AE450 Security Target – Public Version AE450-CC-ST-0002
Semiconductor & Integrated Circuits
Hitachi, Ltd.
Version 1.0
25 November, 2002
© Copyright 2002, Hitachi, Ltd. All rights reserved.
AE450 (HD651450) Version 01
Smartcard Security Target
(Public Version)
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page ii
Summary of Amendments
Version 1.0 25 November, 2002
• Public Version
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page iii
0 Preface
0.1 Objectives of Document
This document defines the Security Target for evaluation of the Hitachi AE450. It is intended
to comply with the BSI-PP-0002 Protection Profile (see [BSI-PP-0002]). Although no
evaluated conformance claim is made, it is also 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 AE450
• Developers of Smartcard Embedded Software to run on the AE450
• Evaluators and certifiers of the AE450.
0.4 Related Documents
[BSI-PP-0002] Smartcard IC Platform Protection Profile, Version 1.0, Eurosmart, July
2001
[BSI-RN] 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 Information Technology – Security techniques – Evaluation
criteria for IT security – Part 1: Introduction and general model
[CC/2] ISO/IEC 15408-2 Information Technology – Security techniques – Evaluation
criteria for IT security – Part 2: Security functional requirements
[CC/3] ISO/IEC 15408-3 Information Technology – Security techniques – Evaluation
criteria for IT security – Part 3: Security assurance requirements
Note: the combination of all 3 parts of ISO 15408 is also referred to in this
document as "Common Criteria" or "CC".
[CCF] Hitachi Single-Chip Microcomputer AE-4 Series AE460/450 (HD651460/450)
Current Control Functions, Rev. 2.2, Hitachi Ltd., 11 March 2002
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page iv
[HM] Hitachi Single-Chip Microcomputer AE-4 Series AE450 (HD651450) Hardware
Manual, Rev. 1.2, Hitachi Ltd., 1 July 2002
[Opt] Option List for Smart Card Microcomputer (for HD651450 [AE450]), Version
1.3, Hitachi Ltd., 22 August 2002
[PA] Smartcard Integrated Circuit Platform Augmentations, v1.0, Atmel, Hitachi
Europe, Infineon Technologies & Philips Semiconductors, 8 March 2002
[UGM] Guidelines for Using the AE450, Rev. 1.1, Hitachi Ltd., 22 August 2002
A reference of the form [REF, n] refers to section n of REF.
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.
DES Data Encryption Standard
DPA Differential Power Analysis
ECB Electronic Code Book. A mode of DES encryption.
EEPROM Electronically Erasable Programmable Read-Only Memory
Embedded Software Software held in the AE450, having been developed by users of the
AE450. 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page v
Term Meaning
The AE450 does not depend on such software, and Embedded
Software is not part of the TOE. However, hard-coded Embedded
Software will be included in the ROM of any issued AE450 at
manufacturing time.
Note that Embedded Software includes all software on an AE450
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 AE450 whenever an attempt is made to
write to EEPROM.
FMU Firewall Management Unit – a feature of the AE450 that limits the
memory areas available.
IC Integrated Circuit
IC Dedicated
Software
Software developed by Hitachi and embedded in the IC. (Adopted
from [BSI-PP-0002])
IC Dedicated Test
Software
Software developed by Hitachi for testing the AE450 during
manufacture. This software is part of the TOE, but is not available for
general use by operating systems, applications or users in phase 7 of
the lifecycle (see section 2.3).
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.
Option List A form supplied by Hitachi and filled in by an AE450 customer,
specifying various options for the manufacture of AE450 ICs for that
customer. The aspects of particular interest to this security target are:
• Selection of whether pre-personalisation data injection is required
• Selection of whether the watchdog timer should be active.
The options list also describes the content and structure of the
manufacturing identification data that Hitachi will inject (see section
2.4.2).
PP Protection Profile
RAM Random Access Memory
Reset state A state in which the AE450 does not execute instructions or engage
in input/output. The AE450 can only leave the reset state by receiving
an external reset (on the RES line), which results in re-initialisation of
all registers and the clearing of volatile memory.
See also section 6.1.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page vi
Term Meaning
RNG Random number generator
ROM Read-Only Memory
SFR Security Functional Requirement
Smartcard IC (as used in [BSI-PP-0002]) Composition of the TOE, the Smartcard
Embedded Software, User Data and the package (the smartcard
carrier).
ST Security Target
TOE Target of Evaluation
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 [BSI-PP-0002, 8.7]) 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 AE450 the TOE Manufacturer refers to Hitachi.
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.
UART Universal Asynchronous Receiver Transmitter – accordance with
ISO/IEC7816-3.
UDF An interrupt generated by the AE450 at regular intervals as part of the
operation of the Watchdog Timer (WDT).
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 AE450 mode of operation after TOE Delivery. The AE450 is set
to this mode just before delivery, which renders the IC dedicated test
software permanently unavailable.
