaning CBC Cipher Block Chaining A mode of DES encryption. CC Common Criteria (ISO 15408) COT Chip-on-Tape ― an IC packaged in a form suitable for embedding into a plastic card to form a smart card. CPU Central Processing Unit CRAM RAM dedicated for use by MMC DES Data Encryption Standard DFA Differential Fault Analysis DPA Differential Power Analysis EAL Evaluation Assurance Level ECB Electronic Code Book A mode of DES encryption. EEPROM Electronically Erasable Programmable Read-Only Memory Embedded Software Software held in the chip, having been developed by users of the TOE. Such software generally includes an operating system and may include all or part of applications. There are two types of Embedded Software: Hard-coded – held in ROM Soft-coded – held in EEPROM or RAM. The chip does not depend on such software, and the Embedded Software is not part of the TOE. However, hard-coded Embedded Software will be included in the ROM of any issued TOE at manufacturing time. Note that Embedded Software includes all software on a chip other than the IC Dedicated Software. Embedded Software is also referred to as ‘Smartcard Embedded Software’ (especially in [BSI-PP-0002]). EWE An interrupt generated by the TOE whenever an attempt is made to write to EEPROM. FMU Firewall Management Unit – a feature of the TOE that limits the memory areas available. HW RNG Hardware random number generator (physical random number generator) IC Integrated Circuit IC Dedicated Software Software developed by Renesas and embedded in the IC. (Adopted from [BSP-PP-0002]) IC Dedicated Test Software Software developed by Renesas for testing the TOE during manufacture. This software is part of the TOE, but is not available for general use by operating systems, applications or end-users in phase 7 of the lifecycle (see section 2.3). ISC Integrated Security Concept IT Information Technology LSI Large Scale Integration Manufacturing Identification Data Some basic data injected into EEPROM, enabling traceability of an IC to the lot and line in which it was manufactured, the Smartcard Embedded Software present, and the versions of masks and specifications applicable. MCU Micro Computer Unit MMC Modular Multiplication Coprocessor AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page v Term Meaning Option List A form supplied by Renesas and filled in by a TOE customer, specifying various options for the manufacture of TOE ICs for that customer. The aspect of particular interest to this security target is : Selection of whether pre-personalisation data injection is required The option list also describes the content and structure of the manufacturing identification data that Renesas will inject (see section 2.4.2). PKI Public Key Infrastructure PP Protection Profile RAM Random Access Memory Renesas Refer to Renesas Technology Corp. (http://www.renesas.com/) Reset state A state in which the chip does not execute instructions or engage in input/output. The chip can exit the reset state by receiving an external reset. See also section 6.1. RNG Random number generator ROM Read-Only Memory RSA Rivest, Shamir, Adelmann – a public key encryption algorithm, named after its inventors. SFP Security Function Policy SFR Security Functional Requirement Smartcard (as used in [BSI-PP-0002]) Composition of the TOE, the Smartcard Embedded Software, User Data and the package (the smartcard carrier). SOF Strength of Function ST Security Target TOE Target of Evaluation. TOE consists of the chip (IC) and other materials and data. However, the term is sometimes used to indicate just the chip. TOE Delivery The point at which the TOE is delivered, as shown in section 2.3. This may be either in the form of wafers (at the end of phase 3) or as packaged modules (at the end of phase 4). TOE Manufacturer (As defined in section 8.7 of [BSI-PP-0002]) The IC developer and manufacturer. If the TOE is delivered after phase 4 (i.e. as packaged modules, rather than wafers) then this is also the packager. For the AE45X1-C, the TOE Manufacturer refers to Renesas. TSC TSF Scope of Control TSF TOE Security Functions TSF Data Data created by and for the TOE and that might affect the operation of the TOE. Type-C FeliCa contactless transmission protocol. The TOE has an RF interface to support the communication compliant with Type-C. UART Universal Asynchronous Receiver Transmitter – in accordance with ISO/IEC7816-3. UMTS Universal Mobile Telecommunications System. Third generation wireless standard. User Data All data managed by the Smartcard Embedded Software in the application context. User data comprises all data in the final smartcard IC except for the TSF data. User Mode The mode of operation after TOE Delivery. The TOE is set to this mode just before delivery, which renders the IC Dedicated Test Software permanently unavailable. USIM Universal Subscriber Identity Module (Universal SIM). An application upgraded from the SIM, which is used for GSM (Global System for Mobile communications). WAP Wireless Application Protocol WDT Watchdog Timer – a feature of the chip that enables embedded software to be regularly executed during the operation of the IC. This allows checks to be made on the execution environment to help detect potential attacks or insecure conditions. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page vi Table of Contents 1. ST Introduction ...............................................................................................................1 1.1 ST Identification ..................................................................................................1 1.2 TOE Identification ...............................................................................................1 1.3 ST Overview........................................................................................................2 1.4 CC Conformance Claim.......................................................................................3 2. TOE Description .............................................................................................................4 2.1 AE45X1-C Product Description...........................................................................4 2.1.1 Hardware..................................................................................................4 2.1.2 Software...................................................................................................6 2.1.3 Documents ...............................................................................................7 2.2 TOE Intended Usage............................................................................................7 2.3 TOE Lifecycle .....................................................................................................7 2.3.1 Test and User Modes..............................................................................10 2.3.2 TOE Delivery.........................................................................................10 2.4 TOE Environments ............................................................................................10 2.4.1 Development Environment.....................................................................10 2.4.2 Injection of Manufacturing Identification and Secret Data......................11 3. TOE Security Environment............................................................................................12 3.1 Assets ................................................................................................................12 3.2 Assumptions ......................................................................................................13 3.2.1 Assumptions from [BSI-PP-0002] ..........................................................13 3.2.2 Assumptions from [PA]..........................................................................14 3.2.3 Other Assumptions.................................................................................14 3.3 Threats...............................................................................................................14 3.3.1 Threats Defined in [BSI-PP-0002]..........................................................14 3.3.2 Other Threats..........................................................................................17 3.4 Organisational Security Policies.........................................................................18 3.4.1 Policy Requirement from [BSI-PP-0002]................................................18 3.4.2 Policy Requirement from [PA] ...............................................................19 4. Security Objectives........................................................................................................21 4.1 TOE Security Objectives....................................................................................21 4.1.1 Objectives from [BSI-PP-0002]..............................................................21 4.1.2 Objectives Based on [PA].......................................................................23 4.1.3 Other Objectives.....................................................................................24 4.2 Environment Security Objectives .......................................................................25 4.2.1 Environment Security Objectives from [BSI-PP-0002]...........................25 4.2.2 Other Environment Security Objectives..................................................26 5. IT Security Requirements ..............................................................................................28 5.1 TOE Security Requirements...............................................................................28 5.1.1 TOE Security Functional Requirements from [BSI-PP-0002] .................29 5.1.2 TOE Security Functional Requirements Based on [PA] ..........................34 5.1.3 Other TOE Security Functional Requirements........................................35 5.1.4 TOE Security Assurance Requirements ..................................................37 5.2 Security Requirements for the Environment.......................................................37 5.2.1 Security Requirements for the IT Environment from [PA]......................37 5.2.2 Security Requirements for the Non-IT Environment...............................39 AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page vii 6. TOE Summary Specification .........................................................................................41 6.1 TOE Security Functions.....................................................................................41 6.2 Correspondence Between TOE Security Function and SFR................................45 6.3 Assurance Measures...........................................................................................45 7. PP Claims......................................................................................................................47 7.1 PP Reference......................................................................................................47 7.2 PP Tailoring .......................................................................................................47 7.3 PP Additions ......................................................................................................47 8. Rationale .......................................................................................................................48 8.1 Security Objectives Rationale ............................................................................48 8.2 Security Requirements Rationale .......................................................................50 8.2.1 Dependencies .........................................................................................53 8.3 TOE Summary Specification Rationale..............................................................55 8.4 Assurance Requirements and Strength of Function Rationale.............................56 8.5 Mutual Support and Internal Consistency...........................................................56 8.6 PP Claims Rationale...........................................................................................56 AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page viii AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 1 of 56 1. ST Introduction The ST aims to provide potential users of the TOE with A definition of the main properties of the IC that are evaluated and certified independent of any software Confidence in IC properties that can be used to build an integrated TOE (i.e. IC + operating system + other application software). 1.1 ST Identification Title: AE45X1-C (HD65145X1) Version 02 Smartcard Security Target – Public Version Revision: 3.0 Provided by: Renesas Technology Corp. This Security Target applies to the Renesas AE45X1-C integrated circuit (version 02) (as defined in detail in the configuration list for the evaluation). This public version of the AE45X1-C Security Target (also known as “ST-lite”) is abridged from the evaluated version of the full Security Target (revision 9.0) with the approval of the Certification Body. 1.2 TOE Identification The TOE configuration is summarised in the table below: Table 1-1: TOE Configuration Item Type Item Version Form of delivery Hardware AE45X1-C (HD65145X1) smartcard integrated circuit 02 Wafer or packaged module (see section 2.3) Software IC Dedicated Test Software Test ROM software 0.2 Included in AE45X1-C test ROM Document Hardware Manual 3.1 Hardcopy Document User Guidance 7.20 Hardcopy Document Option List 1.5 Electronic data/Hardcopy Document Current Control Functions 1.0 Hardcopy Further description of the TOE is provided in section 2.1. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 2 of 56 Chip IC Dedicated Test Software (implemented on hardware) Embedded Software (implemented on hardware) (out of the scope of TOE) Hardware Manual User Guidance ROM TOE Option List Current Control Functions Figure 1-1: Configuration of the TOE Figure 1-1 shows the configuration of the TOE. The TOE consists of hardware, software, and documents. The software (as part of the TOE) is provided as being implemented on the hardware. Among software, the Embedded Software developed by the TOE user is outside the scope of the TOE. 1.3 ST Overview This document is the ST for the Renesas AE45X1-C IC product, intended for use as a smart card IC. The TOE is ideally suited for security applications. Security has been built in from the start, forming an integral part of the whole Smartcard design concept. The whole development process (including secure chip design environment, secure production facilities and secure handling during shipment to the customer) is constantly reviewed in order to maximise the overall security package. The TOE can be delivered either in the form of wafers, or as packaged modules ready for embedding into a plastic card. Many security features such as integrated sensors, distributed layout, random number generation, DES engine and power analysis attack protection are all included providing an on-chip hardware security structure. Uniquely, Renesas smartcard devices are fabricated using a MONOS (Metal Oxide Nitride Oxide Silicon) EEPROM structure. MONOS advantages compared to standard EEPROM structures are resistance to radiation disturbance, high reliability and endurance. