Common Criteria for Information Technology Security Evaluation Protection Profile ecf ecf E v aluation et Certification França i s e Intersector Electronic Purse and Purchase Device Version 1.2 Issue February 1999 Registered at the French Certification Body under the number PP/9909 For any kind of request for comments, please e-mail at ssi20@calva.net This document is paginated from i to ii and from 1 to 70 ii Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page i of ii Table of contents Chapter 1 PP introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 PP Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 PP overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Chapter 2 TOE Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Product type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1.3 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.2 IT features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Chapter 3 TOE Security Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.1 Assets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.3 Threats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.4 Organisational Security policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Chapter 4 Security objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.1 Security objectives for the TOE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4.2 Security objectives for the environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Chapter 5 TOE security functional requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.1 Class FAU Security Audit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.1.1 FAU_GEN.1: Audit data generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 5.1.2 FAU_SAR.1: Audit review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.1.3 FAU_STG.1: Protected audit trail storage . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.2 Class FCO Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.2.1 FCO_NRO.2: Enforced proof of origin . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 5.2.2 FCO_NRR.2: Enforced proof of receipt . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 5.3 Class FCS Cryptographic support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.3.1 FCS_COP.1: Cryptographic operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.4 Class FDP: User data protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.4.1 FDP_ACC.2: Complete access control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5.4.2 FDP_ACF.1: Security attribute based access control . . . . . . . . . . . . . . . . . 28 5.4.3 FDP_DAU.1: Basic Data authentication . . . . . . . . . . . . . . . . . . . . . . . . . . 29 5.4.4 FDP_ETC.1: Export of user data without security attributes . . . . . . . . . . . 29 Table of contents Intersector Electronic Purse and Purchase Device Page ii of ii Version 1.2 February 1999 5.4.5 FDP_IFC.1: Subset information flow control . . . . . . . . . . . . . . . . . . . . . . . 30 5.4.6 FDP_IFF.1: Simple security attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5.4.7 FDP_ITC.1: Import of user data without security attributes . . . . . . . . . . . 30 5.4.8 FDP_SDI.1: Stored data integrity monitoring . . . . . . . . . . . . . . . . . . . . . . 31 5.5 Class FIA Identification and authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 5.5.1 FIA_UID.1: Timing of identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 5.5.2 FIA_UAU.1: Timing of authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 5.5.3 FIA_UAU.3: Unforgeable authentication . . . . . . . . . . . . . . . . . . . . . . . . . . 32 5.5.4 FIA_UAU.4: Single-use authentication mechanisms . . . . . . . . . . . . . . . . . 32 5.5.5 FIA_UAU.6: Re-authenticating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 5.6 Class FPT Protection of the TOE Security functions . . . . . . . . . . . . . . . . . . . . 33 5.6.1 FPT_FLS.1: Failure with preservation of secure state . . . . . . . . . . . . . . . . 33 5.6.2 FPT_PHP.2: Notification of physical attack . . . . . . . . . . . . . . . . . . . . . . . . 33 5.6.3 FPT_PHP.3: Resistance to physical attack . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.6.4 FPT_RCV.4: Function recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.6.5 FPT_RPL.1: Replay detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.6.6 FPT_RVM.1: Non-bypassability of the TSP . . . . . . . . . . . . . . . . . . . . . . . 35 5.6.7 FPT_SEP.1: TSF domain separation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Chapter 6 TOE security assurance requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 6.1 ADV_IMP.2 Implementation of the TSF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 6.2 ALC_DVS.2 Sufficiency of security measures . . . . . . . . . . . . . . . . . . . . . . . . 37 6.3 AVA_VLA.4 Highly resistant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Chapter 7 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.2 Security Objectives rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.2.1 Threats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 7.2.2 Organisational security policies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 7.2.3 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.3 Security requirements rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.3.1 Security functional requirements rationale . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.3.2 Security functional requirements dependencies . . . . . . . . . . . . . . . . . . . . . 62 7.3.3 Strength of function level rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 7.3.4 Security assurance requirements rationale . . . . . . . . . . . . . . . . . . . . . . . . . 65 7.3.5 Security requirements are mutually supportive and internally consistent . 67 Annex A Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 1 of 70 Chapter 1 PP introduction 1.1 PP Identification 1 A glossary of terms used in the PP is given in annex A. 1.2 PP overview 2 This Protection Profile conducted under the french IT Security Evaluation and Certification Scheme is the work of a group composed of the following entities: - Banque de France, - EUROSMART, - GIE Cartes Bancaires CB, - CNET, - SCSSI. 3 The intent of this Protection Profile is to specify functional and assurance requirements applicable to an Intersector Electronic Purse (IEP) and a Purchase Device (PD) used within an IEP system. 4 The goal of an IEP system consists of allowing electronic low value financial transactions without manipulating any coins nor bills. An IEP is supposed to be implemented in a smartcard. 5 A PD is a physical device installed at the Service Provider used to accept payment from an IEP in a Purchase Transaction. It may include a Secure Application Module (SAM), built on a integrated circuit module or not. In both cases, the Purchase Device shall provide the necessary security for purchase transactions and the collection process. Title: Intersector Electronic Purse and Purchase device Protection Profile, Version 1.2, February 1999. Registration: PP/9909 1 - PP introduction Intersector Electronic Purse and Purchase Device Page 2 of 70 Version 1.2 February 1999 6 The main objectives of this Protection Profile are: - to describe the Target of Evaluation (TOE), - to describe the security environment of the TOE including the assets to be protected and the threats to be countered by the TOE or its environment, the assumptions that are done and the organisational security policies that are used, - to describe the security objectives for the TOE and its supporting environment, - to specify the security requirements which includes the TOE IT functional requirements and the TOE IT assurance requirements, - to give a rationale for this PP. 7 The Assurance level for this PP is EAL 4 augmented. 8 A product compliant with this PP may also offer additional functionalities that are not covered by this PP such as: - purse-to-purse functionality, - off-line reload, - reimbursement functionality: the balance of the IEP is debited and the corresponding value is returned in one way or another to the purse holder, - currency exchange functionality, - self loading functionality. 9 The additional security requirements corresponding the functionalities described above will have to be defined in an appropriate Security Target. 1.3 References 10 This Protection Profile has been build on the following references: - [CC-1] Common Criteria for Information Technology security Evaluation Part 1: Introduction and general model CCIB-98-026, version 2.0 May 1998, - [CC-2] Common Criteria for Information Technology security Evaluation Part 2: Security Functional Requirements CCIB-98-027, version 2.0 May 1998, Intersector Electronic Purse and Purchase Device 1 - PP introduction February 1999 Version 1.2 Page 3 of 70 - [CC-2B] Common Criteria for Information Technology security Evaluation Part 2 annexes CCIB-98-027A, version 2.0 May 1998, - [CC-3] Common Criteria for Information Technology security Evaluation Part 3: Security Assurance Requirements CCIB-98-028, version 2.0 May 1998, - [PP/9806] Smartcard Integrated Circuit Protection Profile, Version 2.0, Issue September 1998, registered PP/9806, - [PP/9809] Smartcard integrated circuit with embedded software Protection Profile, Eurosmart Security Working group, Version 1.0 October 1998, registered PP/9809. 1 - PP introduction Intersector Electronic Purse and Purchase Device Page 4 of 70 Version 1.2 February 1999 12 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 5 of 70 Chapter 2 TOE Description 11 This part of the PP describes the TOE as an aid to the understanding of its security requirements and address the product type, the intended usage and the general IT features of the TOE. 2.1 Product type 2.1.1 Introduction 12 This PP is related to the transaction kernel at the level of the IEP inside an IEP system. The main goal of an IEP system is to allow Electronic Value (EV) financial transactions, using an IEP and a PD. 13 Electronic Value (EV) is the counterpart of funds received by the EV provider. It is defined by the identity of the EV provider, the currency denomination and the amount. IEP or PD receiving amounts in several transactions may aggregate them into a single EV amount, as long as this does not alter the balance of the EV provider. Conversely, the EV amount stored in a IEP may be broken up and dispensed in several transactions. 2 - TOE Description Intersector Electronic Purse and Purchase Device Page 6 of 70 Version 1.2 February 1999 2.1.2 Description 14 The TOE that is considered in this PP is overviewed by the following figure: Fig. 2.1 - TOE Overview 15 The TOE is composed of the IEP and the Purchase Device. IEP 16 The IEP consists of an Integrated Circuit (IC) with an embedded software that is compliant with the PP Smartcard Integrated Circuit with Embedded Software (the PP/9809 is compliant with the PP/9806). The IC could support other applications including other IEPs. The main characteristics of an IEP are that it is prepaid, reloadable and interacts with the other part of the TOE: the purchase device. It may be anonymous or not. To be fully operational the IEP needs information. The actual introduction of this information is out of scope of this PP. The fully operational IEP contains various parameters that can be updated by an administration device. E V p r o v i d e r d e v i c e / P u r s e p r o v i d e r h o s t / A d m i n i s t r a t i o n d e v i c e I E P P u r c h a s e d e v i c e 3 1 2 4 5 C a p t i o n : f u n c t i o n s a d r e s s e d b y t h i s P P T O E 1 l o a d 2 p u r c h a s e 3 c o l l e c t 4 l a s t p u r c h a s e c a n c e l l a t i o n 6 5 u p d a t e I E P p a r a m e t e r s 6 u p d a t e p u r c h a s e d e v i c e p a r a m e t e r s Intersector Electronic Purse and Purchase Device 2 - TOE Description February 1999 Version 1.2 Page 7 of 70 17 Towards the EV, an IEP is able to: - store its amount of EV, - indicate its amount of EV, - debit its amount of EV via purchase transaction, - credit its amount of EV via load or last purchase cancellation of the IEP transactions. Purchase device 18 A PD is a physical device installed at the Service Provider used to accept payment from an IEP in a Purchase Transaction. It may include a Secure Application Module (SAM), built on a integrated circuit module or not. In both cases, the Purchase Device shall provide the necessary security for purchase transactions and the collection process. The PD is the part of the terminal of a retailer or a server used for electronic payment. It contains various parameters updated by the administration device. 19 Towards the EV, the purchase device is able to: - store EV, - receive an amount of EV from an IEP via purchase transaction, - return an amount of EV to an IEP via last purchase cancellation transactions, - deliver stored EV via collect transaction. 