WDT Watchdog Timer – a feature of the AE450 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page vii
Table of Contents
1. ST Introduction..............................................................................................................1
1.1 ST identification.................................................................................................1
1.2 ST Overview......................................................................................................1
1.3 CC Conformance Claim.....................................................................................2
2. TOE Description............................................................................................................3
2.1 AE450 Product Description...............................................................................3
2.1.1 Hardware................................................................................................4
2.1.2 Software.................................................................................................6
2.1.3 Documents .............................................................................................6
2.2 AE450 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 ..........................................................................................11
2.4.1 Development Environment..................................................................11
2.4.2 Injection of Manufacturing Identification and Secret Data .................12
3. TOE Security Environment..........................................................................................13
3.1 Assets...............................................................................................................13
3.2 Assumptions.....................................................................................................14
3.2.1 Assumptions from [BSI-PP-0002].......................................................14
3.2.2 Assumptions from [PA].......................................................................15
3.2.3 Other Assumptions...............................................................................15
3.3 Threats..............................................................................................................16
3.3.1 Threats defined in [BSI-PP-0002] .......................................................16
3.3.2 Other Threats .......................................................................................19
3.4 Organisational Security Policies......................................................................20
4. Security Objectives......................................................................................................22
4.1 TOE Security Objectives .................................................................................22
4.1.1 Objectives from [BSI-PP-0002]...........................................................22
4.1.2 Objectives based on [PA].....................................................................25
4.1.3 Other Objectives ..................................................................................25
4.2 Environment Security Objectives ....................................................................26
4.2.1 Environment Security Objectives from [BSI-PP-0002] ......................26
4.2.2 Other Environment Security Objectives..............................................28
5. IT Security Requirements ............................................................................................29
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page viii
5.1 TOE Security Requirements ............................................................................29
5.1.1 TOE Security Functional Requirements from [BSI-PP-0002] ............30
5.1.2 Security Functional Requirements based on [PA]...............................35
5.1.3 Other TOE Security Functional Requirements....................................36
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...................................37
5.2.2 Security Requirements for the Non-IT Environment...........................40
6. TOE Summary Specification.......................................................................................42
6.1 TOE Security Functions...................................................................................42
6.2 Assurance Measures.........................................................................................46
7. PP Claims.....................................................................................................................48
7.1 PP Reference....................................................................................................48
7.2 PP Tailoring .....................................................................................................48
7.3 PP Additions ....................................................................................................48
8. Rationale ......................................................................................................................49
8.1 Security Objectives Rationale..........................................................................49
8.2 Security Requirements Rationale.....................................................................51
8.2.1 Dependencies.......................................................................................54
8.3 TOE Summary Specification Rationale...........................................................57
8.4 Assurance Requirements and Strength of Function Rationale ........................58
8.5 Mutual Support and Internal Consistency........................................................58
8.6 PP Claims Rationale ........................................................................................58
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 1 of 58
1. ST Introduction
The ST aims to provide potential users of the AE450 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: AE450 (HD651450) Version 01 Smartcard Security Target – Public Version
Version: 1.0
Provided by: Hitachi, Ltd.
This Security Target applies to the Hitachi AE450 integrated circuit, version 01 (as defined in
detail in the configuration list for the evaluation).
This public version of the AE450 Security Target (also known as “ST-lite”) is abridged from
the evaluated version of the full Security Target (version 1.2) with the approval of the
Certification Body.
1.2 ST Overview
This document is the Security Target (ST) for the Hitachi AE450 integrated circuit (IC)
product, intended for use as a smart card IC. The Hitachi AE450 complies with the Eurosmart
Protection Profile developed by the Secure Semiconductor Vendor Group [BSI-PP-0002].
However, the AE450 also provides a number of additional security features that have been
based on a long history of assisting software developers to implement secure Smartcard
Embedded Software. These AE450-specific security features have been added to the ST.
The AE450 is ideally suited for high 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, secured production facilities
and secure handling during shipment to the customer) is constantly reviewed in order to
maximise the overall security package. The AE450 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, watchdog timer, DES engine and power analysis attack protection are all included
providing a strong on-chip hardware security structure.
Uniquely, Hitachi smartcard devices are fabricated using a MONOS (Metal Oxide Nitride
Oxide Silicon) EEPROM structure. MONOS advantages compared to standard EEPROM
structures are, high resistance to radiation disturbance, high reliability and endurance.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 2 of 58
The AE450 fulfills the requirements of Smart Card applications requiring large memory, high
security and high speed secure authentication, or data encryption or electronic signature.
Examples include: Public Key (PKI), WAP, m-commerce, digital signature, USIM/UMTS.
Where public key is a core requirement, a high speed coprocessor able to process arithmetical
data in a time frame that ensures a fast and free flowing application environment is required.
Applications such as Wireless Application Protocol (WAP) and 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 AE450 provides a significant increase in ROM for
program storage over previous devices whilst ensuring a balance of EEPROM for data
storage. The AE450 has FMU and other features available from day one.
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 Firewall management units (FMU) in order
to provide data integrity between applications.
1.3 CC Conformance Claim
This ST is compliant with [CC/1], [CC/2] and [CC/3].
Because the ST conforms to the BSI-PP-0002 PP, it includes extended functionality classes
defined in [BSI-PP-0002, 8]. The ST is therefore [BSI-PP-0002] conformant, [CC/2]
extended and [CC/3] conformant.
The Assurance level is EAL4 augmented (for augmentations see section 5.1.4).
The strength of function is SOF-High.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 3 of 58
2. TOE Description
2.1 AE450 Product Description
The Target of Evaluation (TOE) is the AE450 single-chip microcomputer unit, for use as a
smartcard integrated circuit. The TOE consists of the hardware shown in Figure 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 [BSI-PP-0002, 3.3].