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 3 of 56 The TOE fulfils the requirements of Smart Card applications requiring large memory, high speed secure authentication, data encryption or electronic signature. Examples include: PKI, WAP, e- m-commerce, digital signature, USIM/UMTS, and credit card. Where public key is a core requirement, a high speed MMC able to process arithmetical data in a time frame that ensures a fast and free flowing application environment is required. The MMC ensures the performance required by today’s security applications. Applications such as WAP and e-m-commerce are ever expanding in scope and consequently the need for greater memory storage for both data and program code is ever increasing. The TOE provides a significant increase in ROM for program storage over previous devices whilst ensuring a balance of EEPROM for data storage. The move from single to multi-application on a single component is also rising due in part to new systems such as WAP and e-m-commerce. This requires not only additional memory for application data storage but also features such as FMU in order to provide data integrity between applications. 1.4 CC Conformance Claim This ST is compliant with [CC/1], [CC/2] and [CC/3]. The ST is [CC/2] extended and [CC/3] conformant. This ST includes assumptions, threats, objectives and SFRs defined in [BSI-PP-0002] and [PA]. The Assurance level is EAL4. The strength of function is SOF-basic. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 4 of 56 2. TOE Description 2.1 AE45X1-C Product Description The TOE consists of the hardware shown in Figure 2-1, along with IC Dedicated Test Software, some embedded software, and reference and guidance documents. IC Dedicated Test Software is used in IC production only, and is not available to users. As well as the functional interfaces, the IC surface is also considered as a TOE interface for some potential physical attacks, as described in section 3.3 of [BSI-PP-0002]. A block diagram of the chip is shown in Figure 2-1 below: DES coprocessor EEPROM RAM ROM I/O Port CPU System control logic Security logic Address Bus I/O-1/IRQ I/O-2/IRQ WDT (Optional) FMU Data Bus Modular multiplication coprocessor Interval timer 1 UART RNG Contactless Interface Interval timer 2 CRAM Input switch circuit CLK Vcc Vss LB LA RES Figure 2-1: Internal Block Diagram of the TOE 2.1.1 Hardware The TOE is an integrated circuit for smartcard based around the high-speed AE-4 Series CPU core (derived from Renesas’ widely used H8/300H general purpose core). As can be seen from the block diagram in Figure 2-1, the MCU comprises the following major blocks in addition to the CPU: ROM, RAM, EEPROM, random number generator (RNG), MMC, DES coprocessor, UART, two interval timers, WDT (optional), FMU, two I/O lines and contactless interface unit. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 5 of 56 CPU: the CPU can operate with either a 3V or 5V supply and a maximum internal clock frequency of 10MHz (at 3V) and is upwards compatible with the H8/300 core (as used in Renesas’ AE-3 series of smartcard ICs): The instruction set is implemented with 16-bit variable instruction lengths (2 to 10 bytes) and permits register to register arithmetic and logic operations. A linear address space of up to 16 Mbytes is possible. Signed or unsigned multiply instruction (8 x 8 or 16 x 16-bits) Signed or unsigned divide instruction (16 8 or 32 16-bits) Special EEPROM write instruction and high-speed block transfer instruction Memory: the TOE has a memory mapped architecture and allows the EEPROM to be used for both data and program storage. There is a special block of RAM dedicated for coprocessor use, that can be used as normal RAM when not required by the coprocessor. ROM: 144 kbytes (64 kbytes + 80 kbytes) RAM: 4 kbytes + 512 bytes of coprocessor RAM EEPROM: 36 kbytes o on-chip charge pump and independent oscillator o special write instruction, and interrupt generation on writing o page write/erase o individual page protection RNG: this can generate 16-bit random numbers. Using the RNG enables a unique value to be generated inside the chip, which improves the system security. MMC (Modular Multiplication Coprocessor): this unit consists of the control unit and the 512k bytes CRAM. The control unit is intended to form the basis for efficient implementations of asymmetric cryptography by providing high speed modular multiplication in hardware with a programmable data length from 160 – 1024 bits. As no cryptographic software or algorithm is provided by Renesas for the TOE, the functionality of this coprocessor is included in the evaluated hardware configuration, but its specific use in cryptographic software is not included. DES coprocessor: this hardware engine can be used to provide either DES or triple-DES functions to the users’ software with very little software overhead. Countermeasures against information leakage have been integrated into the coprocessor unit to make it resistant to such attacks with minimal software overheads or execution time penalties. These countermeasures are always active and make no additional requirements on Smartcard Embedded Software. Interval timer: the TOE has interval timer 1 and interval timer 2. These timers are identical and issue an interrupt at intervals which user determined. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 6 of 56 WDT: the watchdog timer is a powerful tool to help the user software detect and respond to unauthorised program execution. Use of the WDT is optional and should be selected using [OPT]. FMU: this memory management function monitors memory access permissions for the user software and enables the limiting of program execution from RAM and EEPROM. UART: half-duplex asynchronous mode that conforms to the ISO/IEC standard 7816-3. Full- duplex asynchronous mode that conforms to the ISO/IEC CD standard 10536-4: I/O: I/O comprises I/O-1/IRQ and I/O-2/IRQ (see Figure 2-1). As well as the ISO 7816 standard I/O pin, a further I/O pin is provided for additional use. These pins, together with the power and clock pins, and the contactless RF interface, form the electrical interface of the TOE. Contactless interface: AE45X1-C is a dual-way type chip which has the RF interface (radio frequency power and signal interface) for contactless communication as well as the I/O pads for contact communication. The contactless interface consists of the control unit and 512 bytes contactless RAM, and offers one communication protocol: Type-C (FeliCa-Interface). Input switch circuit: The operation of the chip is determined either for contact communication or for contactless communication depending on to which interface (contact/contactless) the power is first supplied by the input switch circuit. Once determined, the operation is maintained until the power supply is stopped. System control logic: System control logic generates a signal to control the interface between the CPU subsystem and each other subsystem. Security logic: the IC incorporates specialised security logic to help to ensure the correct operation of the TOE. Some security features, such as FMU, allow the Smartcard Embedded Software to determine the events to be monitored and the actions to be taken; many of them however are independent of software and are designed to operate automatically when required, to return the TOE to a secure state. The IC also provides protection features to resist leakage attacks. Physical security of the IC is enhanced by the presence of shielding over critical areas, and by the use of design techniques that obscure the function and operation of the physical layout. Full details of the operation of the chip and guidance for its use are given in [HM], [CCF], [OPT], and [UGM]. 2.1.2 Software The TOE includes the following software: IC Dedicated Test Software: The IC Dedicated Test Software is integrated into the TOE hardware. It is used for mode transition and testing during IC production, and is not available to users. All other Smartcard Embedded Software (e.g. an operating system) is outside the scope of the TOE. The Smartcard Embedded Software is supplied to Renesas by the customer in a secure manner, and is then protected by Renesas’ secure production environment. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 7 of 56 2.1.3 Documents The TOE Hardware Manual [HM] is supplied as the basic reference for users who are developing Smartcard Embedded Software. Additional security features and their use are described in the Current Control Functions [CCF] document. Guidance for the secure use of the AE-4 Series in applications is given in the User Guidance Manual [UGM]. Options and contents of the identification data stored in the EEPROM are described in [OPT]. 2.2 TOE Intended Usage The TOE is intended for use in a range of security applications, including high speed secure authentication, data encryption or electronic signature. Examples include: PKI, WAP, m- commerce, digital signature, USIM/UMTS, and banking card. 2.3 TOE Lifecycle The design and manufacturing lifecycle for the TOE is shown in Figure 2-2 (and in section 8.1.1 of [BSI-PP-0002]). The TOE can be delivered either at the end of phase 3, or at the end of phase 4, as shown in the figure. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 8 of 56 Phase 6 Phase 5 Pre-personalisation requirements * Phase 3 Phase 4 Phase 2 IC Dedicated Software Phase 1 Pre-personalisation requirements Smartcard Embedded Software IC Design IC sensitive information, software, and tools Embedded Software Pre-personalisation data Alternative TOE Delivery points Smartcard IC Database Construction IC Photomask Fabrication IC Manufacturing IC Testing & Pre-personalisation IC Packaging Testing Smartcard Finishing Process Testing Testing Personalisation End of Life Process Smartcard Product End-Usage Phase 7 Legend: Optional component * Figure 2-2: Design and Manufacturing Lifecycle The stages shown are as listed below. This Security Target addresses phases 2 and 3 in Figure 2-2. When the TOE is delivered by Renesas as modules rather than in wafer form, phase 4 is also covered under this Security Target. Phase 1: Smartcard Embedded Software development – this phase is outside the scope of the TOE, but the results of the software development are inputs to the manufacture of a customer- specific instance of the TOE. Renesas deliver information about the TOE (such as [HM]) to the embedded software developer to enable the Smartcard Embedded Software to be written. Development tools (such as emulators) and IC samples are also available to developers. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 9 of 56 Information and tools are released only under Non-Disclosure Agreement to ensure their distribution is controlled and limited (this ensures, for example, secure disposal of scrap). The embedded software for incorporation in the ROM mask is sent via a secure delivery method from the software developer to Renesas, and its secure handling is then ensured by Renesas. Similarly, pre-personalisation data is sent by a secure route to Renesas for injection during the manufacturing stage. Injection of data is described further in section 2.4.2. Secure receipt and handling of this data by Renesas is included within the scope of this security target. Phase 2: IC design, IC Dedicated Test Software development – this includes system design through logic, circuit and layout design. The Dedicated Test Software is also developed in this phase, to enable testing of the IC at various phases of its manufacture. The Smartcard Embedded Software is received from phase 1. The security of the development environments for the IC and its dedicated software are primary concerns of this security target. Phase 3: Mask fabrication and IC wafer manufacturing – The masks used to manufacture the various IC layers are created from the layout design during phase 2; ROM masks for the Smartcard Embedded Software in a particular instance of the TOE are fabricated after receipt of the software in phase 2. Also, in this phase, wafers containing TOE dies with Smartcard Embedded Software are produced. At the end of this process each die is tested and has its pre-personalisation data injected into EEPROM (see section 2.4.2). The secure fabrication and handling of masks, and the security of manufacture, including handling of test software and pre-personalisation data are primary concerns of this security target. The TOE may be delivered at this stage as wafers (in which case each die will be set to User Mode). Alternatively, the TOE may be packaged by Renesas and delivered in COT form at the end of phase 4. If the TOE is to be delivered in COT form then at the end of phase 3 it is set to a constrained Test Mode, instead of User Mode, to allow testing of the IC after module manufacturing in phase 4. This security target covers TOE Delivery at either point, but where wafers are delivered at the end of phase 3, secure handling in phase 4 is a customer responsibility. Note that in all cases the TOE will be set to User Mode before TOE Delivery. Phase 4: IC Packaging – each wafer is cut into individual dies and its protective packaging applied, along with its contacts. The resulting module is then tested in Test Mode to ensure correct operation, after which it is set to User Mode. This leaves the IC ready for insertion into a plastic card. Phases 5-7: Smartcard finishing, personalisation and end-usage – these stages, and their security features, are determined by the customer, and are outside the scope of this security target. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 10 of 56 2.3.1 Test and User Modes During manufacturing and production (phases 2-4), the chip makes some mode transitions which affect the interface presented. These modes are as follows: Test mode makes the IC Dedicated Test Software available, which is used to ensure that only correctly working ICs are delivered. User mode makes the IC Dedicated Test Software unavailable and the TOE now provides only the functionality described in [HM]. The software interface presented will be determined by the Smartcard Embedded Software. As explained under the individual lifecycle phases above, the chip is always in test mode in phases 2 and 3. If TOE Delivery takes place at the end of phase 4, then the chip will be in the constrained test mode during phase 4, making a limited set of test functions available to test the correct operation of modules after packaging. However, the TOE is always in User Mode at the point of TOE Delivery, and the transition to User Mode is irreversible. 2.3.2 TOE Delivery As noted above, the TOE may be delivered at the end of either phase 3 or phase 4, as requested by the customer. In either case, the chip will be delivered in User Mode, and Renesas will apply secure delivery procedures for the transport of the TOE from Renesas premises. 