2.1.3 Environment IEP system overview 20 IEP system is a payment system intended for low value off line financial transactions. The global functioning of the IEP system is based on two cycles: - a first one consisting in EV amount exchanges, - as an economic counterpart, a second one consisting in payment and service, 21 To simplify, these cycles can be summarised as following: - the purse holder gives funds (cash, credit cards, etc.) to the EV provider who loads his IEP with an equivalent amount of EV (load transaction), - the purse holder asks the service provider for a service and transfers EV from his IEP to the PD (purchase transaction), 2 - TOE Description Intersector Electronic Purse and Purchase Device Page 8 of 70 Version 1.2 February 1999 - the service provider asks the EV provider for cash or credit on its bank account (collection) in exchange for the EV. 22 The model proposed by this Protection Profile defines only one EV Provider: IEP systems with more than one EV provider may be modelized as many IEP systems that share purchase devices. Actors 23 The actors identified in an IEP system are overviewed in the following figure: Fig. 2.2 - Actors An entity may play the role of different actors in the IEP system. E V p r o v i d e r d e v i c e L o a d d e v i c e A c q u i r e r d e v i c e I E P P u r c h a s e d e v i c e T r a n s f e r d e v i c e A d m i n i s t r a t i o n d e v i c e L o a d a g e n t P u r s e h o l d e r S e r v i c e p r o v i d e r P u r s e p r o v i d e r A c q u i r e r E V p r o v i d e r T r a n s f e r f a c i l i t i e s p r o v i d e r A c t o r s C a p t i o n : Intersector Electronic Purse and Purchase Device 2 - TOE Description February 1999 Version 1.2 Page 9 of 70 Purse provider 24 A purse provider is fully responsible for the security of the IEP system. For example, he is responsible for the security of the IC itself and of the embedded software that can affect EV processing.The purse provider is also responsible for administration of IEP and PD such as applets load or parameters update. In order to handle the administration operations the purse provider operates one or more administration devices. Administration operations include security management. 25 Depending on business arrangements with the service provider, the purse provider could ask the acquirer to aggregate several EV amounts associated with that service provider into a single EV amount in order to simplify EV collect and settlement process. Purse holder 26 A purse holder is a person in possession of an IEP. Purse holders need to protect their IEP as if it is cash. Service provider 27 A service provider sells services for which he accepts payment by IEP. In order to handle the purchase transactions the service provider operates one or more purchase devices in which he stores EV until collection and other information for his own purposes, if needed. The service provider is responsible for the operational security of the purchase device he controls. 28 The service provider can only be collected by its Acquirer. Load agent 29 A load agent is a trusted agent of a EV provider, who executes the load transactions with the purse holder 's IEP on behalf of the EV provider, with EV created by the EV provider. It may also issue the IEP for the purse provider. In order to execute the load transaction the load agent operates a load device. 30 The load agent is responsible for the operational security of its part of the IEP system, and must protect the load devices he controls against unauthorised use. Acquirer 31 An acquirer is a trusted agent of the EV provider who is responsible for collecting EV and, if possible, flow traceability data, from purchase devices concerning purchase and purchase cancellation transactions. He is also responsible for transferring payment received from the EV provider to the service provider for settlement. In order to handle the collection transactions the acquirer operates one or more acquirer devices. 2 - TOE Description Intersector Electronic Purse and Purchase Device Page 10 of 70 Version 1.2 February 1999 EV provider 32 The EV provider guarantees the EV in IEP system. To this end, the EV provider: - creates and dispenses EV in exchange for funds received, - redeems collected EV and destroys it. 33 In order to handle these transactions, the EV provider operates one or more EV provider devices. 34 As a consequence of the EV provider guaranteeing for the EV in the IEP system, such an entity also defines the level of security required for the system to be protected against fraud. The purse provider is accountable to the EV provider for maintaining that level of security. 35 The management of the flow traceability data is under control of the EV provider. Transfer facilities provider 36 The transfer facilities provider is responsible to transfer EV. It is optional as a transfer device can be reduced to a simple electric cable in certain cases. The transfer device contains no security functionality and so will be omitted in the next pages of the Protection Profile. Intersector Electronic Purse and Purchase Device 2 - TOE Description February 1999 Version 1.2 Page 11 of 70 EV flow model Fig. 2.3 - EV flow 37 EV is transferred only between the secure components of the participants in the IEP system. As an example, the flow of EV may be described in figure 2.3. 38 During each transaction (load, purchase, collection, cancellation) the EV credited on the one hand should always be equal to the EV debited on the other hand (as stated before (§32), only the EV provider is able to create / destroy EV). In order to settle, payment and services must be used. 2.2 IT features 39 The TOE IT functionalities consist of the following functions: - load (1 of figure 2.1): the IEP is credited with an amount of EV created by the EV provider, via a load agent; the purse holder gives a corresponding amount of funds in turn (cf. “payment” of figure 2.3), E V p r o v i d e r d e v i c e L o a d D e v i c e I E P P u r c h a s e D e v i c e A c q u i r e r D e v i c e C a p t i o n : E V f l o w P a y m e n t S e r v i c e 2 - TOE Description Intersector Electronic Purse and Purchase Device Page 12 of 70 Version 1.2 February 1999 - purchase (2 of figure 2.1): the IEP is debited from an amount of EV while the purchase device receives the same amount of EV; the purse holder receives services in turn (cf. “service” of figure 2.3), - collect (3 of figure 2.1): one or several amounts of the EV corresponding to a set of payment transactions stored by a PD is delivered to the EV provider device via an acquirer device; the service provider receives in turn the corresponding amount of money (cf. “payment” of figure 2.3), - last purchase cancellation of the PD that has not been collected yet (4 of figure 2.1): an amount of EV is recredited to an IEP and returned by the purchase device. The considered purchase shall be the last purchase of the IEP, - update IEP parameters (5 of figure 2.1): internal IEP parameters are updated by the purse provider. Parameters that are addressed are, for instance, the expense limit per transaction, the transaction keys, - update PD parameters (6 of figure 2.1): internal purchase device parameters are updated by the purse provider. 20 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 13 of 70 Chapter 3 TOE Security Environment 40 This section describes the security aspects of the environment in which the TOE is intended to be used and addresses the description of the assets to be protected, the assumptions, the threats and the organisational security policies. 3.1 Assets 41 As the main objective of an IEP system is to preserve the EV flow, the assets that shall be protected are the following ones: - Electronic Value (EV), - Flow Traceability data, - IEP and PD parameters such as the maximum amount of EV per IEP. 42 All these assets have to be protected in terms of integrity. Assets contained by PD that are addressed by this PP shall be protected in the same way than those contained by the IEP. PD and IEP shall have the same level of security. 43 These assets are all considered as user data for the Target of Evaluation. 3.2 Assumptions 44 The following general assumptions are done concerning the TOE: A.AD It is assumed that the Acquirer Device has capabilities to enter a secure state when a failure occurs during a collect transaction, or in case of any abnormal, corrupted, forged or replayed transactions. A.LA It is assumed that the LD has capabilities to enter a secure state when a failure occurs during a load transaction. A. INDEP The functionality of LA and the functionality of PD are independent applications: a SP could also be a load agent but in this case the application shall maintain two separate domains LA and PD: the two functionalities LA and PD have to be completely independent. 3 - TOE Security Environment Intersector Electronic Purse and Purchase Device Page 14 of 70 Version 1.2 February 1999 3.3 Threats 45 The TOE as defined in chapter 2 is required to counter the threats described hereafter; a threat agent wishes to abuse the assets either by functional attacks, environmental manipulations, specific hardware manipulations or by any other types of attacks. Intersector Electronic Purse and Purchase Device 3 - TOE Security Environment February 1999 Version 1.2 Page 15 of 70 MONEY LAUNDERING USURPATION 46 Usurpation of identity of IEP system actors: - actors not authorized by EV provider could be introduced in the IEP system in order to perform EV transactions, - authorized actors could be used in the IEP system to play another role than those they are dedicated for. 47 This threat is divided into 8 threats: T.LAUND_MON Laundering of money in order to hide the real sources of the money. T.USP_LA_LD Usurpation of LA identity during a load transaction: an IEP is loaded with fraudulent EV by a fraudulent LD; it leads to EV creation and alters EV flow.a T.USP_IEP_LD Usurpation of IEP identity during a load transaction: a fraudulent IEP is loaded with EV by a LD ; it leads to EV loss or alters EV flow. T.USP_PP_EVP_PCH Usurpation of PP and EVP identity during a purchase transaction: fraudulent EV is introduced in the PD by a fraudulent IEP; it leads to EV creation. T.USP_PP_PCH_IEP Usurpation of PP identity during a purchase transaction: EV is introduced in the PD by a fraudulent IEP; it alters EV flow. T.USP_IEP_LPC Usurpation, during a last purchase cancellation transaction, of the IEP identity that has achieved the last purchase transaction: EV is debited from the PD by a fraudulent IEP; it alters EV flow. T.USP_PP_PCH_PD Usurpation of PP identity during a purchase transaction: EV is credited in a fraudulent PD; it leads to EV loss or it alters EV flow. T.USP_PP_EVP_LPC Usurpation of PP identity and EVP identity during a last purchase cancellation transaction: fraudulent EV is credited in an IEP by a fraudulent PD; it leads to EV creation. 3 - TOE Security Environment Intersector Electronic Purse and Purchase Device Page 16 of 70 Version 1.2 February 1999 REPLAY 48 Replay of a transaction. This type of threat is divided into 6 threats: a. It is understood as altering the EV flow model and then the traceability data. T.USP_PP_EVP_CLT Usurpation of PP identity and EVP identity during a collect transaction: fraudulent EV is collected from a fraudulent PD by an AD; it leads to EV creation. T.USP_A_CLT Usurpation of A identity during a collect transaction: EV is collected from the PD by a fraudulent AD; it leads to EV loss and it alters EV flow. T.RPLY_LD Replay of a load: different IEP are loaded, or the same IEP is loaded several times via a unique load transaction; it leads to EV creation. T.RPLY_PCH_C Replay of a purchase: different PD are credited, or the same PD is credited several times via a unique purchase transaction; it leads to EV creation. T.RPLY_PCH_L Replay of a purchase: different IEP are debited, or the same IEP is debited several times via a unique purchase transaction; it leads to EV loss. T.RPLY_LPC_C Replay of a last purchase cancellation: different IEP are recredited, or the same IEP is recredited several times via a unique last purchase cancellation. It leads to EV creation. T.RPLY_LPC_L Replay of a last purchase cancellation: different PD are debited, or the same PD is debited several times via a unique last purchase cancellation transaction; it leads to EV loss. T.RPLY_CLT Replay of a collect: the same collect transaction is replayed several times to the A; it leads to EV creation. Intersector Electronic Purse and Purchase Device 3 - TOE Security Environment February 1999 Version 1.2 Page 17 of 70 FAILURE 49 A failure occurring during a transaction leads to a non-secure state inducing EV flow non-preservation. This type of threat is divided into 4 threats: FORGERY 50 Forgery of transactions characteristics such as EV amount in order to create or lose EV: T.FAIL_PCH Failure during a purchase transaction: EV is debited from an IEP whereas it is not credited in the PD; it leads to EV loss. T.FAIL_LPC Failure during a last purchase cancellation transaction: EV is debited from the PD whereas it is not recredited to the IEP; it leads to EV loss. T.FAIL_CLT Failure during a collect transaction: EV is collected from a PD whereas it is not credited in the AD; it leads to EV loss. T.FAIL_LD Failure during a load transaction: EV is debited from the LA whereas it is not credited in the IEP; it leads to EV loss. T.FORG_LD_C Forgery of a load transaction in order to credit the IEP with an EV greater than the EV debited in the LD; it leads to EV creation. T.FORG_LD_L Forgery of a load transaction in order to credit the IEP with an EV lesser than the EV debited in the LD; it leads to EV loss. T.FORG_PCH_C Forgery of a purchase transaction in order to credit the PD with an EV greater than the EV debited in the IEP; it leads to EV creation. T.FORG_PCH_L Forgery of a purchase transaction in order to credit the PD with an EV lesser than the EV debited in the IEP; it leads to EV loss. 3 - TOE Security Environment Intersector Electronic Purse and Purchase Device Page 18 of 70 Version 1.2 February 1999 FALSE REPUDIATION Repudiation of transactions or part of transactions by IEP system actors: T.FORG_CLT_C Forgery of a collect transaction in order to credit the AD with an EV greater than the EV collected from the PD; it leads to EV creation. T.FORG_CLT_L Forgery of a collect transaction in order