A block diagram of the AE450 is shown in Figure 1 below:
Interval timer2
EEPROM (32kbyte + 512byte)
RAM (4kbyte)
ROM (128kbyte)
I/O Port
(UART)
AE4 CPU
System control logic
Security logic
Clock
generator
CLK
Address Bus
RES
VCC
VSS
I/O-1/IRQ
I/O-2/IRQ
Data Bus
DES coprocessor
WDT
RNG
FMU
Interval timer1
Figure 1: Internal block diagram of the AE450
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 4 of 58
The TOE configuration is summarised in the table below:
Item Type Item Version Form of delivery
Hardware AE450 (HD651450)
single-chip microcomputer
01 Wafer or packaged module (see
section 2.3)
Software Test ROM software 01 (defined
by hardware
version)
Included in AE450 test ROM
Software Random Number
Enhancement Software
Defined by
[UGM]
Code listed in User Guidance
Manual [UGM]
Document Hardware Manual [HM] See section
0.4
Hardcopy
Document Current Control Functions
[CCF]
See section
0.4
Hardcopy
Document User Guidance [UGM] See section
0.4
Hardcopy
2.1.1 Hardware
The AE450 is a single-chip microcomputer (MCU) based around the high-speed AE-4 CPU
core (derived from Hitachi’s widely used H8/300H general purpose core). As can be seen
from the block diagram in Figure 1, the MCU comprises the following major blocks in
addition to the CPU: ROM, RAM, EEPROM, random number generator (RNG), DES
coprocessor, UART, two interval timers, watchdog timer (WDT), firewall management unit
(FMU) and two I/O lines.
CPU: the AE450 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 Hitachi’s 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 × 8 or 16 × 16-bits)
• Signed or unsigned divide instruction (16 ÷ 8 or 32 ÷ 16-bits)
• Special EEPROM write instruction and high-speed block transfer instruction
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 5 of 58
Memory: the AE450 has a memory mapped architecture and allows the EEPROM to be used
for both data and program storage.
• ROM: 128kbytes
• RAM: 4 kbytes RAM
• EEPROM: 32.5 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 bits
RNG: this can generate 16-bit numbers for use by the User software. It is designed to be used
with additional user software, to ensure that the random numbers used are suitable for the
intended use. An example of such software is given in Hitachi’s Guidelines for using the
AE450 [UGM, 7].
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 highly 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 AE450 has two Interval timers. These issue an interrupt at user
determined intervals
WDT: the watchdog timer is a powerful tool to help the user software detect and respond to
unauthorised program execution
FMU: this memory management function monitors memory access permissions for the user
software and enables the limiting of program execution from RAM and EEPROM.
I/O: 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, form the electrical interface of the TOE.
UART: half-duplex asynchronous mode that conforms to the ISO/IEC standard 7816-3.
• In addition to the above, the IC incorporates specialised security logic to help to ensure
the correct operation of the TOE.
Some security features, such as watchdog timer or 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 6 of 58
leakage attacks such as DPA. The evaluation of the TOE assumes that all relevant user
selectable security functions, as detailed in Hitachi’s user documents, are enabled when
required to ensure the security of operation.
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 AE450 and guidance for its use are given in [HM], [CCF]
and [UGM].
2.1.2 Software
The TOE includes the following software:
• The IC Dedicated Test Software is only used for testing during IC production, and is
not available to users.
• The Random Number Enhancement Software is provided to ensure good quality
random numbers are obtained by Smartcard Embedded Software. To enable users to
deploy the software according to their own specific requirements, this software is
supplied as a listing in [UGM, 7]. Note that the use of this software to access random
numbers is part of the intended method of use of the TOE under certain conditions,
and it is therefore part of the evaluated configuration.
All other Smartcard Embedded Software (e.g. an operating system) is outside the scope of the
TOE. Smartcard Embedded Software to be stored in ROM is supplied to Hitachi by the
customer in a secure manner, and is then protected by Hitachi’s secure production
environment.
2.1.3 Documents
The AE450 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 AE450 in applications is given in the User Guidance Manual [UGM].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 7 of 58
2.2 AE450 Intended Usage
The AE450 is intended for use in a range of high security applications, including high speed
secure authentication, data encryption or electronic signature. Examples include: Public Key
Infrastructure (PKI), WAP, m-commerce, digital signature, and USIM/UMTS.
As noted in section 2.1.2, the TOE is intended to be used with the Random Number
Enhancement Software contained in [UGM, 7].
2.3 TOE Lifecycle
The design and manufacturing lifecycle for the AE450 is shown in Figure 2 (and in [BSI-PP-
0002, 8.1.1]). The TOE can be delivered either at the end of phase 3, or at the end of phase 4,
as shown in the figure.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 8 of 58
Phase 7
Phase 6
Phase 5
Smartcard IC
Database Construction
IC Photomask
Fabrication
IC Manufacturing
IC Testing &
Pre-personalisation
IC Packaging
Testing
Pre-personalisation
requirements
Phase 3
Phase 4
Smartcard Finishing Process
Testing
Testing
Personalisation
End of Life Process
Smartcard Product End-Usage
Phase 2
IC Dedicated Software
Phase 1
Pre-personalisation
requirements
Smartcard
Embedded Software
IC Design
IC sensitive information
Software, tools
Embedded Software
Pre-personalisation data
Legend:
* Optional component
Transfer within
trusted site
Trusted delivery and
verification procedure
Alternative
TOE
Delivery
points
Figure 2: Design and manufacturing lifecycle
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 9 of 58
The stages shown are as listed below. This Security Target addresses phases 2-3 in Figure 2.