2.4 TOE Environments 2.4.1 Development Environment Renesas’ development environment for the TOE has implemented security measures specifically to ensure the security of the TOE and of Smartcard Embedded Software and injection data used in manufacturing ICs for customers. As indicated in section 2.3, there are three areas of the development environment: Design sites Mask manufacture site Manufacturing sites These provide the following main security properties: Design sites Confidentiality and integrity of logical and physical design Testing of TOE security functionality Confidentiality and integrity of IC Dedicated Test Software Confidentiality and integrity of customer ROM code and injection data (i.e. the Smartcard Embedded Software for an instance of the TOE) AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 11 of 56 Mask manufacture site Confidentiality and integrity of customer ROM code and mask Confidentiality and integrity of design and base masks Manufacturing sites Confidentiality and integrity of base masks Confidentiality and integrity of customer ROM mask Confidentiality and integrity of test software Confidentiality and integrity of injection data Production of authentic TOE ICs, correctly implementing the design and including the customer Smartcard Embedded Software in ROM. Security issues for each of these areas are addressed by processes and procedures put in place by Renesas and within the scope of evaluation. The security measures include IT security to protect information stored on Renesas computer systems, as well as physical security measures for secure storage to ensure that design and manufacturing information and objects are only accessible to authorised staff with a need to know the information. Renesas' integrated security concept (ISC) covers the entire development process, from specification, through design and implementation to manufacturing and shipping. ISC is implemented through the use of standards and procedures that form part of the quality system at the heart of Renesas' business. The rigorous adoption and adherence to procedures, including those relating to security, is an integral part of the quality system at the heart of Renesas’ business. The security of the IC Dedicated Test Software at design and manufacturing sites is ensured by the same level of security measures as for the hardware design. This ensures that only authorised persons have access to the software and its related information. Smartcard Embedded Software is received from customers via a secure delivery procedure. Once received by Renesas, this software is also handled with the same level of security as for design information. As a further measure, the group handling customer software is separate from the IC design team. 2.4.2 Injection of Manufacturing Identification and Secret Data In general, although there will be a substantial amount of operating system and application software held in ROM, an IC will also require software to be added after it leaves the manufacturing environment. Operating system software may require additional parts or patches to be loaded, and increasingly applications are expected to be loaded and deleted after a smart card has been issued to users. In order to enable such addition (and deletion) of software to be done securely, there is a generic requirement for identification data and secret data, determined by the IC purchaser, to be injected during manufacture. The TOE supports this requirement by injecting identification data during the manufacturing process; this data uniquely identifies each IC. In addition, customers may choose to inject further data. The details of the data content and its location in memory are shown in [OPT]. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 12 of 56 3. TOE Security Environment 3.1 Assets This section defines the primary and secondary assets to be protected by the TOE. Section 3.1 of [BSI-PP-0002] gives the assets relating to the threats, and these are summarised below. The primary assets to be protected are classified as: User Data – this includes injection/pre-personalisation data and data generated and managed by the Smartcard Embedded Software (subject to adequate protection by the software, see A.Key-Function, A.Plat-Appl and A.Resp-Appl in section 3.2) Smartcard Embedded Software, comprising Hard-coded Embedded Software – this is fixed and generally consists of parts or all of the operating system, and parts or all of a number of applications Soft-coded Embedded Software – this may include parts of the operating system or applications. Both of these types of asset need to have their confidentiality and integrity protected. A further primary asset is: Correct operation of the TOE (including its random number generator). In particular this means that the Smartcard Embedded Software will be correctly executed, which includes the correct operation of the TOE’s functions. Because random numbers are likely to be used by embedded software for generating cryptographic keys, another primary asset is: the random numbers generated by the TOE1 Secondary assets are critical information about the TOE, including logical design data, physical design data, IC Dedicated Test Software and TSF data. In addition, the following will also contain information about the TOE. Initialisation Data and Pre-personalisation Data, specific development aids, test and characterisation related data, material for software development support, and photomasks. Such information and the ability to perform manipulations assist in threatening the primary assets. 1 The confidentiality of random numbers is generally protected by embedded software (which is responsible for requesting random numbers). However, it is important that random numbers should not be subject to leakage (cf. T.Leak-Inherent), because of their potential role in cryptographic key generation. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 13 of 56 Assets relating specifically to the Organisational Security Policy P.Process-TOE and Assumption A.Process-Card are given in section 3.1 of [BSI-PP-0002]. 3.2 Assumptions 3.2.1 Assumptions from [BSI-PP-0002] The following assumptions are made: A.Process-Card Protection during Packaging, Finishing and Personalisation It is assumed that security procedures are used by the recipient after delivery of the TOE by Renesas up to delivery to the end-user to maintain confidentiality and integrity of the TOE and of its manufacturing and test data (to prevent any possible copy, modification, retention, theft or unauthorised use). The exact requirements of this assumption will depend on the Smartcard Embedded Software. This means that the phases after TOE Delivery (refer to section 2.3) are assumed to be protected appropriately. For a preliminary list of assets to be protected, see section 3.1 of [BSI-PP-0002]. A.Plat-Appl Usage of Hardware Platform The Smartcard Embedded Software is designed so that the requirements from the following documents are met: (i) The TOE hardware manual [HM], current control supplement [CCF], user guidance manual [UGM], and the hardware application notes (ii) Findings of the TOE evaluation reports relevant for the Smartcard Embedded Software. A.Resp-Appl Treatment of User Data All User Data is owned by Smartcard Embedded Software. Therefore, it is assumed that security relevant User Data (especially cryptographic keys) are treated by the Smartcard Embedded Software as defined for the specific application context. This assumption requires that the Smartcard Embedded Software define and positively manage its security relevant User Data, in the manner required by the application context. Without this, the protection provided by the TOE itself may be of no use if the Smartcard Embedded Software itself allows data to be compromised. Examples of embedded software security concerns are given in section 8.2 of [BSI-PP-0002]. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 14 of 56 3.2.2 Assumptions from [PA] A.Key-Function Usage of Key-dependent Functions Key-dependent functions (if any) shall be implemented in the Smartcard Embedded Software in a way that they are not susceptible to leakage attacks (as described under T.Leak-Inherent and T.Leak-Forced). Note that here the routines which may compromise keys when being executed are part of the Smartcard Embedded Software. In contrast to this the threats T.Leak-Inherent and T.Leak-Forced address (i) the cryptographic routines which are part of the TOE and (ii) the processing of User Data including cryptographic keys. Note here that the functions considered in this assumption are part of the Smartcard Embedded Software; T.Leak-Inherent and T.Leak-Forced address the cryptographic functions that are part of the hardware. For example: consider the RSA encryption system that may be implemented in the Smartcard Embedded Software. This uses the modular arithmetic functions of the MMC. In this case the leakage characteristic of the implementation will depend partly on the hardware characteristics of the TOE and its MMC, partly on the way in which the embedded software uses the hardware. The properties of the TOE are assessed under this Security Target, but the software implementation is clearly outside the scope of the TOE evaluation. To assist embedded software developers to implement leak-resistant code, guidance on secure software implementation is given in [UGM]. 3.2.3 Other Assumptions A variety of keys and other security-critical data may be injected for use by Smartcard Embedded Software. These may include shared private keys, public/private key pairs, etc. This information could contribute to a cloning attack, or to breaking the security of an instance of the TOE (e.g. by compromising its keys). The integrity of this data is also vital to ensuring the security of the TOE (e.g. preventing unauthorised changes to mask code, IC design or keys). All data supplied for injection/pre-personalisation is assumed to be supported off-card in a secure manner: A.InjDatSupp Injected Data Support Data for injection/pre-personalisation will be supplied from the various bodies controlling the operations of the system in which the TOE is functioning, based on [OPT]. It is assumed that the generation, distribution, maintenance, and destruction of this data is adequately secure. 3.3 Threats 3.3.1 Threats Defined in [BSI-PP-0002] This section adopts the threats to ICs defined in section 3.3 of [BSI-PP-0002]. The TOE has the following security concerns, as in section 3.3 of [BSI-PP-0002]: AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 15 of 56 SC1 manipulation of User Data and of the Smartcard Embedded Software (while being executed/processed and while being stored in the TOE’s memories). SC2 disclosure of User Data and of the Smartcard Embedded Software (while being processed and while being stored in the TOE’s memories). SC3 deficiency of random numbers. These security concerns are refined below by defining specific threats. Note that manipulation of the TOE is only a means to threaten User Data or the Smartcard Embedded Software and does not in itself represent a successful attack. These security concerns are derived from considering the end-usage phase (phase 7) since Phase 1 and phases from TOE Delivery up to the end of phase 6 are covered by assumptions, and The development and production environment starting with phase 2 and ending with TOE Delivery are covered by an organisational security policy 3.3.1.1 Threats Derived from SC1-SC3 See section 3.3 of [BSI-PP-0002], and the example attack scenarios in section 8.3 of [BSI-PP- 0002]. For completeness, the threats are summarised below. T.Leak-Inherent Inherent Information Leakage An attacker may exploit information which is leaked from the TOE during usage of the Smartcard in order to disclose confidential data (User Data or TSF Data). No direct contact with the Smartcard internals is required here. Leakage may occur through emanations, variations in power consumption, I/O characteristics, clock frequency, or by changes in processing time requirements. Differential Power Analysis (DPA) is an example of an attack based on the inherent leakage threat. T.Phys-Probing Physical Probing An attacker may perform physical probing of the TOE in order to: (i) disclose User Data (ii) disclose/reconstruct the Smartcard Embedded Software (iii) disclose other critical operational information especially TSF data. Physical probing requires direct contact with the TOE circuit structures. Before attacks based on this threat can be mounted, hardware security mechanisms and layout characteristics need to be AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 16 of 56 identified. Determination of software design, including treatment of User Data, may also be a pre-requisite. T.Phys-Manipulation Physical Manipulation An attacker may physically modify the Smartcard in order to (i) modify security features or functions of the TOE (ii) modify security functions of the Smartcard Embedded Software (iii) modify User Data. Modification may be achieved through techniques commonly employed in IC failure analysis and IC reverse-engineering. The modification may result in the deactivation of a security function. As with T.Phys-Probing, before attacks based on this threat can be mounted, hardware security mechanisms and layout characteristics need to be identified. Determination of software design including treatment of User Data may be a pre-requisite. Changes to circuitry or data can be permanent or temporary. In contrast to malfunctions (see T.Malfunction), the attacker needs to gather significant knowledge about the TOE’s internal construction in order to launch a manipulation attack. T.Malfunction Malfunction due to Environmental Stress An attacker may cause a malfunction of the TSF or of the Smartcard Embedded Software by applying environmental stress in order to (i) deactivate or modify security features or functions of the TOE (ii) deactivate or modify security functions of the Smartcard Embedded Software. This may be achieved by operating the IC outside its normal operating conditions. Unlike T.Phys-Manipulation, attacks based on environmental stress can be launched without significant knowledge of the IC’s internal construction on the part of the attacker. However, to exploit the attack, the attacker needs information about the functional operation. T.Leak-Forced Forced Information Leakage An attacker may exploit information which is leaked from the TOE during usage of the smartcard in order to disclose confidential data (User Data or TSF Data), even if the information leakage is not inherent but caused by the attacker. This threat pertains to attacks where methods described in “Malfunction due to Environmental Stress” (T.Malfunction) and/or “Physical Manipulation” (T.Phys-Manipulation) are used to cause leakage from signals which normally do not contain significant information about secrets. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 17 of 56 Differential Fault Analysis (DFA) is an example of an attack based on the forced leakage threat. T.Abuse-Func Abuse of Functionality An attacker may use functions of the TOE which may not be used after TOE Delivery in order to (i) disclose or manipulate User Data (ii) manipulate (explore, bypass, deactivate or change) security features or functions of the TOE or of the Smartcard Embedded Software (iii) enable an attack. For the TOE, T.Abuse-Func concerns the threat of unauthorised access to the IC Dedicated Test Software, which is rendered inaccessible by placing the IC into User Mode before TOE Delivery (see section 2.3). T.RND Deficiency of Random Numbers An attacker may predict or obtain information about random numbers generated by the TOE, for instance because of a lack of entropy of the random numbers provided. An attacker may gather information about the random numbers produced. Malfunctions or premature ageing are also considered as they may assist in giving the attacker information about random numbers. Attacks on random number generation are significant because the random numbers generated may be used as secrets - e.g. to generate cryptographic keys. Under the threat T.RND, the attacker is assumed to take advantage of statistical properties of the random numbers generated by the TOE without specific knowledge about the RNG itself. 3.3.2 Other Threats The TOE makes available facilities that are useful for embedded software to use in addressing the threats that it may face. This introduces an additional security concern for the TOE: SC4 attacks on the Smartcard Embedded Software may be made, and the software may not be able to detect or respond to the attacks. T.NoSWDetect Inability of the TOE to detect an attack In a multi-layered or multi-application software environment, there may be attacks on one part of the Smartcard Embedded Software arising from another part. Smartcard Embedded Software execution may also be attacked via various means, with the intention of corrupting software execution in a specific or random way. If the AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 18 of 56 TOE cannot detect such attacks, then it cannot apply any countermeasures to protect itself. The TOE is concerned in particular to detect the following: (i) Attempts to access memory outside an area defined for the software being executed (ii) Attempts to make an illegal access (iii) Attempts to execute code from a type of memory not permitted by the software environment2 (iv) Attempts to write to EEPROM addresses containing data that should not be changed (v) Attempts to execute an illegal instruction code (vi) Attempts to alter registers controlling the operation of the TOE. For the purposes of this threat, an illegal access is one that is marked “ ” in the tables titled “Access” in the TOE memory map (section 17 of [HM]). In addition, among the accesses marked “○” in the tables, if a type of access allowed is noted under the circle, an access other than the allowed type of access is also an illegal access. This threat applies whether the “attack” is deliberate or due to errors, but all the attacks covered are launched from software. Inducing errors by external means, as covered in T.Phys- Manipulation, may also give rise to the same sort of error conditions as listed for T.NoSWDetect. T.NoSWResponse Inability of Smartcard Embedded Software to respond to an attack If Smartcard Embedded Software cannot detect a potential attack, or other dangerous condition, and has no ability to take action when such a condition is detected then there is a danger that it will not be able to prevent the attack continuing. This threat does not address the particular details of individual attacks, but recognises that Smartcard Embedded Software may make checks on its own state to enhance protection against a variety of attacks (including those aimed at inducing errors by software or external means). For such checks to be useful, there must also be ways for the software to respond to the attack (e.g. by preventing further processing). 3.4 Organisational Security Policies 3.4.1 Policy Requirement from [BSI-PP-0002] The following policy requirement is taken from section 3.4 of [BSI-PP-0002]. 2 The “software environment” is a term used to capture the definition of acceptable memory use for the software system using the TOE. This would usually be at the level of operating system software. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 19 of 56 P.Process-TOE Protection during TOE Development and Production The TOE Manufacturer must ensure that the development and production of the Smartcard Integrated Circuit (Phase 2 up to TOE Delivery) is secure so that no information is unintentionally made available for the operational phase of the TOE. For example, the confidentiality and integrity of design information and test data shall be guaranteed; access to samples, development tools and other material shall be restricted to authorised persons only; scrap will be destroyed etc. This not only pertains to the TOE but also to all information and material exchanged with the developer of the Smartcard Embedded Software and therefore especially to the Smartcard Embedded Software itself. This includes the delivery (exchange) procedures for Phase 1 and the Phases after TOE Delivery as far as they can be controlled by the TOE Manufacturer. An accurate identification must be established for the TOE. This requires that each instantiation of the TOE carries this unique identification. Assets relating specifically to P.Process-TOE are given in section 3.1 of [BSI-PP-0002]. Renesas implement the security measures to satisfy this policy requirement, and these are assessed as part of evaluation and certification against this ST. However, since they are not directly relevant to users of the TOE, the detailed measures and processes that implement the policy are not given here. Note that the inclusion of identification information in EEPROM is described in more detail in section 2.4.2. This part of the policy establishes a basis for evaluation and security of software running on the chip, by ensuring that a TOE can be identified. Note that procedural measures (including Renesas’ secure delivery procedures) will generally be required to ensure that TOE ICs are genuine, unless the Smartcard Embedded Software contains functionality to authenticate the IC3 . P.Process-TOE covers identification of hard-coded Embedded Software (via identification of the ROM mask); soft-coded Embedded Software will generally need to provide its own identification. 3.4.2 Policy Requirement from [PA] As an additional policy, the TOE provides specific security functionality which can be used by the Smartcard Embedded Software for cryptographic algorithm implementation. The policy P.Add-Functions is therefore adopted from [PA]. In the following policy, specific security functionality is listed which is not derived from threats identified for the TOE’s environment because it can only be decided in the context of the smartcard application, against which threats the Smartcard Embedded Software will use the specific security functionality. 3 For example, a hash or digital signature over a known area of memory might be provided by software. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 20 of 56 P.Add-Functions Additional Specific Security Functionality The TOE shall provide the following specific security functionality to the Smartcard Embedded Software: Data Encryption Standard (DES) AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 21 of 56 4. Security Objectives 4.1 TOE Security Objectives 4.1.1 Objectives from [BSI-PP-0002] The TOE shares the following security considerations from section 4.1 of [BSI-PP-0002]: SG1 maintain the integrity of User Data and of the Smartcard Embedded Software (when being executed/processed and when being stored in the TOE’s memories). SG2 maintain the confidentiality of User Data and of the Smartcard Embedded Software (when being processed and when being stored in the TOE’s memories). SG3 provide random numbers. These security considerations are refined below by defining security objectives as required by the Common Criteria. Note that maintaining the integrity of the TOE is a means to achieve these objectives. O.Leak-Inherent Protection against Inherent Information Leakage The TOE must provide protection against disclosure of confidential data (User Data or TSF Data) stored and/or processed in the smartcard IC by measurement and analysis of The shape and amplitude of signals (for example on the power, clock, or I/O lines) the time between events found by measuring signals (for example on the power, clock, or I/O lines). This objective pertains to measurements with subsequent complex signal processing whereas O.Phys-Probing is about direct measurements on elements on the chip surface. Note that this objective relates to security features provided by the TOE itself, and Smartcard Embedded Software should ensure that the security features are appropriately used in conjunction with any additional leakage countermeasures implemented in software (cf. A.Plat- Appl and A.Resp-Appl in section 3.2.1). O.Phys-Probing Protection against Physical Probing The TOE must provide protection against disclosure of User Data, against the disclosure/reconstruction of the Smartcard Embedded Software, and against the disclosure of other critical operational information. This includes protection against measuring through galvanic contacts, which is direct physical probing on the chip’s surface other than on pads being bonded (using standard tools for measuring voltage and current) AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 22 of 56 measuring not using galvanic contacts but other types of physical interaction between charges (using tools used in solid-state physics research and IC failure analysis). The TOE must be designed and fabricated so that it requires a combination of equipment, knowledge, skill, and time to be able to derive detailed design information or other information which could be used to compromise security through such a physical attack. O.Phys-Probing assumes that the attacker has first performed reverse-engineering to understand the design and its properties and functions. O.Malfunction Protection against Malfunctions The TOE must ensure its correct operation. The TOE must prevent itself from being operated outside the normal operating conditions where reliability and secure operation has not been proven or tested. This is to prevent errors. The environmental conditions may include voltage, clock frequency, temperature, or external energy fields. An attacker may also attempt to cause the chip to malfunction by using a direct galvanic contact on elements on the chip surface. This is considered as being a manipulation (see O.Phys-Manipulation) provided that detailed knowledge about the TOE’s internal construction is required and the attack is performed in a controlled manner. O.Phys-Manipulation Protection against Physical Manipulation The TOE must provide protection against physical manipulation of the TOE (including its software and TSF data), the Smartcard Embedded Software and User Data. This includes protection against reverse-engineering (understanding the design and its properties and functions) manipulation of the hardware and any data controlled manipulation of memory contents (User Data). The TOE must be designed and fabricated so that it requires a combination of equipment, knowledge, skill, and time to be able to derive detailed design information or other information which could be used to compromise security through such a physical attack. O.Leak-Forced Protection against Forced Information Leakage The Smartcard must be protected against disclosure of confidential data (User Data or TSF data) processed in the Card (using methods as described under O.Leak-Inherent) even if the information leakage is not inherent but caused by the attacker AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 23 of 56 by forcing a malfunction (cf. O.Malfunction) and/or by a physical manipulation (cf. O.Phys-Manipulation). This objective includes resistance to attacks where T.Phys-Manipulation and T.Leak-Inherent are combined. O.Abuse-Func Protection against Abuse of Functionality The TOE must prevent abuse of IC Dedicated Test Software (which may not be used after TOE Delivery) that would (i) disclose critical User Data (ii) manipulate critical User Data of the Smartcard Embedded Software (iii) manipulate Soft-coded Smartcard Embedded Software (iv) bypass, deactivate, change or explore security features or functions of the TOE. O.Identification TOE Identification The TOE must provide a means to store Initialisation Data and Pre- personalisation Data in its non-volatile memory. The Initialisation Data (or parts of them) are used for TOE identification. The TOE identification data is described in section 2.4.2. O.RND Random Numbers The TOE will ensure the cryptographic quality of random number generation. For instance, random numbers shall not be predictable and shall have sufficient entropy. The TOE will ensure that no information about the produced random numbers is available to an attacker since they might be used, for instance, to generate cryptographic keys. 4.1.2 Objectives Based on [PA] This section includes an objective for the TOE to provide a DES function, which is based on O.Add-Functions in [PA]. The modular arithmetic functions that are the basis for implementation of RSA and other asymmetric cryptographic algorithms in Smartcard Embedded Software are part of the TOE functionality, but because they do not directly implement RSA (or other asymmetric systems), they are not included as cryptographic functions here. O.Add-Functions Additional Specific Security Functionality The TOE must provide the following specific security functionality to the Smartcard Embedded Software: Data Encryption Standard (DES) AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 24 of 56 4.1.3 Other Objectives The TOE offers additional facilities to protect embedded software from corrupted, erroneous, or malicious software. The same facilities may protect from some results of attempts at physical manipulation (cf. O.Phys-Manipulation). A further security consideration is therefore derived from SC4 in section 3.3.2. SG4 software should be given the ability to detect and respond to attacks. This leads to objectives that O.SWDetect Detection of potential attacks by the TOE The following conditions shall be detected as an aid to identifying potential attacks: (i) Attempts to access memory outside an area defined for the software being executed (ii) Attempts to make an illegal access (iii) Attempts to execute code from a type of memory not permitted by the software environment4 (iv) Attempts to write to EEPROM addresses containing data that should not be changed (v) Attempts to execute an illegal instruction code (vi) Attempts to alter registers controlling the operation of the TOE. The Smartcard Embedded Software itself will determine the memory area for (i), the types of memory permitted for (iii), and the protected EEPROM addressed for (iv). O.SWResponse Response to potential attacks by Smartcard Embedded Software The TOE shall allow Smartcard Embedded Software to: (i) periodically interrupt processing to execute a known piece of Smartcard Embedded Software (ii) cause the processor to enter the reset state. Executing a known piece of embedded software periodically gives embedded software the ability to check the execution state for any conditions that it wishes to monitor (in addition to those indicated under O.SWDetect above) and stop execution, or take some other action, if it detects a potential attack or other dangerous condition. 