to credit the AD with an EV lesser than the EV collected from the PD; it leads to EV loss. T.REP_LD The PH repudiates (at the EV provider) a load transaction in order to be loaded again; it leads to EV creation. T.REP_PCH The PH repudiates (at the EV provider) a purchase transaction in order to be recredited; it leads to EV creation. T.REP_LPC The PH repudiates (at the EV provider) a last purchase cancellation transaction in order to be recredited; it leads to EV creation. T.REP_CLT The SP repudiates (at its Acquirer) a collect transaction in order to be recredited; it leads to EV creation. T.REP_PCH2 The SP repudiates (at the Purse Holder) a purchase transaction in order to be credited again; it leads to a theft against the PH. T.REP_LPC2 The SP repudiates (at the Purse Holder) a last purchase cancellation transaction in order to be credited again; it leads to a theft. Intersector Electronic Purse and Purchase Device 3 - TOE Security Environment February 1999 Version 1.2 Page 19 of 70 LOSS OF INTEGRITY 51 Data stored at any step of the chain could be modified by unauthorized agents when it is stored or transferred; these concern EV, Flow Traceability data and IEP, PD parameters: 3.4 Organisational Security policies 52 The following organisational security policies are mandatory for the TOE: T.INTEG_EV Unauthorized modification of stored EV. T.INTEG_TD Unauthorized modification of Flow Traceability data. T.INTEG_PARA1 Unauthorized modification of IEP parameters. T.INTEG_PARA2 Unauthorized modification of PD parameters. OSP.DEB_BEF_CRED Debit always precedes credit during transaction. OSP.AGGREG When the PD is able to aggregate several amounts of EV into one overall amount, the result is a new total with the value equivalent to the sum of all the original totals. OSP.PH_BEHAV IEP shall be kept by PH as if they were real purses with coins and bank notes and shall not be lent, specially to untrusted persons. OSP.A_LA_TRUSTED The A and the LA are trusted agent of the EVP. OSP.EV_INDIC There shall exist means to indicate to the PH the amount of the EV of the transaction. OSP.INTENT_TRANS Each IEP transaction is an intentional operation of the user. A procedure defined by the Purse provider shall exist in order to allow the PH either accepts or rejects the transaction. OSP.IEP_ID The IEP shall have a unique identification within the system. OSP.IEP_PD The PD shall have a unique identification for the Acquirer device. 3 - TOE Security Environment Intersector Electronic Purse and Purchase Device Page 20 of 70 Version 1.2 February 1999 OSP.LINK_SP_PD The SP shall be linked to his PD (his bank account has to be credited once the collect is done). OSP.SP_A_CLT The SP can only be collected by his A. OSP.LOAD During a load, the IEP is able to aggregate the amounts of loaded EV to its global overall amount of EV, the result is a new total with the value equivalent to the sum of all the amounts. OSP.ROLE The TOE shall maintain security roles and these roles shall be independent. 24 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 21 of 70 Chapter 4 Security objectives 53 The security objectives for the TOE and for its environment are listed hereafter. 4.1 Security objectives for the TOE 54 The main security objective for the TOE is to ensure EV flow preservation. To do so it shall use state of art technology to achieve the following security objectives: O.EV The TOE security functions shall provide the means to avoid unauthorized creation or loss of EV. O.INTEG_DATA The TOE security functions shall provide the means to avoid unauthorized modification of flow traceability data and IEP or PD parameters during transfers or storage. O.LOGICAL The TOE security functions shall prevent logical entry to the TOE by persons, equipments or processes with no rights to access it and prevent actors from bypassing the EV flow model. O.AUTH The TOE security functions shall ensure authentication of the TOE itself for load devices and acquirer devices. O.ACCESS The TOE security functions shall ensure that user data are only accessed by authorized users. O.OPERATE The TOE security functions shall ensure the continued correct operation of its security functions especially in case of abnormal process of transactions such as interruption during transactions. O.REPLAY The TOE security functions shall ensure that replayed transactions are detected and countered. O.TAMPER The TOE security functions shall prevent physical tampering with its security critical parts. 4 - Security objectives Intersector Electronic Purse and Purchase Device Page 22 of 70 Version 1.2 February 1999 4.2 Security objectives for the environment O.RECORD The TOE security functions shall record flow traceability data to support effective security management. O.LIMIT The stored EV in the IEP shall be limited by the value of a maximum amount. O.DOMAIN The TOE security functions shall maintain a separate domain from other applications for the IEP application. O.SYSTEM The EV Provider shall guarantee the EV in IEP system based on the system security policy. The actors of the system, including the PH shall apply the system security policy. The EV provider shall communicate to the PH the rules dealing with the use of the IEP. O.EV_DISTRIB LD and AD shall not create EV : they shall distribute to authorized parties the same amount of EV they received. O.LA_FAIL LD shall enter a secure state in case of failure during load transactions, abnormal transactions, replayed or forged transactions, without any loss or creation of EV. O.LA_DOMAIN One security domain shall be available for LD for its own execution that protects it from interference and tampering by unstrusted agents. O.LA_RECORD LD shall record necessary events and data to ensure that the information exists to support effective security management. O.AUTH2 LD and AD shall prevent users from gaining access to and performing operations on resources for which they do not have permission. O.PSEUDO During a load, LD shall maintain two separate domains: the debit transaction domain on one hand, and the IEP load transaction on the other hand and these domains shall be separated. O. INSTALL The purse provider shall ensure that the TOE is delivered and installed in a manner which maintains IT security. Intersector Electronic Purse and Purchase Device 4 - Security objectives February 1999 Version 1.2 Page 23 of 70 O. MANAGE The purse provider shall ensure that the TOE is managed, administered and operated in a manner which maintains IT security. O.ACQ AD shall enter a secure state in case of failure during transactions, abnormal transactions, replayed or forged transactions, without any loss or creation of EV. O.A_RECORD AD shall record necessary events and data to ensure that the information exits to support effective security management. 4 - Security objectives Intersector Electronic Purse and Purchase Device Page 24 of 70 Version 1.2 February 1999 36 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 25 of 70 Chapter 5 TOE security functional requirements 55 The TOE security functional requirements define the functional requirements for the TOE using only functional requirements components drawn from the Common Criteria Part 2. 56 The minimum strength of function level for the TOE security requirements is SOF- high. 5.1 Class FAU Security Audit 5.1.1 FAU_GEN.1: Audit data generation 57 The TOE Security Functions shall be able to generate an audit record of the following auditable events: a) Start-up and shutdown of the audit functions, This aspect of the functionality is not applicable: the audit functions are active at any time. b) not specified. c) [assignment: other specifically defined auditable events]. 58 The TSF shall record within each audit record at least the following information: a) Date and time of the event, type of event, subject identity, and the outcome (success or failure) of the event; and Date and time of the event: this has to be interpreted as a sequence of events recognizable by the TOE. b) For each audit event type, based on the auditable event definitions of the functional components included in the PP/ST, [assignment: other audit relevant information]. 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 26 of 70 Version 1.2 February 1999 5.1.2 FAU_SAR.1: Audit review 59 The TSF shall provide [assignment: authorised users] with the capability to read [assignment: list of audit information] from the audit records. 60 The TSF shall provide the audit records in a manner suitable for the user to interpret the information. 5.1.3 FAU_STG.1: Protected audit trail storage 61 The TSF shall protect the stored audit records from unauthorised deletion. 62 The TSF shall be able to detect modifications to the audit records. 5.2 Class FCO Communication 5.2.1 FCO_NRO.2: Enforced proof of origin 63 The TSF shall enforce the generation of evidence of origin for transmitted [assignment: list of information types] at all times. 64 The TSF shall be able to relate the [assignment: list of attributes] of the originator of the information, and the [assignment: list of information fields] of the information to which the evidence applies. 65 The TSF shall provide a capability to verify the evidence of origin of information to [selection: originator, recipient, [assignment: list of third parties]] given [assignment: limitations on the evidence of origin]. Iteration List of defined auditable events as a minimum IEP - last load transaction - last transaction PD - all purchase transactions from last collect - last collect transaction Tab. 5.1 - List of defined auditable events Intersector Electronic Purse 5 - TOE security functional requirements and Purchase Device February 1999 Version 1.2 Page 27 of 70 5.2.2 FCO_NRR.2: Enforced proof of receipt 66 The TSF shall enforce the generation of evidence of receipt for received [assignment: list of information types]. 67 The TSF shall be able to relate the [assignment: list of attributes] of the recipient of the information, and the [assignment: list of information fields] of the information to which the evidence applies. 68 The TSF shall provide a capability to verify the evidence of receipt of information to [selection: originator, recipient, [assignment: list of third parties]] given [assignment: limitations on the evidence of receipt]. Iteration List of information types List of attributes List of information fields Selection Limitations on the evidence of origin Purchase purchase transaction Examples are: - EV, - IEP Id, - unique transaction Id recipient originator EVP immediate Authentication of the IEP IEP identification Authentication of the PD PD identification Tab. 5.2 - Enforced proof of origin iterations Iteration List of information types List of attributes List of information fields Selection Limitations on the evidence of receipt Load load Examples are: - EV, - LA Id, - unique load Id recipient originator EVP at least until the next load transaction Tab. 5.3 - Enforced proof of receipt iterations 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 28 of 70 Version 1.2 February 1999 5.3 Class FCS Cryptographic support 5.3.1 FCS_COP.1: Cryptographic operation 69 The TSF shall perform [assignment: list of cryptographic operations] in accordance with a specified cryptographic algorithm [assignment: cryptographic algorithm] and cryptographic key sizes [assignment: cryptographic key sizes] that meet the following: [assignment: list of standards]. 70 This functionality is needed as a minimum for the following functionalities: - FCO_NRO.2, - FCO_NRR.2, - FIA_UAU.1, - FDP_DAU.1. 5.4 Class FDP: User data protection 5.4.1 FDP_ACC.2: Complete access control 71 The TSF shall enforce the [assignment: access control SFP] on [assignment: list of subjects and objects] and all operations among subjects and objects covered by the SFP. 72 The TSF shall ensure that all operations between any subject in the TSC and any object within the TSC are covered by an access control SFP. 5.4.2 FDP_ACF.1: Security attribute based access control 73 The TSF shall enforce the [assignment: access control SFP] to objects based on [assignment: security attributes, named groups of security attributes]. Collect collect Examples are: - - EV, - - A Id, - - unique collect Id recipient originator EVP immediately after collect reception Last purchase cancellation last purchase cancellation Examples are: - EV, - PD Id, - unique transaction Id recipient originator EVP immediate Iteration List of information types List of attributes List of information fields Selection Limitations on the evidence of receipt Tab. 5.3 - Enforced proof of receipt iterations Intersector Electronic Purse 5 - TOE security functional requirements and Purchase Device February 1999 Version 1.2 Page 29 of 70 74 The TSF shall enforce the following rules to determine if an operation among controlled subjects and controlled objects is allowed: [assignment: rules governing access among controlled subjects and controlled objects using controlled operations on controlled objects]. 75 The TSF shall explicitly authorise access of subjects to objects based on the following additional rules: [assignment: rules, based on security attributes, that explicitly authorise access of subjects to objects]. 76 The TSF shall explicitly deny access of subjects to objects based on the [assignment: rules, based on security attributes, that explicitly deny access of subjects to objects]. 5.4.3 FDP_DAU.1: Basic Data authentication 77 The TSF shall provide a capability to generate evidence that can be used as a guarantee of the validity of EV. 78 The TSF shall provide [assignment: list of subjects] with the ability to verify evidence of the validity of the indicated information. 