When the TOE is delivered by Hitachi 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. Hitachi deliver information about the AE450
(such as [HM] and [CCF]) 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. 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 AE450 ROM mask is sent via a secure
delivery method from the software developer to Hitachi, and its secure handling is then
ensured by Hitachi. Similarly, pre-personalisation data is sent by a secure route to Hitachi
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 Hitachi is included within the
scope of this security target.
• Phase 2: IC design, IC Dedicated Software development, and mask fabrication – 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 masks used to manufacture the various IC layers are created from
the layout design during this phase; ROM masks for the Smartcard Embedded Software
in a particular instance of the AE450 are fabricated after receipt of the software from
phase 1.
The security of the development environments for the IC and its dedicated software,
along with the secure fabrication and handling of masks are primary concerns of this
security target.
• Phase 3: IC wafer manufacturing – in this phase, wafers containing AE450 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 security of manufacture, including handling of masks, 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 Hitachi 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.
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 10 of 58
• 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.
2.3.1 Test and User Modes
During manufacturing and production (phases 2-4), the AE450 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 AE450 is always in test mode
in phases 2 and 3. If TOE Delivery takes place at the end of phase 4, then the AE450 will be
in 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 AE450 may be delivered at the end of either phase 3 or phase 4, as
requested by the customer. In either case, the AE450 will be delivered in User Mode, and
Hitachi will apply secure delivery procedures for the transport of the TOE from Hitachi
premises.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 11 of 58
2.4 TOE Environments
2.4.1 Development Environment
Hitachi’s development environment for the AE450 has implemented security measures
specifically to ensure the security of the AE450 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 AE450 logical and physical design
• Testing of AE450 security functionality
• Confidentiality and integrity of IC Dedicated Software
• Confidentiality and integrity of customer ROM code and injection data (i.e. the
Smartcard Embedded Software for an instance of the AE450)
• Mask manufacture site
• Confidentiality and integrity of customer ROM code and mask
• Confidentiality and integrity of AE450 design and base masks
• Manufacturing sites
• Confidentiality and integrity of AE450 base masks
• Confidentiality and integrity of customer ROM mask
• Confidentiality and integrity of test software
• Confidentiality and integrity of injection data
• Production of authentic AE450 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 Hitachi and within the scope of evaluation. The security measures include IT security to
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 12 of 58
protect information stored on Hitachi 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. Hitachi's
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 Hitachi's 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 Hitachi’s business.
The security of the IC Dedicated 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 Hitachi, 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 AE450 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 is
shown in [Opt].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 13 of 58
3. TOE Security Environment
3.1 Assets
This section defines the primary and secondary assets to be protected by the TOE. [BSI-PP-
0002, 3.1] 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 (stored in ROM) – 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 (stored in RAM or EEPROM) – 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 assets 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 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.
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 14 of 58
Such information and the ability to perform manipulations assist in threatening the primary
assets.
Assets relating specifically to the Organisational Security Policy P.Process-TOE and
Assumption A.Process-Card are given in [BSI-PP-0002, 3.1].
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 Hitachi 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 [BSI-PP-0002,
3.1].
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 AE450 hardware manual [HM], current control
supplement [CCF] 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 are 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 AE450 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 [BSI-PP-0002, 8.2].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 15 of 58
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.
An example of the type of attack relevant to this assumption would be analysis of the power
consumption of the IC during the cryptographic operation (i.e. DPA).
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 AE450.
To assist embedded software developers to implement leak-resistant code, guidance on secure
software implementation is given in [UGM, 3].
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. It is assumed that the generation, distribution,
maintenance, and destruction of this data is adequately secure.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 16 of 58
3.3 Threats
3.3.1 Threats defined in [BSI-PP-0002]
This section adopts the threats to ICs defined in [BSI-PP-0002, 3.3].
The AE450 has the following high-level security concerns, as in [BSI-PP-0002, 3.3]:
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 high-level 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 [BSI-PP-0002, 3.3], and the example attack scenarios in [BSI-PP-0002, 8.3]. 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 17 of 58
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 AE450 circuit structures. 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 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 18 of 58
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.
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 AE450, 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 19 of 58
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 AE450 makes available facilities that are useful for embedded software to use in
addressing the threats that it may face. This introduces an additional high-level security
concern for the AE450:
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 TOE
cannot detect such attacks, then it cannot apply any countermeasures to
protect itself.
The AE450 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 access an invalid memory address
(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 undefined instruction code
(vi) Attempts to alter registers controlling the operation of the TOE.
2
The “software environment” is a term used to capture the definition of acceptable memory use for the software
system using the AE450. This would usually be at the level of operating system software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 20 of 58
For the purposes of this threat, an “invalid memory address” is one that is marked as
“Reserved” in the AE450 memory map ([CCF, 1.3]).
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
The following policy requirement is taken from [BSI-PP-0002, 3.4].
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 [BSI-PP-0002, 3.1].
Hitachi 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 21 of 58
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 AE450, by ensuring that an AE450 can be identified. Note that
procedural measures (including Hitachi’s secure delivery procedures) will generally be
required to ensure that AE450 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.
As an additional policy, the AE450 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.
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).
3
For example, a hash or digital signature over a known area of memory might be provided by software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 22 of 58
4. Security Objectives
4.1 TOE Security Objectives
4.1.1 Objectives from [BSI-PP-0002]
The AE450 shares the following high-level security considerations from [BSI-PP-0002, 4.1]:
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 high-level 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 AE450 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 23 of 58
• 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)
• 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 high
combination of complex 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 AE450 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 high
combination of complex 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 24 of 58
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
• 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 AE450 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 25 of 58
4.1.2 Objectives based on [PA]
This section includes an objective for the AE450 to provide a DES function, which is based
on O.Add-Functions in [PA].