4 The “software environment” is a term used to capture the definition of acceptable memory use for the software system using the TOE. This would usually be at the level of operating system software. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 25 of 56 4.2 Environment Security Objectives 4.2.1 Environment Security Objectives from [BSI-PP-0002] Phase 1 OE.Plat-Appl Usage of Hardware Platform The Smartcard Embedded Software shall be designed so that the requirements from the following documents are met: (i) The TOE hardware manual [HM], current control supplement [CCF], user guidance manual [UGM], and the TOE application notes. (ii) Findings of the TOE evaluation reports relevant to the Smartcard Embedded Software. Because the TOE implements additional specific security functionality (as in O.Add-Functions), OE.Plat-Appl covers the use of these functions by Smartcard Embedded Software as follows: If required, the Smartcard Embedded Software shall use these cryptographic services of the TOE and their interface as specified. When key-dependent functions implemented in the Smartcard Embedded Software are just being executed, the Smartcard Embedded Software must provide protection against disclosure of confidential data (User Data) stored and/or processed in the TOE by using the methods described under “Inherent Information Leakage (T.Leak-Inherent)” and “Forced Information Leakage (T.Leak-Forced)“. OE.Resp-Appl Treatment of User Data Security relevant User Data (especially cryptographic keys) are treated by the Smartcard Embedded Software as required by the security needs of the specific application context. Because the TOE implements additional specific security functionality (as in O.Add-Functions), OE.Resp-Appl covers the use of these functions by Smartcard Embedded Software as follows: By definition cipher or plain text data and cryptographic keys are User Data. The Smartcard Embedded Software shall treat these data appropriately, use only proper secret keys (chosen from a large key space) as input for the cryptographic function of the TOE and use keys and functions appropriately in order to ensure the strength of cryptographic operation. This means that keys are treated as confidential as soon as they are generated. The keys must be unique with a very high probability, as well as cryptographically strong. For example, it must be ensured that it is not possible to derive the private key from a public key if asymmetric algorithms are used. If keys are imported into the TOE and/or derived from other keys, quality and confidentiality must be maintained. This AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 26 of 56 implies that appropriate key management has to be realised in the environment. From Phase 2 until TOE Delivery OE.Process-TOE Protection during TOE Development and Production The TOE Manufacturer must ensure that the development and production of the Smartcard Integrated Circuit (Phases 2 and 3 up to TOE Delivery) is secure so that no information is unintentionally made available for the operational phase of the TOE. For example, the confidentiality and integrity of design information and test data must be guaranteed, access to samples, development tools and other material must be restricted to authorised persons only, scrap must be destroyed. This not only pertains to the TOE but also to all information and material exchanged with the developer of the Smartcard Embedded Software and therefore especially to the Smartcard Embedded Software itself. This includes the delivery (exchange) procedures for Phase 1 and the Phases after TOE Delivery as far as they can be controlled by the TOE Manufacturer. An accurate identification must be established for the TOE. This requires that each instantiation of the TOE carries this unique identification. In order to make this practical, electronic identification shall be possible. Assets relating specifically to the Organisational Security Policy P.Process-TOE (which is the source of this objective) are given in section 3.1 of [BSI-PP-0002]. From TOE Delivery until the beginning of Phase 7 OE.Process-Card Protection during Packaging, Finishing and Personalisation Security procedures shall be used after TOE Delivery up to delivery to the end-user to maintain confidentiality and integrity of the TOE and of its manufacturing and test data (to prevent any possible copy, modification, retention, theft or unauthorised use). This means that Phases after TOE Delivery up to the end of Phase 6 must be protected appropriately. Assets relating specifically to the assumption A.Process-Card (which is the source of this objective) are given in section 3.1 of [BSI-PP-0002]. The precise nature of the protection required will depend on the application context. 4.2.2 Other Environment Security Objectives For injected/pre-personalisation data, the sources and holders of the data need to support its security requirements. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 27 of 56 OE.InjDatSupp Injected Data Support All data for injections/pre-personalisation shall be generated, distributed, maintained and destroyed in an adequately secure fashion. In general, the data shall be protected for both confidentiality and integrity. Renesas ensures a secure interface with suppliers of this data by using the injection approach in section 2.4.2. Transmission of data to Renesas is secured by a variety of measures dependent on the transmission medium (e.g. ROM data may be sent by encrypted e-mail). The data is securely stored within the Renesas environment according to the medium. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 28 of 56 5. IT Security Requirements 5.1 TOE Security Requirements The functional requirements for the TOE come from 3 sources: [BSI-PP-0002] These SFRs cover the core smart card IC requirements: operating state – FRU_FLT.2 describes the usual operating conditions and requires the TOE to maintain a secure state; FPT_FLS.1 requires a secure response to exceptional operating conditions; FPT_SEP.1 requires the TOE to ensure that the secure responses to operating conditions are independent of software (since, for example, some software could be malicious) controls over IC Dedicated Test Software – FMT_LIM.1 and FMT_LIM.2 require that the use of IC Dedicated Test Software for manufacturing tests must not allow security to be compromised after TOE Delivery storage of identification/pre-personalisation data – FAU_SAS.1 requires that the TOE be capable of storing such data protection against physical attacks – FPT_PHP.3 requires the TOE to be protected against physical tampering attacks Protection against leakage – FDP_ITT.1 and FPT_ITT.1 require protection of data against leakage as it moves between components on the IC, and FDP_IFC.1 provides the policy of protection for data Random number generation – FCS_RND.1 requires generation of good quality random numbers [PA] This SFR covers DES cryptographic requirements. DES – FCS_COP.1 requires the implementation of DES in ECB mode TOE features Some SFRs introduced from [BSI-PP-0002] are given a wider scope to reflect additional security features of the TOE and functions which support secure features in embedded software: Additional failure detection – the scope of FPT_FLS.1 includes additional software failure conditions trapped by the TOE support to embedded software to run tests at certain points during execution (enabling measures such as state integrity tests) and the ability of embedded software to cause a hardware reset (this is covered under FPT_FLS.1 in section 5.1.1.1). Controlled writes – FDP_ACC.1 [CRP] and FDP_ACF.1 [CRP] are added to represent the way in which some registers are protected against changes other than from embedded software executing in ROM; AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 29 of 56 FDP_ACC.1 [WPP] and FDP_ACF.1 [CRP] specify the ability to prevent writing to chosen EEPROM pages. Note that all SFRs are drawn from [CC/2] except for FCS_RND.1, FMT_LIM.1 & 2, and FAU_SAS.1, which are all defined in section 8 of [BSI-PP-0002]. 5.1.1 TOE Security Functional Requirements from [BSI-PP-0002] In the specifications of SFRs listed below, ‘Refinement’ sections are taken from [BSI-PP-0002]; ‘Application Notes’ add information specific to the TOE. 5.1.1.1 Operating Conditions The TOE implements a pair of security functional requirements that ensure it operates within conditions under which it can maintain a secure state. This is represented in [BSI-PP-0002, fig 14], reproduced below: Limited fault tolerance (FRU_FLT.2) Failure with preservation of secure state (FPT_FLS.1) operating conditions operating conditions max. min. max. min. Technical limits without reduction due to FPT_FLS.1 Usable limits of the product as enforced due to FPT_FLS.1 Figure 5-1: Paradigm Regarding Operating Conditions Erroneous software conditions (some of which could arise from corruptions due to operating conditions) are dealt with under FPT_FLS.1. FRU_FLT.2 Limited fault tolerance Hierarchical to: FRU_FLT.1 FRU_FLT.2.1 The TSF shall ensure the operation of all the TOE’s capabilities when the following failures occur: exposure to operating conditions which are not detected according to the requirement Failure with preservation of secure state (FPT_FLS.1). Dependencies: FPT_FLS.1 Failure with preservation of secure state Refinement: The term “failure” above means “circumstances”. The TOE prevents failures for the “circumstances” defined above. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 30 of 56 FRU_FLT.2 thus states the condition for normal secure operation of the TOE functions (including coprocessors) within its expected operating conditions. FPT_FLS.1 Failure with preservation of secure state Hierarchical to: No other components FPT_FLS.1.1 The TSF shall preserve a secure state when the following types of failures occur: exposure to operating conditions which may not be tolerated according to the requirement Limited fault tolerance (FRU_FLT.2) and where therefore a malfunction could occur. Dependencies: ADV_SPM.1 Informal TOE security policy model Refinement 1: The term “failure” above also covers “circumstances”. Then the TOE prevents failures for the “circumstances” defined above. The refinement above is defined in [BSI-PP-0002]. An additional refinement is made here to capture features specific to the TOE. Refinement 2: The term “failure” above also covers the following: (i) Attempts to access memory outside an area defined for the software being executed (ii) Attempts to make an illegal access (iii) Attempts to execute code from a type of memory not permitted by the software environment5 (iv) Attempts to execute an illegal instruction code (v) Processor halted by Smartcard Embedded Software Application notes: 1. The TOE is required to implement a periodic interrupt, and an interrupt whenever a write to EEPROM takes place, to enable detection of failure conditions and preservation of a secure state by Smartcard Embedded Software. FPT_SEP.1 TSF domain separation Hierarchical to: No other components FPT_SEP.1.1 The TSF shall maintain a security domain for its own execution that protects it from interference and tampering by untrusted subjects. FPT_SEP.1.2 The TSF shall enforce separation between the security domains of subjects in the TSC. 5 The “software environment” is a term used to capture the definition of acceptable memory use for the software system using the TOE. This would usually be at the level of operating system software. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 31 of 56 Dependencies: No dependencies. Refinement: The components which support the SFRs “Limited fault tolerance (FRU_FLT.2)” and “Failure with preservation of secure state (FPT_FLS.1)” shall be protected from interference of the Smartcard Embedded Software. 5.1.1.2 Protection Against Abuse of Functionality The TOE controls access to test mode. Following [BSI-PP-0002], this is specified using the extended functional family FMT_LIM, defined in section 8.5 of [BSI-PP-0002]. FMT_LIM.1 Limited capabilities Hierarchical to: No other components FMT_LIM.1.1 The TSF shall be designed in a manner that limits their capabilities so that in conjunction with “Limited availability (FMT_LIM.2)” the following policy is enforced: Deploying Test Features after TOE Delivery does not allow User Data to be disclosed or manipulated, TSF data to be disclosed or manipulated, software to be reconstructed and substantial information about construction of TSF to be gathered which may enable other attacks. Dependencies: FMT_LIM.2 Limited availability. Application notes: 1. The “capabilities” referred to in FMT_LIM.1 are the functions implemented in the IC Dedicated Test Software. FMT_LIM.2 Limited availability Hierarchical to: No other components FMT_LIM.2.1 The TSF shall be designed in a manner that limits their availability so that in conjunction with “Limited capabilities (FMT_LIM.1)” the following policy is enforced: Deploying Test Features after TOE Delivery does not allow User Data to be disclosed or manipulated, TSF data to be disclosed or manipulated, software to be reconstructed and substantial information about construction of TSF to be gathered which may enable other attacks. Dependencies: FMT_LIM.1 Limited capabilities. Application notes: 1. The “availability” referred to in FMT_LIM.2 are the functions implemented in the IC Dedicated Test Software. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 32 of 56 5.1.1.3 Storage of Production Data The TOE stores identification/pre-personalisation data as described in section 2.4.2. This is included in [BSI-PP-0002] as the CC Part 2 extended functional component FAU_SAS.1, replacing FAU_GEN.1, and defined in section 8.6 of [BSI-PP-0002]. FAU_SAS.1 Audit storage Hierarchical to: No other components FAU_SAS.1.1 The TSF shall provide test personnel before TOE Delivery with the capability to store the Initialisation Data and/or Pre-personalisation Data and/or supplements of the Smartcard Embedded Software in the audit records. Dependencies: No dependencies Application notes: 1. The data covered by “Initialisation Data and/or Pre-personalisation Data and/or supplements of the Smartcard Embedded Software” is as identified in section 2.4.2. The function Audit storage (FAU_SAS.1) is subject to the limitations as specified by Limited availability (FMT_LIM.2) above. 