5.4.4 FDP_ETC.1: Export of user data without security attributes 79 The TSF shall enforce the [assignment: access control SFP(s) and/or information flow control SFP(s)] when exporting user data, controlled under the SFP(s), outside of the TSC. 80 The TSF shall export the user data without the user data’s associated security attributes. Iteration List of subjects IEP Purchase Device Purchase Device IEP Tab. 5.4 - Basic Data authentication iterations 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 30 of 70 Version 1.2 February 1999 5.4.5 FDP_IFC.1: Subset information flow control 81 The TSF shall enforce the [assignment: information flow control SFP] on [assignment: list of subjects, information, and operations that cause controlled information to flow to and from controlled subjects covered by the SFP]. 5.4.6 FDP_IFF.1: Simple security attributes 82 The TSF shall enforce the [assignment: information flow control SFP] based on the following types of subject and information security attributes: [assignment: the minimum number and type of security attributes]. 83 The TSF shall permit an information flow between a controlled subject and controlled information via a controlled operation if the following rules hold: [assignment: for each operation, the security attribute-based relationship that must hold between subject and information security attributes]. 84 The TSF shall enforce the [assignment: additional information flow control SFP rules]. 85 The TSF shall provide the following [assignment: list of additional SFP capabilities]. 86 The TSF shall explicitly authorise an information flow based on the following rules: [assignment: rules, based on security attributes, that explicitly authorise information flows]. 87 The TSF shall explicitly deny an information flow based on the following rules: [assignment: rules, based on security attributes, that explicitly deny information flows]. 5.4.7 FDP_ITC.1: Import of user data without security attributes 88 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. 89 The TSF shall ignore any security attributes associated with the user data when imported from outside the TSC. Minimal Rules handled by the information flow control SFP - mutual authentication for each transaction - secure usage of the maximum amount of EV per IEP Tab. 5.5 - Minimal List of events handled by the information flow control SFP Intersector Electronic Purse 5 - TOE security functional requirements and Purchase Device February 1999 Version 1.2 Page 31 of 70 90 The TSF shall enforce the following rules when importing user data controlled under the SFP from outside the TSC: [assignment: additional importation control rules]. 5.4.8 FDP_SDI.1: Stored data integrity monitoring 91 The TSF shall monitor user data stored within the TSC for [assignment: integrity errors] on all objects, based on the following attributes: [assignment: user data attributes]. 5.5 Class FIA Identification and authentication 5.5.1 FIA_UID.1: Timing of identification 92 The TSF shall allow all TSF-mediated actions except last purchase cancellation on behalf of the user to be performed before the user is identified. The TSF shall require each user to be successfully identified before allowing any other TSF-mediated actions on behalf of that user. 5.5.2 FIA_UAU.1: Timing of authentication 93 The TSF shall allow [assignment: list of TSF mediated actions] on behalf of the user to be performed before the user is authenticated. 94 The TSF shall require each user to be successfully authenticated before allowing any other TSF-mediated actions on behalf of that user. Refinement List of TSF-mediated actions Refinement IEP identification by PD Examples are: - read of EV amount, - read of status, - identification, authentication of PD by IEP. The user is defined as IEP. The IEP is identified on an individual basis. Tab. 5.6 - Identification refinement 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 32 of 70 Version 1.2 February 1999 95 . 5.5.3 FIA_UAU.3: Unforgeable authentication 96 The TSF shall detect and prevent use of authentication data that has been forged by any user of the TSF. 97 The TSF shall detect and prevent use of authentication data that has been copied from any other user of the TSF. 5.5.4 FIA_UAU.4: Single-use authentication mechanisms 98 The TSF shall prevent reuse of authentication data related to [assignment: identified authentication mechanism(s)]. Iteration List of TSF-mediated actions Refinement LA authentication by IEP Examples are: - authentication of the IEP by the LA, - transferring information from the IEP to the LA. The user is defined as the LA. A authentication by PD Examples are: - authentication of PD by A, - transferring information from the PD to A. The user is defined as the A. IEP authentication by PD Examples are: - authentication of PD by IEP, - transferring information from the PD to IEP. The user is defined as the IEP. PD authentication by IEP Examples are: - identification, authentication of IEP by PD, - transferring information from the IEP to PD. The user is defined as the PD. Tab. 5.7 - Authentication iterations Iteration Identified authentication mechanism(s) LA authentication by IEP all authentication mechanisms of the LA A authentication by PD all authentication mechanisms of A IEP authentication by PD all authentication mechanisms of IEP PD authentication by IEP all authentication mechanisms of PD Tab. 5.8 - Single-use authentication mechanisms iterations Intersector Electronic Purse 5 - TOE security functional requirements and Purchase Device February 1999 Version 1.2 Page 33 of 70 5.5.5 FIA_UAU.6: Re-authenticating 99 The TSF shall re-authenticate the user under the conditions [assignment: list of conditions under which re-authentication is required]. 5.6 Class FPT Protection of the TOE Security functions 5.6.1 FPT_FLS.1: Failure with preservation of secure state The TSF shall preserve a secure state when the following types of failures occur: [assignment: list of types of failures in the TSF]. 5.6.2 FPT_PHP.2: Notification of physical attack 100 The TSF shall provide unambiguous detection of physical tampering that might compromise the TSF. 101 The TSF shall provide the capability to determine whether physical tampering with the TSF’s devices or TSF’s elements has occurred. 102 For [assignment: list of TSF devices/elements for which active detection is required], the TSF shall monitor the devices and elements and notify [assignment: Iteration List of conditions LA authentication by IEP - begin of load transaction A authentication by PD - EV collect - flow traceability data delete IEP authentication by PD - begin of purchase transaction - last purchase cancellation transaction. PD authentication by IEP - begin of purchase transaction - last purchase cancellation transaction Tab. 5.9 - Reauthenticating iterations Iteration List of types of failures in the TSF Load load interrupt Purchase purchase interrupt Collect collect interrupt Last purchase cancellation last purchase cancellation interrupt Tab. 5.10 - failure with preservation of secure state iterations 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 34 of 70 Version 1.2 February 1999 a designated user or role] when physical tampering with the TSF’s devices or TSF’s elements has occurred. 5.6.3 FPT_PHP.3: Resistance to physical attack 103 The TSF shall resist [assignment: physical tampering scenarios] to the [assignment: list of TSF devices/elements] by responding automatically such that the TSP is not violated. 5.6.4 FPT_RCV.4: Function recovery 104 The TSF shall ensure that [assignment: list of SFs and failure scenarios] have the property that the SF either completes successfully, or for the indicated failure scenarios, recovers to a consistent and secure state. 5.6.5 FPT_RPL.1: Replay detection 105 The TSF shall detect replay for the following entities: [assignment: list of identified entities]. 106 The TSF shall perform [assignment: list of specific actions] when replay is detected. Iteration List of SFs Failure scenarios Load load interrupt Purchase purchase interrupt Collect collect interrupt Last purchase cancellation last purchase cancellation interrupt Tab. 5.11 - function recovery iterations Iteration List of identified entities List of specific actions Replay detection by IEP of a load by LA LD (load) - if equals to last load then no more action - if different from last load ignore and/or trace Replay detection by PD of a purchase by IEP IEP (purchase) - if equals to last purchase then no more action - if different from last purchase ignore and/or trace Collect PD (collect) collect interrupt Last purchase cancellation PD (last purchase cancellation) last purchase cancellation interrupt Tab. 5.12 - replay detection iterations Intersector Electronic Purse 5 - TOE security functional requirements and Purchase Device February 1999 Version 1.2 Page 35 of 70 5.6.6 FPT_RVM.1: Non-bypassability of the TSP 107 The TSF shall ensure that TSP enforcement functions are invoked and succeed before each function within the TSC is allowed to proceed. 5.6.7 FPT_SEP.1: TSF domain separation 108 The TSF shall maintain a security domain for its own execution that protects it from interference and tampering by untrusted subjects. 109 The TSF shall enforce separation between the security domains of subjects in the TSC. 5 - TOE security functional requirements Intersector Electronic Purse and Purchase Device Page 36 of 70 Version 1.2 February 1999 40 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 37 of 70 Chapter 6 TOE security assurance requirements 110 The assurance requirements is EAL 4 augmented of additional assurance components listed in the following sections. 111 These components are hierarchical ones to the components specified in EAL 4. 6.1 ADV_IMP.2 Implementation of the TSF Developer action elements: 112 The developer shall provide the implementation representation for the entire TOE security functions. Content and presentation of evidence elements: 113 The implementation representation shall unambiguously define the TOE security functions to a level of detail such that the TOE security functions can be generated without further design decisions. 114 The implementation representation shall be internally consistent. 115 The implementation representation shall describe the relationships between all portions of the implementation. Evaluator action elements: 116 The evaluator shall confirm that the information provided meets all requirements for content and presentation of evidence. 117 The evaluator shall determine that the implementation representation is an accurate and complete instantiation of the TOE security functional requirements. 6.2 ALC_DVS.2 Sufficiency of security measures Developer action elements: 118 The developer shall produce development security documentation. Content and presentation of evidence elements: 119 The development security documentation shall describe all the physical, procedural, personnel, and other security measures that are necessary to protect the 6 - TOE security assurance requirements Intersector Electronic Purse and Page 38 of 70 Version 1.2 February 1999 confidentiality and integrity of the TOE design and implementation in its development environment. 120 The development security documentation shall provide evidence that these security measures are followed during the development and maintenance of the TOE. 121 The evidence shall justify that the security measures provide the necessary level of protection to maintain the confidentiality and integrity of the TOE. Evaluator action elements: 122 The evaluator shall confirm that the information provided meets all requirements for content and presentation of evidence. 123 The evaluator shall confirm that the security measures are being applied. 6.3 AVA_VLA.4 Highly resistant Developer action elements: 124 The developer shall perform and document an analysis of the TOE deliverables searching for ways in which a user can violate the TSP. 125 The developer shall document the disposition of identified vulnerabilities. Content and presentation of evidence elements: 126 The documentation shall show, for all identified vulnerabilities, that the vulnerability cannot be exploited in the intended environment for the TOE. 127 The documentation shall justify that the TOE, with the identified vulnerabilities, is resistant to obvious penetration attacks. 128 The evidence shall show that the search for vulnerabilities is systematic. 129 The analysis documentation shall provide a justification that the analysis completely addresses the TOE deliverables. Evaluator action elements: 130 The evaluator shall confirm that the information provided meets all requirements for content and presentation of evidence. 131 The evaluator shall conduct penetration testing, building on the developer vulnerability analysis, to ensure the identified vulnerabilities have been addressed. 132 The evaluator shall perform an independent vulnerability analysis. Intersector Electronic Purse and Purchase Device 6 - TOE security assurance February 1999 Version 1.2 Page 39 of 70 133 The evaluator shall perform independent penetration testing, based on the independent vulnerability analysis, to determine the exploitability of additional identified vulnerabilities in the intended environment. 134 The evaluator shall determine that the TOE is resistant to penetration attacks performed by an attacker possessing a high attack potential. 