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).
Note that to achieve an adequate strength of function for an application context, Smartcard
Embedded Software may require use of triple-DES. The AE450 enables this using repeated
application of the DES coprocessor – this is discussed in [HM, 13.3.2] and in section 5.1.2.1.
4.1.3 Other Objectives
The AE450 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 high-level 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 access an invalid memory address
(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 undefined instruction code
4
The “software environment” is a term used to capture the definition of acceptable memory use for the software
system using the AE450. This would usually be at the level of operating system software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 26 of 58
(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 AE450 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.
4.2 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 AE450 hardware manual [HM], current control supplement
[CCF] and the TOE application notes
(ii) Findings of the TOE evaluation reports relevant to the
Smartcard Embedded Software.
Because the AE450 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)“.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 27 of 58
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 AE450 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 beyond practicality 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 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 28 of 58
Assets relating specifically to the Organisational Security Policy P.Process-TOE (which is the
source of this objective) are given in [BSI-PP-0002, 3.1].
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 [BSI-PP-0002, 3.1].
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.
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.
Hitachi ensures a secure interface with suppliers of this data by using the injection approach
in section 2.4.2. Transmission of data to Hitachi 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 Hitachi environment according to the medium.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 29 of 58
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
• AE450 features Some SFRs introduced from [BSI-PP-0002] are given a wider scope to
reflect additional security features of the AE450 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 AE450,
support to embedded software to run tests at certain points during
execution (enabling measures such as state integrity tests) and the
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 30 of 58
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] is added to represent the
way in which some AE450 registers are protected against changes
other than from embedded software executing in ROM;
FDP_ACC.1 [WPP] specifies 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 [BSI-PP-0002, 8].
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 AE450.
5.1.1.1 Operating Conditions
The AE450 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
Erroneous software conditions (some of which could arise from corruptions due to operating
conditions) are dealt with under FPT_FLS.1.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 31 of 58
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
Refinement: The term “failure” above means “circumstances”. The TOE prevents failures
for the “circumstances” defined above.
FRU_FLT.2 thus states the condition for normal secure operation of the AE450 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
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 AE450.
Refinement 2: The term “failure” above also covers the following types of failure:
(i) Attempts to access memory outside an area defined for the
software being executed
(ii) Attempts to access an invalid memory address
(iii) Attempts to execute code from a type of memory not permitted
by the software environment5
5
The “software environment” is a term used to capture the definition of acceptable memory use for the software
system using the AE450. This would usually be at the level of operating system software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 32 of 58
(iv) Attempts to execute an undefined instruction code
(v) Processor halted by Smartcard Embedded Software
Application notes:
1. The AE450 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.
Dependencies: No dependencies.
Refinement: The components supporting 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 AE450 controls access to test mode. Following [BSI-PP-0002], this is specified using the
extended functional family FMT_LIM, defined in [BSI-PP-0002, 8.5].
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 no substantial information
about construction of TSF to be gathered which may enable other attacks.
Dependencies: FMT_LIM.2.
Application notes:
1. The “capabilities” referred to in FMT_LIM.1 are the functions implemented in the IC
Dedicated Test Software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 33 of 58
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 no substantial information
about construction of TSF to be gathered which may enable other attacks.
Dependencies: FMT_LIM.1.
Application notes:
1. The “capabilities” referred to in FMT_LIM.2 are the functions implemented in the IC
Dedicated Test Software.
5.1.1.3 Storage of Production Data
The AE450 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 [BSI-PP-0002, 8.6].
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 34 of 58
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
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 35 of 58
This requirement is analogous to FDP_ITT.1 above but refers to TSF data
instead of User Data. Therefore, it should be understood 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 AE450 generates random numbers that can be used for cryptographic key generation. To
capture the functional requirement, the family FCS_RND, defined in [BSI-PP-0002, 8.4] is
used.
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 the
autocorrelation tests in [BSI-RN].
5.1.2 Security Functional Requirements based on [PA]
5.1.2.1 Cryptographic Support
The AE450 provides a DES coprocessor, which can be used to implement single or triple
DES.
FCS_COP.1 Cryptographic operation
Hierarchical to: No other components
DES Encryption and Decryption
FCS_COP.1.1 The TSF shall perform encryption and decryption in accordance with
a specified cryptographic algorithm Data Encryption Standard (DES)
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 36 of 58
and cryptographic key sizes of 56 bit that meet the following list of
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 note:
1. Although the AE450 provides a DES coprocessor, DES is only ever used as an encryption
function in the context of particular Smartcard Embedded Software, and for this reason it
is noted that application software may need to use triple DES to achieve a suitable
strength. In this case, Smartcard Embedded Software shall use the TOE to implement
triple DES, as described in the guidance for software developers in [HM, 13.3.2].
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 attempts to write to certain
controlled registers (FDP_ACC.1 [CRP]) and attempts to write to protected pages of
EEPROM memory (FDP_ACC.1 [WPP]).
Hierarchical to: No other components
FDP_ACC.1 [CRP]
The TSF shall enforce the Controlled-Register Policy on any attempt
to set bits in defined, security-relevant registers.
Controlled-Register Policy The ability to set the values in the controlled registers is
restricted to software instructions executed in ROM.