5.1.1.4 Protection against Physical Manipulation and Probing FPT_PHP.3 Resistance to physical attack Hierarchical to: No other components FPT_PHP.3.1 The TSF shall resist physical manipulation and physical probing to the TSF by responding automatically such that the TSP is not violated. Dependencies: No dependencies Refinement: The TOE will implement appropriate measures to continuously counter physical manipulation and physical probing. Due to the nature of these attacks (especially manipulation) the TOE can by no means detect attacks on all of its elements. Therefore, permanent protection against these attacks is required ensuring that the TSP could not be violated at any time. Hence, “automatic response” means here (i) assuming that there might be an attack at any time and (ii) countermeasures are provided at any time. 5.1.1.5 Protection against Leakage FDP_ITT.1 Basic internal transfer protection Hierarchical to: No other components AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 33 of 56 FDP_ITT.1.1 The TSF shall enforce the Data Processing Policy to prevent the disclosure of user data when it is transmitted between physically- separated parts of the TOE. Dependencies: [FDP_ACC.1 Subset access control, or FDP_IFC.1 Subset information flow control] Refinement: The different memories, the CPU and other functional units of the TOE (e.g. a cryptographic co-processor) are seen as physically- separated parts of the TOE. The Data Processing Policy is defined under FDP_IFC.1 below. FPT_ITT.1 Basic internal TSF data transfer protection Hierarchical to: No other components FPT_ITT.1.1 The TSF shall protect TSF data from disclosure when it is transmitted between separate parts of the TOE. Dependencies: No dependencies. Refinement: The different memories, the CPU and other functional units of the TOE (e.g. a cryptographic co-processor) are seen as separated parts of the TOE. This requirement is equivalent to FDP_ITT.1 above but refers to TSF data instead of User Data. Therefore, it should be understood as to refer to the same Data Processing Policy defined under FDP_IFC.1 below. FDP_IFC.1 Subset information flow control Hierarchical to: No other components FDP_IFC.1.1 The TSF shall enforce the Data Processing Policy on all confidential data when they are processed or transferred by the TOE or by the Smartcard Embedded Software. Dependencies: FDP_IFF.1 Simple security attributes Data Processing Policy User Data and TSF data shall not be accessible from the TOE except when the Smartcard Embedded Software decides to communicate the User Data via such an external interface. The protection shall be applied to confidential data only, but without the distinction of attributes controlled by the Smartcard Embedded Software. 5.1.1.6 Cryptographic Support The TOE generates random numbers that can be used for cryptographic key generation. To capture the functional requirement, the family FCS_RND, defined in section 8.4 of [BSI-PP- 0002] is used. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 34 of 56 FCS_RND.1 Quality metric for random numbers FCS_RND.1.1 The TSF shall provide a mechanism to generate random numbers that meet the requirements of the monobit, poker, runs, long run, and autocorrelation tests in [AIS31]. 5.1.2 TOE Security Functional Requirements Based on [PA] 5.1.2.1 Cryptographic Support The TOE provides a DES coprocessor. The DES coprocessor can be used to implement single or triple DES. FCS_COP.1 Cryptographic operation FCS_COP.1 is iterated here to address both the DES encryption and decryption (FCS_COP.1 [DES]). DES Encryption and Decryption FCS_COP.1 [DES] Hierarchical to: No other components FCS_COP.1.1 [DES] The TSF shall perform encryption and decryption in accordance with a specified cryptographic algorithm Data Encryption Standard (DES) and cryptographic key sizes of 56 bit that meet the following standards: U.S. Department of Commerce / National Bureau of Standards Data Encryption Standard (DES), FIPS PUB 46-3, 1999 October 25 Dependencies: [FDP_ITC.1 Import of user data without security attributes or FCS_CKM.1 Cryptographic key generation] FCS_CKM.4 Cryptographic key destruction FMT_MSA.2 Secure security attributes Application notes: 1. Although the TOE provides a DES coprocessor, DES is only ever used as an encryption function in the context of particular Smartcard Embedded Software. Modular Arithmetic for Asymmetric Encryption and Decryption The TOE also provides a modular multiplication coprocessor (see section 3 of [HM]) which can be used for the implementation of RSA (or other asymmetric algorithms) in Smartcard Embedded Software. This can be used to build other FCS_COP functions in software. Because the TOE provides this generic functionality, rather than a specific cryptographic function such as RSA encryption or signature, the coprocessor functionality is covered under FRU_FLT.2. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 35 of 56 5.1.3 Other TOE Security Functional Requirements FDP_ACC.1 Subset access control FDP_ACC.1 is iterated here to address both the control over software to write to certain controlled registers (FDP_ACC.1 [CRP]) and software to write to protected pages of EEPROM memory (FDP_ACC.1 [WPP]). FDP_ACC.1 [CRP] Hierarchical to: No other components FDP_ACC.1.1 [CRP] The TSF shall enforce the Controlled-Register Policy on software to set bits in defined, security-relevant registers. Here, policy: Controlled-Register Policy Subjects: software Objects: bits in defined, security-relevant registers Operations: to set Controlled-Register Policy The ability to set the values in the controlled registers is restricted to software instructions executed in ROM. Dependencies: FDP_ACF.1 Security attribute based access control Application Notes: 1. The controlled registers are those defined in FDP_ACC.1.1 [CRP]. FDP_ACC.1 [WPP] Hierarchical to: No other components FDP_ACC.1.1 [WPP] The TSF shall enforce the Write-Protect Policy on software to write to EEPROM. Here, policy: Write-Protect Policy Subjects: software Objects: EEPROM Operations: to write Write-Protect Policy An attempt to write to EEPROM shall fail, leaving the previous memory contents unaltered if the relevant EEPROM page is write protected. Once a page is write-protected, this protection cannot be removed. Dependencies: FDP_ACF.1 Security attribute based access control Application Notes: AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 36 of 56 1. The setting of write protection is described in [HM]. 2. All modes of EEPROM write (see [HM]) are covered by this policy. FDP_ACF.1 Security attribute based access control FDP_ACF.1 is iterated here to address both the security attribute based access control over software to write to certain controlled registers (FDP_ACF.1 [CRP]) and software to write to protected pages of EEPROM memory (FDP_ACF.1 [WPP]). FDP_ACF.1 [CRP] Hierarchical to: No other components FDP_ACF.1.1 [CRP]6 The TSF shall enforce the Controlled-Register Policy to objects based on the following: Subject: software running on the ROM Object: control registers relating to the FMU attributes: to have read and/or write access normally FDP_ACF.1.2 [CRP] The TSF shall enforce the following rules to determine if an operation among controlled subjects and controlled objects is allowed: evaluate the corresponding permission control information: “The ability to set the values in the controlled registers is restricted to software operations executed from the ROM.” before, during or after the access so that accesses to be denied can not be utilised by the subject attempting to perform the operation. FDP_ACF.1.3 [CRP] The TSF shall explicitly authorise access of subjects to objects based on the following additional rules: none. FDP_ACF.1.4 [CRP] The TSF shall explicitly deny access of subjects to objects based on the following additional rules: none. Dependencies: FDP_ACC.1 Subset access control FMT_MSA.3 Static attribute initialisation FDP_ACF.1 [WPP] Hierarchical to: No other components 6 FDP_ACF.1.1 is changed as follows according to Final Interpretation 103 FDP_ACF.1.1 The TSF shall enforce the [assignment: access control SFP] to objects based on the following: [assignment: list of subjects and objects controlled under the indicated SFP, and. for each, the SFP-relevant security attributes, or named groups of SFP-relevant security attributes]. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 37 of 56 FDP_ACF.1.1 [WPP]6 The TSF shall enforce the Write Protect Policy to objects based on the memory area where the access is performed and the operation to be performed. FDP_ACF.1.2 [WPP] The TSF shall enforce the following rules to determine if an operation among controlled subjects and controlled objects is allowed: evaluate the corresponding permission control information: “An attempt to write to EEPROM shall fail, leaving the previous memory contents unaltered if write protection is set for the relevant EEPROM page. Once a page is write-protected, this protection cannot be removed.” before, during or after the access so that accesses to be denied can not be utilised by the subject attempting to perform the operation. FDP_ACF.1.3 [WPP] The TSF shall explicitly authorise access of subjects to objects based on the following additional rules: none. FDP_ACF.1.4 [WPP] The TSF shall explicitly deny access of subjects to objects based on the following additional rules: none. Dependencies: FDP_ACC.1 Subset access control FMT_MSA.3 Static attribute initialisation 5.1.4 TOE Security Assurance Requirements The assurance level for this Security Target is EAL4. The minimum strength of function is SOF-basic. Note that the strength of the cryptographic algorithms is out of the scope of the TOE. 5.2 Security Requirements for the Environment 5.2.1 Security Requirements for the IT Environment from [PA] In section 5.2.1 of [BSI-PP-0002], only non-IT security requirements are placed on the environment (see section 5.2.2). Although these requirements are applicable to Smartcard Embedded Software, it is not necessary or appropriate to place specific functional requirements. However, the following requirements for the environment are adopted from [PA]. The security functional requirement “Cryptographic operation (FCS_COP.1)” met by the TOE has the following dependencies - [FDP_ITC.1 Import of user data without security attributes or FCS_CKM.1 Cryptographic key generation], - FCS_CKM.4 Cryptographic key destruction, - FMT_MSA.2 Secure security attributes. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 38 of 56 These requirements all address the appropriate management of cryptographic keys used by the specified cryptographic function. All requirements concerning key management shall be fulfilled by the environment since the Smartcard Embedded Software is designed for a specific application context and uses the cryptographic functions provided by the TOE. Note that, however, for FCS_COP.1, the dependencies are unfulfilled because the environment is unknown (it is an issue for the user of the chip of course). The environment shall meet the requirement “Import of user data without security attributes (FDP_ITC.1)” or “Cryptographic key generation (FCS_CKM.1)” as specified below. Note that, however, for FDP_ITC.1, the operations are deliberately uncompleted and dependencies unfulfilled because the environment is unknown (it is an issue for the user of the chip of course). FDP_ITC.1 Import of user data without security attributes Hierarchical to: No other components. FDP_ITC.1.1 The TSF shall enforce the [assignment: access control SFP and/or information flow control SFP] when importing user data, controlled under the SFP, from outside of the TSC. FDP_ITC.1.2 The TSF shall ignore any security attributes associated with the user data when imported from outside the TSC. FDP_ITC.1.3 The TSF shall enforce the following rules when importing user data controlled under the SFP from outside the TSC: [assignment: additional importation control rules]. Dependencies: [FDP_ACC.1 Subset access control, or FDP_IFC.1 Subset information flow control] FMT_MSA.3 Static attribute initialisation FCS_CKM.1 Cryptographic key generation Hierarchical to: No other components. FCS_CKM.1.1 The TSF shall generate cryptographic keys in accordance with a specified cryptographic key generation algorithm [assignment: cryptographic key generation algorithm] and specified cryptographic key sizes [assignment: cryptographic key sizes], that meet the following: [assignment: list of standards]. Dependencies: [FCS_CKM.2 Cryptographic key distribution or FCS_COP.1 Cryptographic operation] FCS_CKM.4 Cryptographic key destruction FMT_MSA.2 Secure security attributes The environment shall meet the requirement “Cryptographic key destruction (FCS_CKM.4)” as specified below. Note that, however, for FCS_CKM.4, the operations are deliberately AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 39 of 56 uncompleted and dependencies unfulfilled because the environment is unknown (it is an issue for the user of the chip of course). FCS_CKM.4 Cryptographic key destruction Hierarchical to: No other components. FCS_CKM.4.1 The TSF shall destroy cryptographic keys in accordance with a specified cryptographic key destruction method [assignment: cryptographic key destruction method] that meets the following: [assignment: list of standards]. Dependencies: [FDP_ITC.1 Import of user data without security attributes or FCS_CKM.1 Cryptographic key generation] FMT_MSA.2 Secure security attributes The environment shall meet the requirement “Secure security attributes (FMT_MSA.2)” as specified below. Note that, however, for FMT_MSA.2, the operations are deliberately uncompleted and dependencies unfulfilled because the environment is unknown (it is an issue for the user of the chip of course). FMT_MSA.2 Secure security attributes Hierarchical to: No other components. FMT_MSA.2.1 The TSF shall ensure that only secure values are accepted for security attributes. Dependencies: ADV_SPM.1 Informal TOE security policy model [FDP_ACC.1 Subset access control or FDP_IFC.1 Subset information flow control] FMT_MSA.1 Management of security attributes FMT_SMR.1 Security roles 5.2.2 Security Requirements for the Non-IT Environment 5.2.2.1 Security Requirements for the Non-IT Environment from [BSI-PP-0002] As in section 5.2.2 of [BSI-PP-0002], this ST applies the following requirements: RE.Phase-1 Design and Implementation of the Smartcard Embedded Software The developers shall design and implement the Smartcard Embedded Software in such way that it meets the requirements from the following documents: (i) The TOE hardware manual [HM], current control supplement [CCF], user guidance manual [UGM], and the hardware application notes. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 40 of 56 (ii) Major findings of the hardware evaluation reports relevant for the Smartcard Embedded Software. The developers shall implement the Smartcard Embedded Software in a way that it protects security relevant User Data (especially cryptographic keys) as required by the security needs of the specific application context. In particular, the Smartcard Embedded Software shall not disclose secret User Data to unauthorised users or processes as defined for the application context. Similarly the Smartcard Embedded Software shall not allow unauthorised users or processes to use or modify security relevant User Data. RE.Process-Card Protection during Packaging, Finishing and Personalisation The Card Manufacturer (after TOE Delivery up to the end of Phase 6) shall use adequate security measures to maintain confidentiality and integrity of the TOE and of its manufacturing and test data (to prevent any possible copy, modification, retention, theft or unauthorised use). Section 8.2.2 of [BSI-PP-0002] gives examples of ways in which Smartcard Embedded Software may implement security issues. The TOE does not itself require any of these functions to be implemented in software – this is entirely a decision to be based on the software context. However, the TOE aims to provide support for software implementation of FDP_SDI.1 and FPT_AMT.1 (the examples given in [BSI-PP-0002]) through features such as the EWE interrupt – cf. FPT_FLS.1 in section 5.1.1.1 and SF.ESFunctions in section 6.1. 