6 - TOE security assurance requirements Intersector Electronic Purse and Page 40 of 70 Version 1.2 February 1999 68 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 41 of 70 Chapter 7 Rationale 7.1 Introduction 135 This chapter presents the evidence used in the PP evaluation. This evidence supports the claims that the PP is a complete and cohesive set of requirements and that a conformant TOE would provide an effective set of IT security countermeasures within the security environment. 7.2 Security Objectives rationale 136 This section demonstrates that the stated security objectives address all of the security environment aspects identified. 7.2.1 Threats 137 The table 7.1 maps the security objectives for the TOE and the security objective for the environment to the threats identified in the TOE environment.. 7 - Rationale Intersector Electronic Purse and Purchase Device Page 42 of 70 Version 1.2 February 1999 Threats/ Objectives Security objectives for the TOE Security objectives for the environment Para T.LAUND_MON O.LIMIT 138 T.USP_LA_LD O.EV, O.LOGICAL, O.ACCESS 140 T.USP_IEP_LD O.AUTH O.AUTH2 143 T.USP_PP_EVP_PCH O.EV, O.LOGICAL, O.ACCESS 145 T.USP_PP_PCH_IEP O.LOGICAL, O.INTEG_DATA, O.ACCESS 147 T.USP_IEP_LPC O.LOGICAL, O.INTEG_DATA, O.ACCESS 149 T.USP_PP_PCH_PD O.EV,O.LOGICAL,O.INTEG_DATA, O.ACCESS 151 T.USP_PP_EVP_LPC O.EV, O.LOGICAL, O.ACCESS 153 T.USP_PP_EVP_CLT O.AUTH O.AUTH2 155 T.USP_A_CLT O.EV,O.LOGICAL,O.INTEG_DATA, O.ACCESS 157 T.RPLY_LD O.EV, O.REPLAY 159 T.RPLY_PCH_C O.EV, O.REPLAY 161 T.RPLY_PCH_L O.EV, O.REPLAY 159 T.RPLY_LPC_C O.EV, O.REPLAY 165 T.RPLY_LPC_L O.EV, O.REPLAY 167 T.RPLY_CLT O.ACQ 169 T.FAIL_PCH O.EV, O.OPERATE 171 T.FAIL_LPC O.EV, O.OPERATE 173 T.FAIL_CLT O.EV, O.OPERATE O.ACQ 175 T.FAIL_LD O.EV, O.OPERATE O.LA_FAIL 177 T.FORG_LD_C O.EV, O.INTEG_DATA 179 T.FORG_LD_L O.EV, O.INTEG_DATA 181 T.FORG_PCH_C O.EV, O.INTEG_DATA 183 T.FORG_PCH_L O.EV, O.INTEG_DATA 185 T.FORG_CLT_C O.EV, O.INTEG_DATA O.ACQ 187 T.FORG_CLT_L O.EV, O.INTEG_DATA O.ACQ 189 T.REP_LD O.EV, O.RECORD, O.ACCESS O.PSEUDO, O.LA_RECORD, O.SYSTEM 192 T.REP_PCH O.EV, O.RECORD, O.ACCESS O.SYSTEM 194 T.REP_LPC O.EV, O.RECORD, O.ACCESS O.SYSTEM 196 T.REP_CLT O.EV, O.RECORD, O.ACCESS O.A_RECORD, O.SYSTEM 198 T.REP_PCH2 O.ACCESS, O.RECORD O.SYSTEM 200 T.REP_LPC2 O.ACCESS, O.RECORD O.SYSTEM 202 T.INTEG_EV O.EV, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN O.EV_DISTRIB, O.INSTALL, O.MANAGE 204 Tab. 7.1 - Threats and Security objectives Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 43 of 70 Threats on money laundering 138 T.LAUND_MON: money laundering in order to hide the real sources of the money. The IEP could be a means by which laundered money could be stored. 139 The threat T.LAUND_MON is addressed by the security objective for the TOE O.LIMIT: - the objective O.LIMIT avoids the storage of important amount of EV in the IEP. This provides means to prevent laundering. Threats on identity usurpation of IEP system actors 140 T.USP_LA_LD: usurpation of LA identity during a load transaction: a fraudulent load device loads fraudulent EV in an IEP. 141 The IEP is an identified IEP of the system; the fraudulent device is unknown of the system. Fraudulent EV means that this EV has no counterpart of a bank deposit. The IEP may be loaded with fraudulent EV, the result is that the global amount of EV has changed: it leads to EV creation and alters EV flow. The PH may use this amount of fraudulent EV in a purchase transaction. 142 The threat T.USP_LA_LD is addressed by the security objectives for the TOE O.EV, O.LOGICAL and O.ACCESS: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation or loss of EV is not allowed. - the objectives O.LOGICAL and O.ACCESS are applicable to the IEP and ensure that the IEP will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. 143 T.USP_IEP_LD: usurpation of IEP identity during a load transaction: a load device of the IEP system loads a fraudulent IEP with EV. It leads to EV loss if EV is not used in the system anymore or alters EV flow if the fraudulent IEP wants to use this EV in a purchase transaction but this aspect of the threat is detailed by the threat T.USP_PP_PCH_PD. T.INTEG_TD O.ACCESS, O.LOGICAL, O.INTEG_DATA, O.TAMPER, O.DOMAIN 206 T.INTEG_PARA1 O.INTEG_DATA, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN O.INSTALL, O.MANAGE 208 T.INTEG_PARA2 O.INTEG_DATA, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN O.INSTALL, O.MANAGE 210 Threats/ Objectives Security objectives for the TOE Security objectives for the environment Para Tab. 7.1 - Threats and Security objectives 7 - Rationale Intersector Electronic Purse and Purchase Device Page 44 of 70 Version 1.2 February 1999 144 The threat T.USP_IEP_LD is addressed by the security objective for the environment O.AUTH2 and the security objective for the TOE O.AUTH: - the objective O.AUTH2 is applicable to the load device and ensure that the LD will distribute EV only to authorized users (authorized IEP) which have been previously authenticated. - the objective O.AUTH is applicable to the IEP: IEP shall authenticate itself for the load device; this objective is the counterpart of the first one. 145 T.USP_PP_EVP_PCH: usurpation of PP and EVP identity during a purchase transaction: fraudulent EV (unknown from the system, it has no counterpart of a bank deposit) is introduced in the Purchase Device by a fraudulent IEP. The result is that the global amount of EV has changed: it leads to EV creation. 146 The threat T.USP_PP_EVP_PCH is addressed by the security objectives for the TOE O.EV, O.LOGICAL and O.ACCESS: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent creation of EV in the PD is not allowed. - the objectives O.LOGICAL and O.ACCESS are applicable to the PD and ensure that the PD will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. 147 T.USP_PP_PCH_IEP: usurpation of PP identity during a purchase transaction: EV is introduced in the PD by a fraudulent IEP. This threat is comparable to the previous one but in this case, the PD will receive real EV so there is no EV creation, it only alters EV flow. 148 The threat T.USP_PP_PCH_IEP is addressed by the security objectives for the TOE O.LOGICAL, O.ACCESS, and O.INTEG_DATA: - the objectives O.LOGICAL and O.ACCESS are applicable to the PD and ensure that the PD will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. - the objective O.INTEG_DATA is applicable to the PD and ensures that the flow traceability data of the purchase transaction remain unmodified. This would be a means to detect such an attack a posteriori. 149 T.USP_IEP_LPC: usurpation during a last purchase cancellation transaction, of the IEP identity that has achieved the last purchase transaction: a fraudulent IEP tries to debit EV from the Purchase Device during the last purchase cancellation transaction. There is no EV creation but it leads to a theft and alters EV flow. 150 The threat T.USP_IEP_LPC is comparable to the previous threat and is addressed by the same security objectives for the TOE: Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 45 of 70 - the objectives O.LOGICAL and O.ACCESS are applicable to the PD and ensure that the PD will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. - the objective O.INTEG_DATA is applicable to the PD and ensures that the flow traceability data of the last purchase cancellation transaction remain unmodified. This would be a means to detect such an attack a posteriori. 151 T.USP_PP_PCH_PD: usurpation of PP identity during a purchase transaction: EV from a IEP of the system is credited in fraudulent purchase device: there is no EV creation but this threat leads to EV flow inconsistency or EV loss. 152 The threat T.USP_PP_PCH_PD is addressed by the security objectives for the TOE O.EV, O.LOGICAL, O.INTEG_DATA, O.ACCESS: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent loss of EV is not allowed. - the objectives O.LOGICAL and O.ACCESS are applicable to the IEP and ensure that the IEP will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. - the objective O.INTEG_DATA is applicable to the IEP and ensures that the flow traceability data of the purchase cancellation transaction remain unmodified. This would be a means to detect such an attack a posteriori. 153 T.USP_PP_EVP_LPC: usurpation of PP identity and EVP identity during a last purchase cancellation transaction: fraudulent EV (it means that there is no counterpart in a bank deposit) is credited in a IEP of the system by a fraudulent purchase device : it leads to EV creation. 154 The threat T.USP_PP_EVP_LPC is addressed by the security objectives for the TOE O.EV, O.LOGICAL and O.ACCESS: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the IEP is not allowed. - the objectives O.LOGICAL and O.ACCESS are applicable to the IEP and ensure that the IEP will grant access to its own functionalities to authorized users or equipments which have been authenticated as a prerequisite. 155 T.USP_PP_EVP_CLT: usurpation of PP identity and EVP identity during a collect transaction: fraudulent EV (it means that there is no counterpart in a bank deposit) is collected from a fraudulent purchase device by an acquirer device: it leads to EV creation. 156 The threat is addressed by the security objectives for the environment O.AUTH2 and the security objective for the TOE O.AUTH: 7 - Rationale Intersector Electronic Purse and Purchase Device Page 46 of 70 Version 1.2 February 1999 - the security objective O.AUTH2 is applicable to the acquirer device and ensure that the AD will collect EV only to authorized users (authorized PD) which have been previously authenticated. - the security objective O.AUTH is applicable to the TOE (both IEP and PD): IEP shall authenticate itself for the load device and PD shall also authenticate itself for the acquirer device; this objective is the counterpart of the first one. 157 T.USP_A_CLT: usurpation of A identity during a collect transaction: EV is collected from the purchase device by a fraudulent acquirer device. It leads to EV loss and alters EV flow. 158 The threat T.USP_A_CLT is addressed by the security objectives for the TOE O.EV, O.LOGICAL, O.INTEG_DATA, O.ACCESS: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent loss of EV is not allowed. - the objectives O.LOGICAL and O.ACCESS are applicable to the PD and ensure that the PD will grant access to its own functionalities to authorized users or equipments (AD) which have been authenticated as a prerequisite. - the objective O.INTEG_DATA is applicable to the PD and ensures that the flow traceability data of the collect transaction remain unmodified. This would be a means to detect such an attack a posteriori. Threats on replayed transactions 159 T.RPLY_LD: replay of a load: different IEP are loaded or the same IEP is loaded several times via a unique load transaction ; it leads to EV creation. 160 The threat T.RPLY_LD is addressed by the security objectives for the TOE O.EV and O.REPLAY: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the IEP is not allowed. - the objective O.REPLAY is applicable to the IEP and ensure that the IEP will operate in a continuous secure state in case of load replayed transaction; the replayed transaction will be detected and rejected by the IEP. 161 T.RPLY_PCH_C: replay of a purchase: different PD are credited or the same PD is credited several times via a unique purchase transaction; it leads to EV creation. 162 The threat T.RPLY_PCH_C is addressed by the security objectives for the TOE O.EV and O.REPLAY: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent creation of EV in the PD is not allowed. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 47 of 70 - the objective O.REPLAY is applicable to the PD and ensure that the PD will operate in a continuous secure state in case of purchase replayed transaction; the replayed transaction will be detected and rejected by the PD. 163 T.RPLY_PCH_L: replay of a purchase: different IEP are debited or the same IEP is debited several times via a unique purchase transaction ; it leads to EV loss. 164 The threat T.RPLY_PCH_L is addressed by the security objectives for the TOE O.EV and O.REPLAY: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent loss of EV in the IEP is not allowed. - the objective O.REPLAY is applicable to the IEP and ensure that the IEP will operate in a continuous secure state in case of purchase replayed transaction; the replayed transaction will be detected and rejected by the IEP. 165 T.RPLY_LPC_C: replay of a last purchase cancellation: different IEP are recredited or the same IEP is recredited several times via a unique last purchase cancellation transaction ; it leads to EV creation. 166 The threat T.RPLY_LPC_C is addressed by the security objectives for the TOE O.EV and O.REPLAY: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the IEP is not allowed. - the objective O.REPLAY is applicable to the IEP and ensure that the IEP will operate in a continuous secure state in case of purchase replayed transaction; the replayed transaction will be detected and rejected by the IEP. 167 T.RPLY_LPC_L: replay of a a last purchase cancellation: different PD are debited or the same PD is debited several times via a unique last purchase cancellation transaction ; it leads to EV loss. 168 The threat T.RPLY_LPC_L is addressed by the security objectives for the TOE O.EV and O.REPLAY: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent loss of EV in the PD is not allowed. - the objective O.REPLAY is applicable to the PD and ensure that the PD will operate in a continuous secure state in case of last purchase replayed transaction; the replayed transaction will be detected and rejected by the PD. 169 T.RPLY_CLT: replay of a collect: the same collect transaction is replayed several times to the A; it leads to EV creation. This threat is not addressed by the TOE but by its environment. 