Application Notes:
1. The controlled registers are those defined in FDP_ACC.1.1.
FDP_ACC.1 [WPP]
The TSF shall enforce the Write-Protect Policy on any attempt to
write to EEPROM.
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 37 of 58
Once a page is write-protected, this protection cannot be
removed.
Dependencies: FDP_ACF.1 Security attribute based access control
Application Notes:
1. The setting of write protection is described in [HM, 8.5].
2. All modes of EEPROM write (see [HM, 8.4]) are covered by this policy.
5.1.4 TOE Security Assurance Requirements
The assurance level for this Security Target is EAL4 augmented, as in [BSI-PP-0002, 5.1.2].
The augmentations to EAL4 are:
• ADV_IMP.2 - this adds the full implementation representation of the security functions to
the evaluation scope
• ALC_DVS.2 - this increases the confidence in the vital area of developer security
measures to the highest CC level
• AVA_MSU.3 - this adds evaluator testing of the potential for misconfiguration of the
TOE within the evaluation scope
• AVA_VLA.4 - this increases the scope of vulnerability analysis and penetration testing to
the highest CC level.
The minimum strength of function is SOF-High. This is applicable to the output of the
random number generator, using the enhancement software (given in [UGM]), as in SF.RNG.
In addition, the quality of the mechanism contributing to the DPA resistance of the DES
coprocessor can be analysed using probabilistic methods based on measurement of the power
consumption of the TOE - SOF-High is also claimed for this mechanism.
Refinements of the assurance requirements required by [BSI-PP-0002], and implemented by
Hitachi for the AE450, are described in [BSI-PP-0002, 5.1.3].
5.2 Security Requirements for the Environment
5.2.1 Security Requirements for the IT Environment
In [BSI-PP-0002, 5.2.1], 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 on the environment are adopted from [PA].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 38 of 58
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.
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 operations are deliberately uncompleted and
dependencies 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 39 of 58
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
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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 40 of 58
5.2.2 Security Requirements for the Non-IT Environment
As in [BSI-PP-0002, 5.2.2], 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 AE450 hardware manual [HM], current control supplement
[CCF] and the hardware application notes
(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).
[BSI-PP-0002, 8.2.2] gives examples of ways in which Smartcard Embedded Software may
implement security issues. The AE450 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 AE450 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 Watchdog
Timer and EWE interrupt – cf. FPT_FLS.1 in section 5.1.1.1 and SF.ESFunctions in section
6.1.
For implementation of cryptographic functions in Smartcard Embedded Software, the
following requirement 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 41 of 58
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 when 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 42 of 58
6. TOE Summary Specification
6.1 TOE Security Functions
1. SF.HWProtect
The AE450 is protected from attacks on the operation of the IC hardware. The protection
features include detection of out-of-range supply voltages or frequencies, illegal address
or instruction, scrambling of the memory arrays and physical shielding of the die.
Detection of an error causes the AE450 to enter a reset state.
Correct operating ranges are defined in [HM] and [CCF].
2. SF.LeakProtect
The AE450 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 DPA
attacks
3. SF.RNG
The AE450 includes a physical random number generator 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 [BSI-
RN]).
The AE450 can be used to generate 16-bit random numbers which satisfy the
requirements of the monobit, poker, runs, long run and autocorrelation tests in [BSI-RN]:
Application Notes
1. The AE450 provides a hardware random number generator as in [HM, 9]. However,
to provide enhanced resistance to certain attacks, this Security Target requires use of
the software random number generation function at its slowest speed and using
software such as that described in [UGM, 7].
2. The AE450 provides a tamper resistant hardware random number generator [HM, 9].
However, in order to provide additional assurance to the User software that the
hardware is functioning, this [BSI-RN] requires the use of an on-line test of the RNG.
A suitable test routine is given in [UGM, 6].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 43 of 58
4. SF.DES
The AE450 provides a DES coprocessor that carries out DES encryption and decryption
in ECB mode, according to the following standard:
a) U.S. Department of Commerce / National Bureau of Standards Data Encryption
Standard, FIPS PUB 46-3, 1999 October 25.
Application Notes
1. The AE450 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 [HM, 13.3.2].
2. Although the AE450 provides a DES coprocessor, DES is only actually used
as an encryption function in the context of particular Smartcard Embedded
Software For some application contexts, triple DES (as described in [HM,
13.3.2]) may be required in order to achieve a suitable strength of function if
the Smartcard Embedded Software is to be evaluated6
– this is a matter for the
Smartcard Embedded Software security target.
3. The AE450 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 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, 3.6.1].
5. SF.FMU
The AE450 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 specified
limits.
If a target address is not within the limits then the AE450 enters the reset state.
b) In addition, the FMU may enforce a policy that the AE450 may not execute code
in either EEPROM or RAM, or both.
Changes to these policies can only be made by software executing in ROM.
6
Although strength of cryptographic functions is beyond the scope of a Common Criteria evaluation, triple DES
would probably be required to achieve SoF-High for Smartcard Embedded Software.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 44 of 58
Application Note:
1. The accessible address registers are defined in [HM, 11.2].
6. SF.ESFunctions
The scope of the AE450 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 AE450 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 Software developer can rely on the following AE450 functionality
that has been specifically evaluated as part of the TOE:
a) EWE Interrupt
Every time the AE450 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 AE450 enters the reset state.
b) Watchdog Timer
At software-defined intervals, the AE450 generates a non-maskable interrupt (the
UDF interrupt), and transfers control to a user-specified address held in the UDF
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.