5.2.2.2 Security Requirements for the Non-IT Environment from [PA] For implementation of cryptographic functions in Smartcard Embedded Software, the following requirement from [PA] is included: RE.Cipher Cipher Schemes The developers of Smartcard Embedded Software must not implement routines in a way which may compromise keys when the routines are executed as part of the Smartcard Embedded Software. Performing functions which access cryptographic keys could allow an attacker to misuse these functions to gather information about the key which is used in the computation of the function. Keys must be kept confidential as soon as they are generated. The keys must be unique with a very high probability, as well as cryptographically strong. For example, it must be ensured that it is not possible to derive the private key from a public key if asymmetric algorithms are used. If keys are imported into the TOE and/or derived from other keys quality and confidentiality must be maintained. This implies that an appropriate key management has to be realised in the environment. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 41 of 56 6. TOE Summary Specification 6.1 TOE Security Functions 1. SF.HWProtect The TOE is protected from attacks on the operation of the IC hardware. The protection features include detection of out-of-range supply voltages, frequencies or temperatures, detection of illegal address or instruction, and physical security. Detection of an error causes the AE45X1-C to enter a reset state. Correct operating ranges are defined in [HM] and [CCF]. The memory address encryption of SF.HWProtect uses probabilistic or permutational effects and has to be included in the AVA_SOF analysis with SOF-basic. Except for it, SF.HWProtect does not use probabilistic or permutational effects. 2. SF.LeakProtect The TOE Hardware protects against leakage of information from the IC. The protection features include: Functions designed to alter the power consumption of the device DES protection – the DES coprocessor contains additional measures to resist side- channel attacks. SF.LeakProtect uses probabilistic or permutational effects and has to be included in the AVA_SOF analysis with SOF-basic. 3. SF.RNG The TOE includes a physical random number generator (HW RNG) designed to produce random numbers for the generation of cryptographic keys and for other critical uses. This random number generator meets the requirements of application class P2 (as specified in [AIS31]). The TOE can be used to generate 16-bit random numbers which satisfy the requirements of the monobit, poker, runs, long run, and autocorrelation tests in [AIS31]. Application Notes The TOE provides a tamper resistant hardware random number generator (see section 9 of [HM]). SF.RNG uses probabilistic or permutational effects and has to be included in the AVA_SOF analysis with SOF-basic. 4. SF.DES The TOE provides a hardware DES coprocessor that carries out DES encryption and decryption in ECB mode according to the following standard: AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 42 of 56 a) U.S. Department of Commerce / National Bureau of Standards Data Encryption Standard, FIPS PUB 46-3, 1999 October 25. Application Notes 1. The DES coprocessor implements single DES encrypt and decrypt operations, and has been optimised to allow easy implementation of triple-DES (as described in the standard) in Smartcard Embedded Software, as described in section 13.3.2 of [HM]. 2. Although the TOE provides a DES coprocessor, DES is only actually used as an encryption function in the context of particular Smartcard Embedded Software. 3. The TOE implements ECB mode - software can implement other modes such as CBC. 4. To provide secure embedded software, the software developer is required to ensure that the DES and (where used in a cryptographic algorithm) modular multiplication coprocessors, are used in a way that does not compromise the key or plain text (see A.Plat-Appl, A.Resp-Appl and A.Key-Function). Guidance for the implementation of secure Smartcard Embedded Software is given in [UGM]. SF.DES uses probabilistic or permutational effects but does not need to be included in the AVA_SOF analysis with SOF-basic since the function is beyond the scope of a Common Criteria evaluation. 5. SF.FMU The TOE firewall management unit enables software to control addresses that can be accessed in the following two ways: a) The FMU checks that a target address used in any instruction is within the specified limits. If a target address is not within accessible areas then the TOE enters the reset state. b) In addition, the FMU may enforce a policy that the TOE may not execute code in either EEPROM or RAM, or both. Changes to these policies can only be made by software executing in ROM. Application Notes: 1. The accessible address registers are defined in section 11.2 of [HM]. SF.FMU does not use probabilistic or permutational effects. 6. SF.ESFunctions The scope of the TOE evaluation includes correct operation of aspects such as the CPU instructions, memory functions and standard peripherals such as memories, registers, I/O interfaces, timers and UART as specified in [HM]. In addition, the TOE offers hardware facilities that are designed to enable Smartcard Embedded Software to address threats to its correct operation by taking control of the operating environment. The Smartcard Embedded AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 43 of 56 Software developer can rely on the following TOE functionality that has been specifically evaluated as part of the TOE: EWE Interrupt Every time the TOE writes to EEPROM, it generates a non-maskable interrupt (the EWE interrupt). When this interrupt occurs, execution is passed to a user-definable address held in the EWE vector. A user can therefore add code at this location to carry out a variety of checks, for example to confirm the integrity of data, or the context in which certain areas of EEPROM are being written. If a new EWE interrupt is received before the previous one has been cleared then the TOE enters the reset state. CPU Halt When the halt bit is set by user software, the TOE will stop execution until an external reset is received. SF.ESFunction does not use probabilistic or permutational effects. 7. SF.TestModeControl Once the TOE has been set to user mode, test mode functions are no longer accessible. SF.TestModeControl does not use probabilistic or permutational effects. 8. SF.EEPAccess The TOE allows any page of EEPROM to have writes (or erase) disallowed by setting the page to have a protected state. If a write (or erase) is attempted to a protected page then it will leave the page content unaltered. Protection of a page against writes is permanent once set. SF.EEPAccess does not use probabilistic or permutational effects. 9. SF.Inject During manufacture, each TOE is injected with data that uniquely identifies the individual IC. If specified for the Smartcard Embedded Software included, then additional data (some of it IC-specific) may also be injected during manufacture. SF.Inject does not use probabilistic or permutational effects. The Reset State The reset state is referred to in several of the Security Functions above. In the reset state, the chip stops execution until a reset signal is received on the reset line. When a reset occurs, the following actions are carried out: The CPU resets to its initial state Registers are set to their initial values (as defined in [HM]) AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 44 of 56 Execution begins at the location in the reset vector (as defined in [HM]). HW.MMCopro The TOE provides a coprocessor that carries out modular multiplication according to the specification as in section 3 of [HM]. This forms the basis for software implementation of algorithms such as RSA. HW.MMCopro refers to a critical function of the IC, but it is not specifically evaluated as a security function because the TOE provides generic modular arithmetic functionality, rather than a specific cryptographic function such as RSA encryption or signature. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 45 of 56 6.2 Correspondence Between TOE Security Function and SFR Table below shows the correspondence between SFRs and each of the Security Functions provided in the section 6.1 above. Table 6-1: TOE Security Functions Mapping to SFRs TOE Security Function SFR SF.HWProtect, FRU_FLT.2, FPT_FLS.1, FPT_SEP.1, FPT_PHP.3 SF.LeakProtect FDP_ITT.1, FPT_ITT.1, FDP_IFC.1 SF.RNG FCS_RND.1 SF.DES FCS_COP.1 [DES] SF.FMU FRU_FLT.2, FPT_FLS.1, FPT_SEP.1, FPT_PHP.3, FDP_ACC.1 [CRP], FDP_ACF.1 [CRP] SF.ESFunctions, FRU_FLT.2, FPT_FLS.1, FPT_SEP.1, FPT_PHP.3 SF.TestModeControl FMT_LIM.1, FMT_LIM.2 SF.EEPAccess FPT_FLS.1, FPT_SEP.1, FDP_ACC.1 [WPP], FDP_ACF.1 [WPP] SF.Inject FAU_SAS.1 6.3 Assurance Measures The TOE meets the requirements for EAL4 (as defined in [CC/3]) The table below maps assurance requirements to the documents describing the relevant requirements: AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 46 of 56 Table 6-2: Documents Meeting Assurance Requirements Document [CC/3] Evidence Item Related Assurance Components Security Policy Model ADV_SPM Security Policy Model Security Function ADV_FSP Functional Specification ADV_FSP Hardware Manual User Guidance and administrator guidance documentation AGD_USR, AGD_ADM User Guidance Manual User Guidance and administrator guidance documentation AGD_USR, AGD_ADM ADO_IGS Correspondence Mapping Correspondence analysis between TOE Summary Specification and functional specification, high level design, low level design and implementation ADV_RCR High-Level and Low-Level Design Documentation Set High-level design, low-level design ADV_HLD, ADV_LLD Source Code* Implementation ADV_IMP Test Documentation Set Testing, test depth and test coverage documentation ATE Development tools documentation ALC Configuration management documentation ACM Site Information Delivery procedures ADO_DEL Misuse Analysis Misuse Analysis AVA_MSU Strength of Function Analysis Strength of Function Analysis AVA_SOF Vulnerability Analysis Vulnerability Analysis AVA_VLA Note: The source code exists in an electronic data form. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 47 of 56 7. PP Claims There is no PP to which this ST conforms. 7.1 PP Reference This ST refers to [BSI-PP-0002] to decide SFRs. Note that [PA] is used to define additional requirements relating to cryptographic functions. This ST also refers to [PA]. 7.2 PP Tailoring FCS_RND.1 is completed with a quality metric – see section 5.1.1.6. 7.3 PP Additions The inclusions from [BSI-PP-0002] are clearly shown in the relevant section titles. All other assumptions, threats, objectives and SFRs, in sections 3.2.2, 3.2.3, 3.3.2, 3.4.2, 4.1.2, 4.1.3, 4.2.2, 5.1.2, 5.1.3, 5.2.1, and 5.2.2.2 are additional to those in the PP. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 48 of 56 8. Rationale 8.1 Security Objectives Rationale The way in which [BSI-PP-0002] assumptions, organisational security policy and threats are met by objectives is given in section 7.1 of [BSI-PP-0002]. The table below includes the mapping from section 7.1 of [BSI-PP-0002] and adds the rationale for the additional assumptions, policy and threats in this Security Target. Table 8-1: Coverage of Security Assumptions, Policies and Threats by Objectives Assumption/Threat/ Organisational Security Policy Addressed by Objective A.Key-Function OE.Plat-Appl, OE.Resp-Appl A.Plat-Appl OE.Plat-Appl A.Process-Card OE.Process-Card A.Resp-Appl OE.Resp-Appl A.InjDatSupp OE.InjDatSupp P.Add-Functions O.Add-Functions P.Process-TOE OE.Process-TOE, O.Identification T.Leak-Inherent O.Leak-Inherent T.Phys-Probing O.Phys-Probing T.Phys-Manipulation O.Phys-Manipulation T.Malfunction O.Malfunction T.Leak-Forced O.Leak-Forced T.Abuse-Func O.Abuse-Func T.NoSWDetect O.SWDetect T.NoSWResponse O.SWResponse T.RND O.RND A.Key-Function is enforced by OE.Plat-Appl and OE.Resp-Appl, which directly requires the embedded software to use the features in TOE documentation to take measures to ensure that keys are not compromised by the way in which the TOE’s cryptographic functions are used. Note that this recognises the fact that measures in hardware are only part of the solution for software TOEs, which must also ensure that their algorithms protect keys. A.Plat-Appl is enforced by a directly corresponding requirement on the environment in OE.Plat- Appl. (Note that as in section 7.1 of [BSI-PP-0002], this applies to Phase 1 of the lifecycle.) A.Process-Card is enforced by a directly corresponding requirement on the environment in OE.Process-Card. (Note that as in section 7.1 of [BSI-PP-0002] this applies to Phases 4-6 of the lifecycle.) A.Resp-Appl is enforced by a directly corresponding requirement on the environment in OE.Resp-Appl. (Note that as in section 7.1 of [BSI-PP-0002] this applies to Phase 1 of the lifecycle.) A.InjDatSupp is enforced by a directly corresponding requirement on the environment in OE.InjDatSupp. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 49 of 56 OE.Process-TOE requires the TOE Manufacturer to implement those measures assumed in P.Process-TOE. Therefore, the organisational security policy is covered by this objective, as far as organisational measures are concerned. The only issue not completely covered by these measures is the fact that the TOE has to support the possibility of unique identification. This is the content of O.Identification. Therefore, the organisational security policy is covered by OE.Process-Card and O.Identification. (Note that as in section 7.1 of [BSI-PP-0002] this applies to Phases 2-3 of the lifecycle.) The basic rationale for T.Leak-Inherent, T.Phys-Probing, T.Phys-Manipulation, T.Malfunction, T.Leak-Forced, and T.Abuse-Func is given in section 7.1 of [BSI-PP-0002]: for all threats the corresponding objectives O.Leak-Inherent, O.Phys-Probing, O.Phys-Manipulation, O.Malfunction, O.Leak-Forced, and O.Abuse-Func are stated in a way, which directly corresponds to the description of the threat. It is clear from the description of each objective, that the corresponding threat is removed if the objective is valid. More specifically, in every case the ability to use the attack method successfully is countered, if the objective holds. Since O.Add-Functions requires the TOE to implement exactly the same specific security functionality as required by P.Add-Functions, the organisational security policy is covered by the objective. The text below gives further rationale from [PA] Compared to [BSI-PP-0002] a clarification has been made for the security objective “Usage of Hardware Platform (OE.Plat-Appl)”: If required the Smartcard Embedded Software shall use these cryptographic services of the TOE and their interface as specified. In addition, the Smartcard Embedded Software must implement functions which perform operations on keys (if any) in such a manner that they do not disclose information about confidential data. This addition ensures that the assumption A.Plat-Appl is still covered by the objective OE.Plat-Appl although additional functions are being supported according to O.Add-Functions. Compared to [BSI-PP-0002] a clarification has been made for the security objective “Treatment of User Data (OE.Resp-Appl)”: By definition, encryption data, plain text data, and cryptographic keys are User Data. So, the Smartcard Embedded Software will protect such data if required, and the keys and functions are used appropriately in order to ensure the strength of cryptographic operation. Quality and confidentiality must be maintained for keys that are imported and/or derived from other keys. This implies that appropriate key management has to be realised in the environment. These measures make sure that the assumption A.Resp-Appl is still covered by the security objective OE.Resp-Appl although additional functions are being supported according to P.Add-Functions. The justification of the additional policy and the additional assumption show that they do not contradict to the rationale already given in [BSI-PP-0002] for the assumptions, policy and threats defined there. Smartcard Embedded Software may implement measures using the ability given by the TOE to embedded software to detect and respond to the results of attacks based on these threats, in O.SWDetect and O.SWResponse. This can help address some of the core threats – T.Phys- Manipulation, T.Malfunction and T.Abuse-Func by detecting the results of attempts to tamper with the operation of the IC, and using additional defensive measures at the level of the target of the attack7 . However, since no assumptions are made about the content of Smartcard Embedded 7 An attacker only stands to gain in a material sense if the applications themselves are attacked, since these represent the only assets that yield direct benefits to the attacker. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 50 of 56 Software (and hence the use made of these features), these objectives are not included for the core threats in the table above. T.NoSWDetect and T.NoSWResponse are directly addressed by O.SWDetect and O.SWResponse respectively. T.RND is addressed by O.RND. 8.2 Security Requirements Rationale The way in which [BSI-PP-0002] objectives are implemented by SFRs and requirements on the environment is given in section 7.2 of [BSI-PP-0002]. The table below includes the mapping from section 7.2 of [BSI-PP-0002] (but without the right most column “Security Requirements for the Environment”) and adds the rationale for the additional SFRs in this Security Target. Table 8-2: Coverage of Objectives by SFRs Objective Addressed by SFR O.Leak-Inherent FDP_ITT.1, FPT_ITT.1, FDP_IFC.1 O.Phys-Probing FPT_PHP.3 O.Phys-Manipulation FPT_PHP.3 O.Malfunction FRU_FLT.2, FPT_FLS.1, FPT_SEP.1 O.Leak-Forced FDP_ITT.1, FPT_ITT.1, FDP_IFC.1, FRU_FLT.2, FPT_FLS.1, FPT_SEP.1, FPT_PHP.3 O.Abuse-Func FMT_LIM.1, FMT_LIM.2, FDP_ITT.1, FPT_ITT.1, FDP_IFC.1, FPT_PHP.3, FRU_FLT.2, FPT_FLS.1, FPT_SEP.1 O.Identification FAU_SAS.1 O.RND FCS_RND.1, FDP_ITT.1, FPT_ITT.1, FDP_IFC.1, FPT_PHP.3, FRU_FLT.2, FPT_FLS.1, FPT_SEP.1 O.Add-Functions FCS_COP.1 [DES] AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 51 of 56 Objective Addressed by SFR O.SWDetect FPT_FLS.1, FDP_ACC.1 [CRP], FDP_ACC.1 [WPP], FDP_ACF.1 [CRP], FDP_ACF.1 [WPP] O.SWResponse FPT_FLS.1 OE.Resp-Appl FDP_ITC.1, FCS_CKM.1, FCS_CKM.4, FMT_MSA.2 Reference is made to section 7.2 of [BSI-PP-0002] for the basic rationale. The remainder of this section deals with the additional parts of the rationale introduced for this Security Target. It is noted that the features covered by FDP_ACC.1 and FDP_ACF.1 address potential physical manipulation and malfunction attacks because they constrain the ways in which execution can occur. Furthermore, these access control measures directly protect parameters controlling some of the other security measures provided under FPT_FLS.1 from external attacks (e.g. only Smartcard Embedded Software in ROM can set firewall management unit parameters, hence attacks based on changing these parameters in other conditions induced by attackers will be prevented). O.Phys-Manipulation and O.Malfunction can be further addressed by Smartcard Embedded Software by using the TOE’s features that allow embedded software to detect and respond to execution states that could represent attacks (included under FPT_FLS.1). However, this depends on the Smartcard Embedded Software and is therefore beyond the scope of the TOE. The DES requirement of O.Add-Functions is directly implemented by FCS_COP.1.1. Rationale for this is excerpted from [PA] as follows. The security functional requirement “Cryptographic operation (FCS_COP.1)” exactly requires those functions to be implemented which are demanded by O.Add-Functions. Therefore, FCS_COP.1 is suitable to meet the security objective. Nevertheless, the developer of the Smartcard Embedded Software must ensure that the additional functions are used as specified and that the User Data processed by these functions are protected as defined for the application context. These issues are addressed specifically by the security functional requirements specified below. [FDP_ITC.1 Import of user data without security attributes or FCS_CKM.1 Cryptographic key generation], FCS_CKM.4 Cryptographic key destruction, FMT_MSA.2 Secure security attributes. which will be fulfilled in the environment (addressed by the security environment objective OE.Resp-Appl), and the details are not known. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 52 of 56 The justification of the security objective O.Add-Functions and the additional requirements (both for the TOE and its environment) show that they do not contradict to the rationale already given in [BSI-PP-0002] for the assumptions, policy and threats defined there. O.SWDetect is implemented by the exception conditions recognised under FPT_FLS.1 and the opportunities provided to test for violations of secure state (or to maintain velocity check parameters) by the EEPROM write interrupts in FPT_FLS.1. As noted for O.Phys-Manipulation and O.Malfunction above, the access control provisions in FDP_ACC.1 and FDP_ACF.1 provide protection for the ways in which these detection features are used. O.SWResponse is implemented by the ability of Smartcard Embedded Software to cause a reset (by setting the halt bit to halt the processor, as noted under FPT_FLS.1), and the opportunity for other protective measures as part of the EWE interrupt routines provided under FPT_FLS.1. The assignment/selection operations performed on the SFRs drawn from [BSI-PP-0002] are shown in [BSI-PP-0002] itself. The additional operations performed in this ST are as follows: Table 8-3: Completion of SFRs SFR Operation required Operation performed FCS_RND.1 [assignment: a defined quality metric] The requirements of the monobit, poker, runs, long run, and autocorrelation tests in [AIS31]. [assignment: list of cryptographic operations] Encryption and decryption [assignment: cryptographic algorithm] DES [assignment: cryptographic key sizes] 56 bit FCS_COP.1 [DES] [assignment: list of standards] U.S. Department of Commerce / National Bureau of Standards Data Encryption Standard (DES), FIPS PUB 46-3, 1999 October 25 [assignment: access control SFP] Controlled-Register Policy FDP_ACC.1 [CRP] [assignment: list of subjects, objects, and operations among subjects and objects covered by the SFP]. Any attempt to set bits in defined, security-relevant registers [assignment: access control SFP] Write-Protect Policy FDP_ACC.1 [WPP] [assignment: list of subjects, objects, and operations among subjects and objects covered by the SFP]. Software to write to EEPROM. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 53 of 56 SFR Operation required Operation performed [assignment: access control SFP] Controlled-Register Policy [assignment: security attributes, named groups of security attributes] The memory area where the software is executed from, the memory area to be accessed and the operation to be performed [assignment: rules governing access among controlled subjects and controlled objects using controlled operations on controlled objects] Evaluate the corresponding permission control information: “The ability to set the values in the controlled registers is restricted to software operations executed from the ROM.” before, during or after the access so that accesses to be denied can not be utilised by the subject attempting to perform the operation [assignment: rules, based on security attributes, that explicitly authorise access of subjects to objects] None FDP_ACF.1 [CRP] [assignment: rules, based on security attributes, that explicitly deny access of subjects to objects] None [assignment: access control SFP] Write-Protect Policy [assignment: security attributes, named groups of security attributes] The memory area to be accessed and the operation to be performed [assignment: rules governing access among controlled subjects and controlled objects using controlled operations on controlled objects] Evaluate the corresponding permission control information: “An attempt to write to EEPROM shall fail, leaving the previous memory contents unaltered if protection is set for the relevant EEPROM page. Once a page is write- protected, this protection cannot be removed.” before, during or after the access so that accesses to be denied can not be utilised by the subject attempting to perform the operation [assignment: rules, based on security attributes, that explicitly authorise access of subjects to objects] None FDP_ACF.1 [WPP] [assignment: rules, based on security attributes, that explicitly deny access of subjects to objects] None 8.2.1 Dependencies The basic dependencies are shown in section 7.2.2 of [BSI-PP-0002] and are applicable to this ST – these are summarised in the table below: AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 54 of 56 Table 8-4: Dependencies from [BSI-PP-0002, 7.2.2] SFR Dependencies Fulfilled by Security Requirements in [BSI-PP-0002]? FRU_FLT.2 FPT_FLS.1 Yes FPT_FLS.1 ADV_SPM.1 Yes (Part of EAL4) FPT_SEP.1 None No dependency FMT_LIM.1 FMT_LIM.2 Yes FMT_LIM.2 FMT_LIM.1 Yes FAU_SAS.1 None No dependency FPT_PHP.3 None No dependency FDP_ITT.1 FDP_ACC.1 or FDP_IFC.1 Yes FDP_IFC.1 FDP_IFF.1 See discussion in [BSI-PP-0002, 7.2.2] FPT_ITT.1 None No dependency FCS_RND.1 None No dependency The additional dependencies relating to the new SFRs introduced in this ST are analysed below. Table 8-5: Additional SFR Dependencies SFR Dependencies Fulfilled by Security Requirements in this ST? FCS_COP.1 [DES] [FDP_ITC.1 or FCS_CKM.1] FCS_CKM.4 FMT_MSA.2 Yes (by the environment) FDP_ITC.1 [FDP_ACC.1, or FDP_IFC.1] FMT_MSA.3 No additional requirement – see discussion below FCS_CKM.1 FCS_CKM.4 FMT_MSA.2 No additional requirement – see discussion below FCS_CKM.4 [FDP_ITC.1 or FCS_CKM.1] FMT_MSA.2 No additional requirement – see discussion below FMT_MSA.2 ADV_SPM.1 [FDP_ACC.1 or FDP_IFC.1] FMT_MSA.1 FMT_SMR.1 No additional requirement – see discussion below FDP_ACC.1 [CRP] FDP_ACF.1 Yes FDP_ACC.1 [WPP] FDP_ACF.1 Yes FDP_ACC.1 Yes FDP_ACF.1 [CRP] FMT_MSA.3 No additional requirement – see discussion below FDP_ACC.1 Yes FDP_ACF.1 [WPP] FMT_MSA.3 No additional requirement – see discussion below The dependencies defined for FCS_COP.1 in [CC/2] are discharged by the requirements on the environment, as described in [PA]. Hence there is no further functional requirement on the TOE arising from the dependencies of FCS_COP.1. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 55 of 56 The dependencies defined for FDP_ITC.1, FCS_CKM.1, FCS_CKM.4, and FMT_MSA.2 are not resolved because they will be fulfilled in the environment, where the appropriate decisions will be made. The dependency defined for FDP_ACF.1 in [CC/2] is discharged as follows: FDP_ACF.1 [CRP] is simply applied for the control of the access to registers, and it does not require setting of the initial value of security attributes, which is required under FMT_MSA.3. Also, FDP_ACF.1 [WPP] simply covers the control of the access to the EEPROM, and it also does not require setting of the initial value of security attributes, which is required under FMT_MSA.3. Therefore, the dependency on the component FMT_MSA.3 is discharged. The discussion in sections 8.2 and 8.3, and the rationale in section 7.2 of [BSI-PP-0002], show how the security functional requirements support each other in meeting the security objectives of this ST. Together with the discussion of dependencies above this shows that the security functional requirements build a mutually supportive whole. 8.3 TOE Summary Specification Rationale The table below shows the ways in which the SFRs are implemented by TOE security functions. Table 8-6: SFR Mapping to TOE Security Functions SFR TOE Security Function FRU_FLT.2 SF.HWProtect, SF.FMU, SF.ESFunctions FPT_FLS.1 SF.HWProtect, SF.FMU, SF.ESFunctions, SF.EEPAccess FPT_SEP.1 SF.HWProtect, SF.FMU, SF.ESFunctions, SF.EEPAccess FMT_LIM.1 SF.TestModeControl FMT_LIM.2 SF.TestModeControl FAU_SAS.1 SF.Inject FPT_PHP.3 SF.HWProtect, SF.FMU, SF.ESFunctions FDP_ITT.1 SF.LeakProtect FPT_ITT.1 SF.LeakProtect FDP_IFC.1 SF.LeakProtect FCS_RND.1 SF.RNG FCS_COP.1 [DES] SF.DES FDP_ACC.1 [CRP] SF.FMU FDP_ACC.1 [WPP] SF.EEPAccess FDP_ACF.1 [CRP] SF.FMU FDP_ACF.1 [WPP] SF.EEPAccess Details of the TOE summary specification rationale are not given in this version of the Security Target. AE45X1-C Security Target –Public Version AE45X1C-CC-ST-0002 Revision 3.0, 11 July, 2006 Page 56 of 56 8.4 Assurance Requirements and Strength of Function Rationale The assurance level EAL4 is chosen since it provides evaluation of sufficient design detail and an independent vulnerability analysis and it allows the developer to attain a reasonably high assurance level in commercial area. The strength of function level chosen is SOF-basic. The TOE is intended to support sensitive applications and a strength of function level basic seems to be reasonably sufficient. SOF-basic is consistent with the vulnerability analysis level that has been specified (AVA_VLA.2). 8.5 Mutual Support and Internal Consistency The discussion of security functional requirements, TOE Summary Specification and assurance components in the sections above shows that mutual support and consistency are present for both groups of requirements. The arguments given for the adequacy of the assurance components for the TOE functionality also shows that the functional and assurance requirements support each other and that there are no inconsistencies between these groups. For the additional functionality included in O.Add-Functions, the security functional requirements required to meet the security objectives O.Leak-Inherent, O.Phys-Probing, O.Malfunction, O.Phys-Manipulation and O.Leak-Forced also protect the cryptographic algorithms implemented according to the security functional requirement FCS_COP.1. Therefore, these security functional requirements support the secure implementation and operation of FCS_COP.1. 8.6 PP Claims Rationale None ** End of Document **