7 - Rationale Intersector Electronic Purse and Purchase Device Page 48 of 70 Version 1.2 February 1999 170 The threat T.RPLY_CLT is addressed by the security objective for the environment O.ACQ: - the objective O.ACQ ensures that the acquirer device will enter a secure state in case of collect replayed transactions, by detecting any replayed transactions and ignoring them. Threats on failure during transactions 171 T.FAIL_PCH: failure during a purchase transaction: EV is debited from an IEP whereas it is not credited in the PD; it leads to EV loss. 172 The threat T.FAIL_PCH is addressed by the security objectives for the TOE O.EV and O.OPERATE: - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that fraudulent loss of EV in the TOE is not allowed. - the objective O.OPERATE is applicable to the TOE and ensure that the TOE will continue correct operation of its security functions in case of abnormal process during transactions. 173 T.FAIL_LPC: failure during a last purchase cancellation transaction: EV is debited from the PD whereas it is not recredited to the IEP; it leads to EV loss. 174 The threat T.FAIL_LPC is addressed by the security objectives for the TOE O.EV, O.OPERATE: - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that fraudulent loss of EV in the TOE is not allowed. - the objective O.OPERATE is applicable to the TOE and ensure that the TOE will continue correct operation of its security functions in case of abnormal process during transactions. 175 T.FAIL_CLT: failure during a collect transaction: EV is collected from the PD whereas it is not credited to the Acquirer Device; it leads to EV loss. 176 The threat T.FAIL_CLT is addressed by the security objectives for the TOE O.EV, O.OPERATE and the security objective for the environment O.ACQ: - the objective O.EV is applicable to the TOE and ensures EV flow preservation in any case. - the objective O.OPERATE is applicable to the TOE and ensure that the TOE will continue correct operation of its security functions in case of abnormal process during transactions. - the objective O.ACQ ensures that the acquirer device will enter a secure state in case of abnormal process during collect transactions. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 49 of 70 177 T.FAIL_LD: failure during a load transaction: EV is debited from the load device whereas it is not credited in the IEP; it leads to EV loss. 178 The threat T.FAIL_LD is addressed by the security objective for the TOE O.EV, O.OPERATE and the security objective for the environment O.LA_FAIL: - the objective O.EV is applicable to the TOE and ensures EV flow preservation in any case. - the objective O.OPERATE is applicable to the TOE and ensure that the TOE will continue correct operation of its security functions in case of abnormal process during transactions. - the objective O.LA_FAIL ensures that the load device will enter a secure state in case of failure during a load transaction without any loss or creation of EV. Threats on forged transactions 179 T.FORG_LD_C: forgery of a load transaction in order to credit the IEP with an EV greater than the EV debited in the load device; it leads to EV creation. 180 The threat T.FORG_LD_C is addressed by the security objectives for the TOE O.EV, O.INTEG_DATA: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the TOE is not allowed. - the objective O.INTEG_DATA is applicable to the IEP and ensures that the flow traceability data of the load transaction remain unmodified. This would be a means to detect such an attack a posteriori. 181 T.FORG_LD_L: forgery of a load transaction in order to credit the IEP with an EV lesser than the EV debited in the load device; it leads to EV loss. 182 The threat T.FORG_LD_L is addressed by the same security objectives for the TOE O.EV, O.INTEG_DATA: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent loss of EV in the TOE is not allowed. - The objective O.INTEG_DATA is applicable to the IEP and ensures that the flow traceability data of the load transaction remain unmodified. This would be a means to detect such an attack a posteriori. 183 T.FORG_PCH_C: forgery of a purchase transaction in order to credit the PD with an EV greater than the EV debited in the IEP; it leads to EV creation. 184 The threat T.FORG_PCH_C is addressed by the security objectives for the TOE O.EV, O.INTEG_DATA: 7 - Rationale Intersector Electronic Purse and Purchase Device Page 50 of 70 Version 1.2 February 1999 - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that fraudulent creation of EV in the TOE is not allowed. - the objective O.INTEG_DATA is applicable to the TOE and ensures that the flow traceability data of the purchase transaction remain unmodified. This would be a means to detect such an attack a posteriori. 185 T.FORG_PCH_L: forgery of a purchase transaction in order to credit the PD with an EV lesser than the EV debited in the IEP; it leads to EV loss. 186 The threat T.FORG_PCH_L is addressed by the same security objectives for the TOE O.EV, O.INTEG_DATA: - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that fraudulent loss of EV in the TOE is not allowed. - the objective O.INTEG_DATA is applicable to the TOE and ensures that the flow traceability data of the load transaction remain unmodified. This would be a means to detect such an attack a posteriori. 187 T.FORG_CLT_C: forgery of a collect transaction in order to credit the AD with an EV greater than the EV collected from the PD; it leads to EV creation. 188 The threat T.FORG_CLT_C is addressed by the security objectives for the TOE O.EV, O.INTEG_DATA and requires the security objective for the environment O.ACQ: - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that fraudulent creation of EV in the TOE is not allowed. - the objective O.INTEG_DATA is applicable to the PD and ensures that the flow traceability data of the collect transaction remain unmodified. This would be a means to detect such an attack a posteriori. - the objective O.ACQ ensures that the acquirer device will enter a secure state in case of forged collect transactions. 189 T.FORG_CLT_L: forgery of a collect transaction in order to credit the AD with an EV lesser than the EV collected from the PD; it leads to EV loss. 190 The threat T.FORG_CLT_L is addressed by the same security objectives for the TOE O.EV, O.INTEG_DATA and the security objective for the environment O.ACQ: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent creation of EV in the TOE is not allowed. - the objective O.INTEG_DATA is applicable to the PD and ensures that the flow traceability data of the collect transaction remain unmodified. This would be a means to detect such an attack a posteriori. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 51 of 70 - the objective O.ACQ ensures that the acquirer device will enter a secure state in case of forged collect transactions. 191 Threats on forged transactions for last purchase cancellation transactions have not been defined since they could be part of the paragraph threats on loss of integrity: during a last purchase cancellation transaction there is no real EV exchange during the transaction ; this type of threats could be associated to a loss of integrity of the EV stored. Threats on false repudiation 192 T.REP_LD: the PH repudiates a load transaction in order to be loaded again; it leads to EV creation. 193 The threat T.REP_LD is addressed by the security objectives for the TOE O.EV, O.RECORD, O.ACCESS and requires the security objectives for the environment O.LA_RECORD, O.PSEUDO, O.SYSTEM: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the TOE is not allowed. - the objective O.RECORD is applicable to the IEP and ensures that the IEP records necessary events and data (flow traceability data) in order to be presented again as elements of evidence of the real transaction. - the objective O.ACCESS is applicable to the IEP and ensures that flow traceability data will be accessible to authorized users (Purse Provider and EV provider). - the objective O.LA_RECORD is applicable to the load device and ensures that the LD records necessary events and data (flow traceability data) in order to be presented again as an element of evidence of the real transaction. - the objective O.PSEUDO is applicable to the load device and ensures that during a load transaction, there will not be any recorded link between the IEP identity on one hand and the elements of identification of the debit transaction on the other hand. O.LA_RECORD and O.PSEUDO work together. - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been explained to the PH : complaint process, period of time for complaint. 194 T.REP_PCH: a PH repudiates a purchase transaction in order to be recredited at the EV provider. 195 The threat T.REP_PCH is addressed by the security objectives for the TOE O.RECORD, O.EV, O.ACCESS and the security objective for the environment O.SYSTEM: 7 - Rationale Intersector Electronic Purse and Purchase Device Page 52 of 70 Version 1.2 February 1999 - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the IEP is not allowed. - the objective O.RECORD is applicable to the IEP and ensures that the IEP records necessary events and data (flow traceability data) in order to be presented again as an element of evidence of the real purchase transaction. - the objective O.ACCESS is applicable to the IEP and ensures that flow traceability data will be accessible to authorized users (EV provider). - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been explained to the PH : complaint process, period of time for complaint. 196 T.REP_LPC: the PH repudiates a last purchase cancellation transaction in order to be recredited by complaint against the EV provider; it leads to EV creation. 197 The threat T.REP_LPC is addressed by the security objectives for the TOE O.RECORD, O.EV, O.ACCESS and the security objective for the environment O.SYSTEM: - the objective O.EV is applicable to the IEP and ensures EV flow preservation so that fraudulent creation of EV in the IEP is not allowed. - the objective O.RECORD is applicable to the IEP and ensures that the IEP records necessary events and data (flow traceability data) in order to be presented again as elements of evidence of the real last purchase cancellation transaction. - the objective O.ACCESS is applicable to the IEP and ensures that flow traceability data will be accessible to authorized users (EV provider). - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been explained to the PH : complaint process, period of time for complaint. 198 T.REP_CLT: the SP repudiates a collect transaction in order to be recredited; it leads to EV creation. 199 The threat T.REP_CLT is addressed by the security objectives for the TOE O.RECORD, O.EV, O.ACCESS and the security objectives for the environment O.A_RECORD, O.SYSTEM: - the objective O.EV is applicable to the PD and ensures EV flow preservation so that fraudulent creation of EV in the PD is not allowed. - the objective O.RECORD is applicable to the PD and ensures that the IEP records necessary events and data (flow traceability data) in order to be presented again as elements of evidence of the real last purchase cancellation transaction. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 53 of 70 - the objective O.ACCESS is applicable to the PD and ensures that flow traceability data will be accessible to authorized users. - the objective O.A_RECORD is applicable to the acquirer device and ensures that the AD records necessary events and data (flow traceability data) in order to be presented again as an element of evidence of the real transaction. - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been detailed regarding complaint process, period of time for complaint. 200 T.REP_PCH2: the SP repudiates a purchase transaction in order to be credited again; it leads to a theft against the PH. 201 The threat T.REP_PCH2 is addressed by the security objectives for the TOE O.RECORD, O.ACCESS and the security objective for the environment O.SYSTEM: - the objective O.RECORD is applicable to the IEP/PD and ensures that the IEP/PD record necessary events and data (flow traceability data) in order to be presented again as an element of evidence of the real transaction. - the objective O.ACCESS is applicable to the TOE and ensures that flow traceability data will be accessible to authorized users (Purse Provider and EV provider). - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been explained to the PH : complaint process, period of time for complaint. 202 T.REP_LPC2: the SP repudiates a last purchase cancellation transaction in order to be credited again; it leads to a theft. 203 The threat T.REP_LPC2 is addressed by the security objectives for the TOE O.RECORD, O.ACCESS and the security objective for the environment O.SYSTEM: - the objective O.RECORD is applicable to the PD and ensures that the PD records necessary events and data (flow traceability data) in order to be presented again as elements of evidence of the real "last purchase cancellation" transaction. - the objective O.ACCESS is applicable to the PD and ensures that flow traceability data will be accessible to authorized users (Purse Provider and EV provider). - the objective O.SYSTEM is applicable to the TOE environment and ensures that a security policy has been defined and rules have been detailed: complaint process, period of time for complaint. 