The UDF interrupt interval can only be set by software executing in ROM (see
[HM, 10.2.3]).
If either a second UDF interrupt or an EWE interrupt (cf. SF.ESFunctions) is
received before the previous one has been cleared then the AE450 enters the reset
state.
c) CPU Halt
When the Halt bit is set by user software, the AE450 will stop execution until an
external reset is received.
Application Note
1. As noted in [UGM, 3.8.1], when ordering ICs, the watchdog timer needs to be
selected using [Opt].
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 45 of 58
7. SF.TestModeControl
Once the AE450 has been set to user mode, test mode functions are no longer accessible.
8. SF.EEPAccess
The AE450 allows any page of EEPROM to have writes (or erase) disallowed by setting
the page to have a protected state. If a write is attempted to a protected page then it will
leave the page content unaltered.
Protection of a page against writes is permanent once set.
9. SF.Inject
During manufacture, each AE450 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.
The Reset state
The reset state is referred to in several of the Security Functions above. In the reset state, the
AE450 stops execution until an external reset signal is received on the RES line. When an
external 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])
• execution begins at the location in the reset vector (as defined in [HM]).
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 46 of 58
6.2 Assurance Measures
The AE450 meets the requirements for EAL4 (as defined in [CC/3]) and the following
augmentations:
• ADV_IMP.2
• ALC_DVS.2
• AVA_MSU.3
• AVA_VLA.4
It also meets the requirements of the refinements made to the assurance requirements in [BSI-
PP-0002, 5.1.3].
The table below maps assurance requirements to the documents describing the relevant
requirements:
Document [CC/3] evidence item Related assurance
components
Security Function
Overview
Security Function
Functional Specification
ADV_FSP
Hardware Manual
User Guidelines
User Guidance AGD_USR
Correspondence analysis between TOE
Summary Specification and functional
specification, high level design, low
level design and implementation
ADV_RCR
Correspondence
Mapping
Security Policy Model ADV_SPM
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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 47 of 58
Document [CC/3] evidence item Related assurance
components
Site Procedures,
Life Cycle Support
Product Flow
Summary,
Development
Security, Tools
List
Development tools documentation ALC, ADO_IGS
Configuration
Management
Summary
Configuration management
documentation
ACM
Delivery
Procedures
Delivery procedures ADO_DEL
No document
required
Administrator guidance documentation AGD_AGM
Misuse Analysis Misuse Analysis AVA_MSU
Strength of
Function Analysis
Strength of Function Analysis AVA_SOF
Vulnerability
Analysis
Vulnerability Analysis AVA_VLA
Table 1: Documents meeting assurance requirements
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 48 of 58
7. PP Claims
7.1 PP Reference
This ST conforms to [BSI-PP-0002].
Note that [PA] is used to define additional requirements relating to cryptographic functions.
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, 4.1.2, 4.1.3, 4.2.2,
5.1.2, and 5.1.3, are additional to those in the PP.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 49 of 58
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 [BSI-PP-0002, 7.1]. The table below includes the mapping from
[BSI-PP-0002, 7.1] and adds the rationale for the additional assumptions, policy and threats
in this Security Target.
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
Table 2: Coverage of security assumptions, policies and threats by objectives
A.Key-Function is enforced by OE.Plat-Appl and OE.Resp-Appl, which directly requires the
embedded software to use the features in AE450 documentation (including, for example, the
DPA countermeasures noted in [CCF]) 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 [BSI-PP-0002, 7.1] 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 [BSI-PP-0002, 7.1] this applies to Phases 4-6 of the
lifecycle.)
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 50 of 58
A.Resp-Appl is enforced by a directly corresponding requirement on the environment in
OE.Resp-Appl. (Note that as in [BSI-PP-0002, 7.1] this applies to Phase 1 of the lifecycle.)
A.InjDatSupp is enforced by a directly corresponding requirement on the environment in
OE.InjDatSupp.
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 [BSI-PP-0002, 7.1] 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 [BSI-PP-0002, 7.1]: 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 cipher or plain text data and
cryptographic keys are User Data. So, the Smartcard Embedded Software will protect such
data if required and use keys and functions 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 the Protection Profile for the assumptions, policy
and threats defined there. Smartcard Embedded Software may implement measures using the
ability given by the AE450 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
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 51 of 58
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 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.
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 [BSI-PP-0002, 7.2]. The table below includes the mapping from
[BSI-PP-0002, 7.2] and adds the rationale for the additional SFRs in this Security Target.
Objective Addressed by SFR Security Requirements
for the Environment
O.Leak-Inherent FDP_ITT.1,
FPT_ITT.1,
FDP_IFC.1
RE.Phase-1
O.Phys-Probing FPT_PHP.3 RE.Phase-1
O.Phys-Manipulation FPT_PHP.3 RE.Phase-1
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
RE.Phase-1
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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 52 of 58
Objective Addressed by SFR Security Requirements
for the Environment
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
RE.Phase-1
O.Add-Functions FCS_COP.1 RE.Phase-1
RE.Cipher
O.SWDetect FPT_FLS.1,
FDP_ACC.1 [CRP],
FDP_ACC.1 [WPP]
O.SWResponse FPT_FLS.1
OE.Plat-Appl RE.Phase-1
OE.Process-TOE FAU_SAS.1
OE.Process-Card RE.Process-Card,
possibly supported by
RE.Phase-1
OE.Resp-Appl FDP_ITC.1,
FCS_CKM.4,
FMT_MSA.2
RE.Phase-1
Table 3: Coverage of objectives by SFRs
Reference is made to [BSI-PP-0002, 7.2] 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 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 watchdog timer and firewall management
unit parameters, hence attacks based on changing these parameters in other conditions
induced by attackers will be prevented).