7 - Rationale Intersector Electronic Purse and Purchase Device Page 54 of 70 Version 1.2 February 1999 Threats on loss of integrity 204 T.INTEG_EV: EV is stored within the TOE in the IEP and in the PD. This threat deals with unauthorized modifications of stored EV. 205 The threat T.INTEG_EV is addressed by the security objectives for the TOE O.EV, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN and the security objectives for the environment O.EV_DISTRIB, O.INSTALL, O.MANAGE: - the objective O.EV is applicable to the TOE and ensures EV flow preservation so that unauthorized modification of EV in the TOE (IEP/PD) is not allowed. - the objective O.LOGICAL is applicable to the TOE and ensures that any user of the TOE will be authenticated accordingly. - the objective O.ACCESS is applicable to the TOE and ensures that any EV modification will be accessible only to authorized users. - the objective O.TAMPER is applicable to the TOE and prevents any physical tampering of the TOE in order to modify any stored EV amounts within the TOE (avoids fraudulent EV creation). - the objective O.DOMAIN is applicable to the TOE and prevents fraudulent usage of the TOE in order to modify any stored EV amounts within the TOE, - the objective O.EV_DISTRIB ensures that EV is not modified during load transactions or collect transactions. - the objective O.INSTALL ensures that fraudulent EV is not created during delivery and installation of the PD or during delivery process of the IEP. - the objective O.MANAGE ensures that the TOE is managed securely: no fraudulent EV is created during any administration procedures. 206 T.INTEG_TD: flow traceability data are stored within the TOE in the IEP and in the PD. This threat deals with unauthorized modifications of flow traceability data. 207 The threat T.INTEG_TD is addressed by the security objectives for the TOE O.INTEG_DATA, O.ACCESS, O.TAMPER, O. DOMAIN and O.LOGICAL: - the objective O.INTEG_DATA is applicable to the TOE and ensures flow traceability data integrity so that unauthorized modification of flow traceability data in the TOE (IEP/PD) is not allowed. - the objective O.LOGICAL is applicable to the TOE and ensures that any user of the TOE will be authenticated accordingly. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 55 of 70 - the objective O.ACCESS is applicable to the TOE and ensures that any modification of flow traceability data will be accessible only to authorized users. - the objective O.TAMPER is applicable to the TOE and prevents any physical tampering of the TOE in order to modify any stored traceability data within the TOE, - the objective O.DOMAIN is applicable to the TOE and prevents fraudulent usage of the TOE in order to modify any stored EV amounts within the TOE. 208 T.INTEG_PARA1: this threat deals with unauthorized modifications of IEP parameters such as maximum amount of EV per transaction, maximum stored EV. 209 The threat T.INTEG_PARA1 is addressed by the security objectives for the TOE O.INTEG_DATA, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN and the security objectives for the environment O.INSTALL, O.MANAGE: - the objective O.INTEG_DATA is applicable to the TOE and ensures that IEP parameters in the IEP will not be modified by fraudulent users. - the objective O.LOGICAL is applicable to the IEP and ensures that any user of the TOE will be authenticated accordingly. - the objective O.ACCESS is applicable to the IEP and ensures that any modification of IEP parameters will be accessible only to authorized users. - the objective O.TAMPER is applicable to the IEP and prevents any physical tampering of the TOE in order to modify any stored parameters within the TOE. - the objective O.DOMAIN is applicable to the TOE and prevents fraudulent usage of the TOE in order to modify any stored EV amounts within the TOE. - the objective O.INSTALL ensures that the delivery process of the IEP is managed securely and appropriate IEP parameters are set. - the objective O.MANAGE ensures that the TOE is managed securely:modification of IEP parameters is under control of security administrative procedures. 210 T.INTEG_PARA2: this threat deals with unauthorized modifications of PD parameters. 211 The threat T.INTEG_PARA2 is addressed by the security objectives for the TOE O.INTEG_DATA, O.LOGICAL, O.ACCESS, O.TAMPER, O.DOMAIN and the security objectives for the environment O.INSTALL, O.MANAGE: 7 - Rationale Intersector Electronic Purse and Purchase Device Page 56 of 70 Version 1.2 February 1999 - the objective O.INTEG_DATA is applicable to the TOE and ensures that PD parameters in the PD will not be modified by fraudulent users. - the objective O.LOGICAL is applicable to the PD and ensures that any user of the TOE will be authenticated accordingly. - the objective O.ACCESS is applicable to the PD and ensures that any modification of PD parameters will be accessible only to authorized users. - the objective O.TAMPER is applicable to the PD and prevents any physical tampering of the TOE in order to modify any stored parameters within the TOE. - the objective O.DOMAIN is applicable to the TOE and prevents fraudulent usage of the TOE in order to modify any stored EV amounts within the TOE. - the objective O.INSTALL ensures that delivery and installation of the PD is managed securely and appropriate PD parameters are set. - the objective O.MANAGE ensures that the TOE is managed securely: modification of PD parameters is under control of security administrative procedures. 7.2.2 Organisational security policies 212 Table 7.2 gives the mapping between organisational security policies to the security objectives. OSP/Objectives Security objectives for the TOE Security objectives for the environment Rationale OSP.DEB_BEF_CRED O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy is in charge of defining every security relevant parameters of the system such as parameters derived from this OSP. OSP.AGGREG O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy is in charge of defining every security relevant parameters of the system such as parameters derived from this OSP. OSP.PH_BEHAV O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; the security rules to be applied by the PH are detailed by O.SYSTEM. Tab. 7.2 - Mapping organisational security policies and security objectives Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 57 of 70 OSP.A_LA_TRUSTED O.EV_DISTRIB O.AUTH2, O.PSEUDO O.ACQ O.LA_FAIL O.LA_RECORD O.A_RECORD O.EV_DISTRIB contributes to this OSP: LD and AD distribute the same amount of EV they have received; there is no creation of EV. O.AUTH2 contributes to this OSP: LD and AD authenticate any user. O.PSEUDO contributes to the same objective: it establishes the domain separation between two domains: debit transaction domain and IEP load transaction domain so that no private information is available on the IEP load transaction domain. O.LA_FAIL and O.ACQ ensure that LD and AD will enter a secure state in case of abnormal events (failure, abnormal transactions, replayed or forged transactions). O.LA_RECORD and O.A_RECORD provide necessary accountability of any security relevant information. OSP.EV_INDIC O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy will have to define such a procedure. OSP.INTENT_TRANS O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy will have to define such a procedure. OSP.IEP_ID O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy will have to define such a procedure. OSP.IEP_PD O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy will have to define such a procedure. OSP.LINK_SP_PD O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; the linkability of the PD to the SP is to be defined by the system security policy. OSP.SP_A_CLT O.LOGICAL O.AUTH O.LOGICAL ensures that the LD will authenticate any AD; O.AUTH ensures that the LD will authenticate itself when communicating with the AD. OSP.LOAD O.SYSTEM O.SYSTEM ensures that a system security policy is in place in the IEP system; this policy is in charge of defining every security relevant parameters of the system such as parameters derived from this OSP. OSP.ROLE O.ACCESS O.SYSTEM O.SYSTEM ensures that all the roles managed by the TOE are defined by the security policy. O.ACCESS ensures that an access control policy defines access rules to the user data; these rules take into account the determined roles of the TOE. OSP/Objectives Security objectives for the TOE Security objectives for the environment Rationale Tab. 7.2 - Mapping organisational security policies and security objectives 7 - Rationale Intersector Electronic Purse and Purchase Device Page 58 of 70 Version 1.2 February 1999 7.2.3 Assumptions 213 Table 7.3 maps assumptions to security objectives. Tab. 7.3 -Mapping assumptions and security objectives 7.3 Security requirements rationale 214 The Security requirements rationale shall demonstrate that the set of TOE security requirements is suitable to meet the security objectives. 7.3.1 Security functional requirements rationale 215 This section demonstrates that the combination of the security requirements is suitable to satisfy the identified TOE security objectives. 216 Each of the TOE security objectives is addressed by either functional or assurance requirements. Assumptions/ Objectives Security objectives for the environment Rationale A.AD O.ACQ Obvious. O.ACQ is a refinement of A.AD A.LA O.LA_FAIL Obvious. O.LA_FAIL is a refinement of A.LA A.INDEP O.LA_DOMAIN Obvious. O.LA_DOMAIN is a refinement of A.INDEP Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 59 of 70 217 The following table demonstrates which requirements contribute to the satisfaction of each TOE security objective. Security objectives/ Requirements O.LIMIT O.EV O.INTEG_DATA O.LOGICAL O.AUTH O.ACCESS O.OPERATE O.REPLAY O.TAMPER O.RECORD O.DOMAIN FAU_GEN.1 X FAU_SAR.1 X FAU_STG.1 X X FCO_NRO.2 X FCO_NRR.2 X FCS_COP.1 X X X X X FDP_ACC.2 X X X FDP_ACF.1 X X X FDP_ETC.1 X X X FDP_ITC.1 X X X FDP_IFC.1 X X FDP_IFF.1 X X FDP_SDI.1 X X X FDP_DAU.1 X FIA_UAU.1 X FIA_UAU.3 X FIA_UAU.4 X FIA_UAU.6 X FIA_UID.1 X FPT_FLS.1 X X X FPT_PHP.2 X X X FPT_PHP.3 X X X FPT_RPL.1 X X X FPT_RCV.4 X X X FPT_RVM.1 X X X X X X X X X X X FPT_SEP.1 X Tab. 7.4 - Mapping of security requirements and TOE security objectives 7 - Rationale Intersector Electronic Purse and Purchase Device Page 60 of 70 Version 1.2 February 1999 218 This section describes why the security requirements are suitable to meet each of the TOE security objectives. Requirements Objectives Rationale FAU_GEN.1 O.RECORD Record of flow traceability data needed for O.RECORD FAU_SAR.1 O.RECORD Review of audited events; contributes to O.RECORD FAU_STG.1 O.RECORD, O.INTEG_DATA Protection of audited events; contributes to O.RECORD and O.INTEG_DATA FCO_NRO.2 O.AUTH Proof of origin of information: applies to purchase transaction, identification elements of IEP and identification elements of PD, then covers O.AUTH FCO_NRR.2 O.RECORD Proof of receipt of information: applies to integrity of any information exchanged with authorized equipments. Necessary for non repudiation of receipt. (O.RECORD). FCS_COP.1 O.EV, O.INTEG_DATA, O.LOGICAL, O.AUTH, O.RECORD The TOE needs a high authentication mechanism based on cryptographic operation (challenge/ response) either to authenticate an equipment (O.LOGICAL) or to authenticate the TOE itself (O.AUTH). The cryptographic operation is also needed for calculation and verification of digital signatures which contribute to O.EV, O.INTEG_DATA or necessary for non repudiation (O.RECORD). FDP_ACC.2 O.EV, O.INTEG_DATA, O.ACCESS Applies directly to O.ACCESS and then O.EV and O.INTEG_DATA FDP_ACF.1 O.EV, O.INTEG_DATA, O.ACCESS Applies directly to O.ACCESS and then O.EV and O.INTEG_DATA FDP_ETC.1 O.EV, O.INTEG_DATA, O.ACCESS The TOE is supposed to exchange user data with authorized equipments. The integrity of these data is to be protected during transmission; these user data will be transmitted without security attributes. FDP_IFC.1 O.LIMIT, O.EV This requirement imposes that information flow is controlled under a precised policy. It applies directly to O.LIMIT (secure usage of maximum amount of EV per IEP) and O.EV (mutual authentication for each transaction). FDP_IFF.1 O.LIMIT, O.EV This requirement precises the information flow control rules with security attributes: it provides definition of those information rules and applies directly to O.LIMIT (secure usage of maximum amount of EV per IEP) and O.EV (mutual authentication for each transaction). FDP_ITC.1 O.EV, O.INTEG_DATA, O.ACCESS The TOE is supposed to receive user data from authorized equipments. The integrity of these data is to be protected during transmission; these user data will be transmitted without security attributes. FDP_SDI.1 O.EV, O.INTEG_DATA, O.ACCESS Applies to integrity of user data during intermediate storage (IEP or PD). Complementary with FDP_ETC.1 and FDP_ITC.1 which concern transmitted user data. FDP_DAU.1 O.EV Applies to integrity of user data during transmission within the TOE (from IEP to PD). Complementary with FDP_ETC.1, FDP_ITC.1, FDP_SDI.1 Tab. 7.5 - Rationale of security requirements Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 61 of 70 FIA_UAU.1 O.LOGICAL Authentication mechanisms; contributes to O.LOGICAL. See table 7.6 below. FIA_UAU.3 O.LOGICAL Authentication mechanisms; contributes to O.LOGICAL. See table 7.6 below. FIA_UAU.4 O.LOGICAL Authentication mechanisms; contributes to O.LOGICAL. See table 7.6 below. FIA_UAU.6 O.LOGICAL Authentication mechanisms; contributes to O.LOGICAL. See table 7.6 below. FIA_UID.1 O.LOGICAL Identification mechanisms; contributes to O.LOGICAL (IEP identification by PD) See table 7.6 below. FPT_FLS.1 O.EV, O.INTEG_DATA, O.OPERATE This requirement imposes that the TOE remains in a secure state in case of any failure; contributes to O.EV, O.INTEG_DATA and O.OPERATE. FPT_PHP.2 O.EV, O.INTEG_DATA, O.TAMPER This requirement implies that the TOE is capable of detecting physical tampering (IEP and PD), (O.TAMPER) covers any fraudulent user data modification by physical tampering within the TOE (O.EV, O.INTEG_DATA). The IEP and PD shall have the same level of security. FPT_PHP.3 O.EV, O.INTEG_DATA, O.TAMPER This requirement implies that the TOE is capable of resisting physical tampering (IEP), PD, (O.TAMPER) covers any fraudulent user data modification by physical tampering within the TOE (O.EV, O.INTEG_DATA). complementary to FPT_PHP.2. The IEP and PD shall have the same level of security. FPT_RPL.1 O.EV, O.INTEG_DATA, O.REPLAY This requirements imposes that the TOE is capable of replay detection which contributes to O.REPLAY. indirectly contributes to integrity of user data (O.EV, O.INTEG_DATA). FPT_RCV.4 O.EV, O.INTEG_DATA, O.OPERATE This requirement provides recovery ensuring either successful completion or recovery to a secure state . FPT_RVM.1 all objectives This requirement applies to all objectives by ensuring that any security function could not be bypassed. FPT_SEP.1 O.DOMAIN This requirement provides domain separation within the TOE ensuring that the IEP application will be independent from other applications. Requirements Objectives Rationale Tab. 7.5 - Rationale of security requirements 7 - Rationale Intersector Electronic Purse and Purchase Device Page 62 of 70 Version 1.2 February 1999 219 The following table describes the case of Identification and Authentication functionnalities. 