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 53 of 58
O.Phys-Manipulation and O.Malfunction can be further addressed by Smartcard Embedded
Software by using the AE450’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.
Additional security requirements on the environment, relating to the use of this functionality,
are included in RE.Phase-1 and RE.Cipher. Rationale for this is taken from [PA] as follows.
The security functional requirement “Cryptographic operation (FCS_COP.1)” exactly require
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 by the
requirement RE.Phase-1 and more specifically by the security functional requirements
• [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 and the details are not known.
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 define
how to implement the specific security functionality. However, key-dependent functions
could be implemented in the Smartcard Embedded Software. In this case RE.Cipher requires
that these functions ensure that confidential data (User Data) can not be disclosed while they
are just being processed by the Smartcard Embedded Software. Therefore, with respect to the
Smartcard Embedded Software the issues addressed by the objectives just mentioned are
addressed by the requirement RE.Cipher.
The use of cryptographic algorithms requires use of appropriate keys - otherwise they do not
provide security. The requirement RE.Cipher addresses these specific issues since
cryptographic keys and other data are provided by the Smartcard Embedded Software.
RE.Cipher requires that keys must be kept confidential. They must be unique with a very
high probability, cryptographically strong etc. If keys are imported into the TOE (usually
after TOE Delivery), it must be ensured that quality and confidentiality is maintained.
Therefore, with respect to the environment the issues addressed (i) by the objectives just
mentioned and (ii) implicitly by O.Add-Functions, are addressed by the requirement
RE.Cipher.
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 the Protection Profile for the assumptions, policy and threats defined there.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 54 of 58
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 watchdog timer and 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 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 Watchdog Timer and EWE interrupt
routines encompassed 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:
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 [BSI-RN]
FCS_COP.1 [assignment: list of
cryptographic operations]
Encryption and decryption
[assignment: cryptographic
algorithm]
DES
[assignment: cryptographic
key sizes]
56 bit
[assignment: list of standards] U.S. Department of Commerce /
National Bureau of Standards
Data Encryption Standard (DES),
FIPS PUB 46-3, 1999 October 25
FDP_ACC.1
[CRP]
[assignment: access control
SFP]
Controlled-Register Policy
[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
FDP_ACC.1
[WPP]
[assignment: access control
SFP]
Write-Protect Policy
[assignment: list of subjects,
objects, and operations among
subjects and objects covered by
the SFP].
Any attempt to write to EEPROM.
Table 4: Completion of SFRs
8.2.1 Dependencies
The basic dependencies are shown in [BSI-PP-0002, 7.2.2] and are applicable to this ST –
these are summarised in the table below:
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 55 of 58
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
Table 5: Dependencies from [BSI-PP-0002, 7.2.2]
The additional dependencies relating to the new SFRs introduced in this ST are analysed
below.
SFR Dependencies Fulfilled by Security
Requirements in this ST?
FCS_COP.1 [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.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 No additional requirement
– see discussion below
FDP_ACC.1
[WPP]
FDP_ACF.1 No additional requirement
– see discussion below
Table 6: Additional SFR dependencies
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 56 of 58
The dependencies defined for FCS_COP.1 in [CC/2] are discharged by requirements on the
environment, as in [PA].
Hence there is no further functional requirement on the TOE arising from the dependencies of
FCS_COP.1.
The dependencies defined for FDP_ITC.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_ACC.1 in [CC/2] is discharged as follows:
• FDP_ACF.1 (subset access control) is invoked because it is assumed in [CC/2] that
FDP_ACC.1 specifies the requirement for application of access control using rules
separately specified under FDP_ACF.1. However, once again the AE450 situation is
much simpler and the TOE simply applies certain simple and easily defined restrictions
on writing to certain registers (FDP_ACC.1 [CRP]) or EEPROM pages (FDP_ACC.1
[WPP]). Hence in this ST it is considered sufficient to define the rules as part of the SFR
itself.
The discussion in sections 8.2 and 8.3, and the rationale in [BSI-PP-0002, 7.2], 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.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 57 of 58
8.3 TOE Summary Specification Rationale
The table below shows the ways in which the SFRs are implemented by AE450 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,
SF.EEPAccess
FDP_ITT.1 SF.LeakProtect
FPT_ITT.1 SF.LeakProtect
FDP_IFC.1 SF.LeakProtect
FCS_RND.1 SF.RNG
FCS_COP.1 SF.DES
FDP_ACC.1 [CRP] SF.FMU,
SF.ESFunctions
FDP_ACC.1 [WPP] SF.EEPAccess
Table 7: SFR mapping to AE450 Security Functions
Details of the TOE summary specification rationale are not given in this version of the
Security Target.
AE450 Security Target – Public Version AE450-CC-ST-0002
Version 1.0, 25 November 2002 Page 58 of 58
8.4 Assurance Requirements and Strength of Function Rationale
This ST follows the rationale given in [BSI-PP-0002, 7.2.3] for the choice of EAL4,
assurance augmentations and the strength of function SOF-high.
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
This ST implements all of the requirements of [BSI-PP-0002] by inclusion (as shown in each
of the relevant sections), and hence no further rationale is required.
**End of Document**