7.3.2 Security functional requirements dependencies 220 This section demonstrates that all dependencies between security functional requirements components included in this PP are satisfied. 221 The following table lists all functional components, with a numeric number. The dependencies of each component are listed alongside that component with a reference to the line number of the component which satisfies them. Component I&A functionality IEP PD LA Identification There is no identification functionality; identification mechanisms are implicit and associated with Authentication functionality. Not applicable PD Identification IEP Identification Not applicable IEP identification by PD (FIA_UID.1) A identification Not applicable There is no identification functionality; identification mechanisms are implicit and associated with Authentication functionality. LA Authentication LA Authentication by IEP (FIA_UAU.1, FIA_UAU.3, FIA_UAU.4, FIA_UAU.6) Contributes to O.LOGICAL. Not applicable IEP Authentication Not applicable IEP Authentication by PD (FIA_UAU.1, FIA_UAU.3, FIA_UAU.4, FIA_UAU.6) Contributes to O.LOGICAL. PD Authentication PD Authentication by IEP (FIA_UAU.1, FIA_UAU.3, FIA_UAU.4, FIA_UAU.6) Contributes to O.LOGICAL. Not applicable A Authentication Not applicable A authentication by PD (FIA_UAU.1, FIA_UAU.3, FIA_UAU.4, FIA_UAU.6) Contributes to O.LOGICAL. Tab. 7.6 - Identification and Authentication Functionalities Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 63 of 70 reference line numbers followed by (H) indicate that the dependency is satisfied by a hierarchical component to that referenced. 222 Table shows that the functional components dependencies are satisfied by any functional components of the PP except for the components stated in bold characters, which are discussed hereafter. FAU_GEN.1: 223 The dependency with FPT_STM.1 is not relevant to the TOE: correctness of time is no use for the TOE objectives. A refinement of the functionality precises that the Number Name Dependent on Line number 1 FAU_GEN.1 FPT_STM.1 see para 223 2 FAU_SAR.1 FAU_GEN.1 1 3 FAU_STG.1 FAU_GEN.1 1 4 FCO_NRO.2 FIA_UID.1 see para 224 5 FCO_NRR.2 FIA_UID.1 see para 225 6 FCS_COP.1 FDP_ITC.1 or FCS_CKM.1, FCS_CKM.4 FMT_MSA.2 see para 226 7 FDP_ACC.2 FDP_ACF.1 8 8 FDP_ACF.1 FDP_ACC.1, FMT_MSA.3 H(7), see para 229 9 FDP_ETC.1 FDP_ACC.1 or FDP_IFC.1 H(7), 11 10 FDP_ITC.1 FDP_ACC.1 or FDP_IFC.1 FMT_MSA.3 H(7), 11, see para 232 11 FPD_IFC.1 FDP_IFF.1 12 12 FDP_IFF.1 FDP_IFC.1 FMT_MSA.3 11, see para 230 13 FDP_SDI.1 No dependencies - 14 FDP_DAU.1 No dependencies - 15 FIA_UAU.1 FIA_UID.1 see para 231 16 FIA_UAU.3 No dependencies - 17 FIA_UAU.4 No dependencies - 18 FIA_UAU.6 No dependencies - 19 FIA_UID.1 No dependencies - 20 FPT_FLS.1 ADV_SPM.1 EAL4 21 FPT_PHP.2 FMT_MOF.1 see para 233 22 FPT_PHP.3 No dependencies - 23 FPT_RPL.1 No dependencies - 24 FPT_RCV.4 ADV_SPM.1 EAL4 25 FPT_RVM.1 No dependencies - 26 FPT_SEP.1 No dependencies - Tab. 7.7 -Functional dependencies analysis 7 - Rationale Intersector Electronic Purse and Purchase Device Page 64 of 70 Version 1.2 February 1999 "date and time of the event" has to be interpreted as a sequence of events recognizable by the TOE. FCO_NRO.2: 224 The dependency with FIA_UID.1 is not relevant to the TOE: there is no identification functionality for this context; identification mechanisms are implicit and associated with authentication functionality. FCO_NRR.2: 225 The dependency with FIA_UID.1 is not relevant to the TOE: there is no identification functionality for this context; identification mechanisms are implicit and associated with authentication functionality. FCS_COP.1: 226 The dependency with FCS_CKM.1 "Cryptographic key generation" is not relevant; the different keys stored and used by the TOE will be delivered to the TOE. 227 The dependency with FCS_CKM.4 "Cryptographic key destruction" is not relevant: destruction of the keys is out of the scope of the TOE. 228 The dependency with FMT_MSA.2 is not relevant: Security attributes are defined during development and manufacturing of the TOE and could not be modified during operational use. FDP_ACF.1: 229 The dependency with FMT_MSA.3 is not relevant: Security attributes are defined during development and manufacturing of the TOE and could not be modified during operational use. FDP_IFF.1: 230 The dependency with FMT_MSA.3 is not relevant: Security attributes are defined during development and manufacturing of the TOE and could not be modified during operational use. FIA_UAU.1: 231 The table 7.6 describes the dependencies between Identification and Authentication functionalities for the TOE. The dependency between FIA_UAU.1 and FIA_UID.1 is to be understood with this table. In particular, this dependency is only applicable for the case of the IEP Identification and Authentication by the PD. Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 65 of 70 FDP_ITC.1: 232 The dependency with FMT_MSA.3 is not relevant: Security attributes are defined during development and manufacturing of the TOE and could not be modified during operational use. FPT_PHP.2: 233 The dependency with FMT_MOF.1 is not relevant: during operational use of the TOE, the behaviour of security functions could not be changed. 7.3.3 Strength of function level rationale 234 Due to the definition of the TOE, it is very important that the claimed SOF should be high since the product critical security mechanisms have to be only defeated by attackers possessing a high level of expertise, opportunity and resources, successful attack being judged to be beyond normal practicality. 7.3.4 Security assurance requirements rationale 235 The assurance requirements of this Protection Profile are summarized in the following table. Evaluation assurance level rationale 236 An assurance level of EAL4 is required for this type of TOE since it is intended to defend against sophisticated attacks. This evaluation assurance level was selected since it is designed to permit a developer to gain maximum assurance from positive security engineering based on good commercial practices. EAL4 represents the highest practical level of assurance expected for a commercial grade product. In order to provide a meaningful level of assurance that the TOE provides an adequate level of defence against such attacks, the evaluators should have access to the low level design and source code. 237 The assurance level of EAL4 is achievable, since it requires no specialist techniques on the part of the developer. Requirement Name Type EAL4 Methodically Designes, Tested and Reviewed Assurance level ADV_IMP2 Implementation of the TSF Higher hierarchical component ALC_DVS.2 Sufficiency of security measures Higher hierarchical component AVA_VLA.4 Highly resistant Higher hierarchical component Tab. 7.8 - PP assurance requirements 7 - Rationale Intersector Electronic Purse and Purchase Device Page 66 of 70 Version 1.2 February 1999 Assurance augmentations rationale 238 Additional assurance requirements are also required due to the definition of the TOE. 239 ADV_IMP.2 Implementation of the TSF The implementation representation is used to express the notion of the least abstract representation of the TSF, specifically the one that is used to create the TSF itself without further design refinement. IC dedicated software source code and IC hardware drawings are examples of TSF implementation representation. This assurance component is a higher hierarchical component to EAL 4 (only ADV_IMP.1). It is important for a smartcard IC that the evaluator evaluates the implementation representation of the entire TSF and determine if the functional requirements in the Security Target are addressed by the representation of the TSF. ADV_IMP.2 has dependencies with ADV_LLD.1 “Descriptive Low-Level design”, ADV_RCR.1 “Informal correspondence demonstration”, ALC_TAT.1 “Well defined development tools”. These assurance components are included in EAL4, then these dependencies are satisfied. 240 ALC_DVS.2 Sufficiency of security measures Development security is concerned with physical, procedural, personnel and other technical measures that may be used in the development environment to protect the TOE. This assurance component is a higher hierarchical component to EAL4 (only ALC_DVS.1). Due to the nature of the TOE, there is a need for any justification of the sufficiency of these procedures to protect the confidentiality and integrity of the TOE. ALC_DVS.2 has no dependencies. 241 AVA_VLA.4 Highly resistant Due to the definition of the TOE, it must be shown to be highly resistant to penetration attacks. This assurance requirement is achieved by the AVA_VLA.4 component. Independent vulnerability analysis is based on highly detailed technical information. The attacker is assumed to be thoroughly familiar with the specific implementation of the TOE. The attacker is presumed to have a high level of technical sophistication. AVA_VLA.4 has dependencies with ADV_FSP.1 “Informal functional specification”, ADV_HLD.2 “Security enforcing high-level design”, ADV_LLD.1 “Descriptive low-level design”, ADV_IMP.1 “Subset of the implementation of the Intersector Electronic Purse and Purchase Device 7 - Rationale February 1999 Version 1.2 Page 67 of 70 TSF”, AGD_ADM.1 “Administrator Guidance”, AGD_USR.1 “User Guidance”. All these dependencies are satisfied by EAL4. 7.3.5 Security requirements are mutually supportive and internally consistent 242 The purpose of this part of the PP Rationale is to show that the security requirements are mutually supportive and internally consistent. 243 EAL4 is an established set of mutually supportive and internally consistent assurance requirements. 244 The dependencies analysis for the additional assurance components in the previous section has shown that the assurance requirements are mutually supportive and internally consistent (all the dependencies have been satisfied). 245 The dependencies analysis for the functional requirements described above demonstrates mutual support and internal consistency between the functional requirements. 246 Inconsistency between functional and assurance requirements can only arise if there are functional-assurance dependencies that are not met, a possibility which has been shown not to arise. 7 - Rationale Intersector Electronic Purse and Purchase Device Page 68 of 70 Version 1.2 February 1999 70 Intersector Electronic Purse and Purchase Device February 1999 Version 1.2 Page 69 of 70 Annex A Glossary Acquirer (A) An acquirer is a trusted agent of the EV provider who is responsible for collecting EV and, if possibly, flow traceability data, from purchase devices concerning purchase and purchase cancellation transactions. Acquirer Device (AD) In order to handle the collection transactions the acquirer operates one or more acquirer devices. Electronic Value (EV) Electronic Value (EV) is the counterpart of funds received by the EV provider. It is defined by the identity of the EV provider, the currency denomination and the amount. EV Provider (EVP) The EV provider guarantees the EV in IEP system. To this end, the EV provider: - creates and dispenses EV in exchange for funds received, - redeems collected EV and destroys it. Intersector Electronic Purse (IEP) The IEP consists of an Integrated Circuit (IC) with an embedded software. The IC could support other applications including other IEPs. The main characteristics of an IEP are that it is prepaid, reloadable, anonymous and interacts with the other part of the TOE: the purchase device. Purse Provider A purse provider is fully responsible for the security of the IEP system. For example, he is responsible for the security of the IC itself and of the embedded software that can affect EV processing.The purse provider is also responsible for administration of IEP and PD such as applets load or parameters update. In order to handle the administration operations the purse provider operates one or more administration devices. Administration operations include security management. A - Glossary Intersector Electronic Purse and Purchase Device Page 70 of 70 Version 1.2 February 1999 Service Provider (SP) A service provider sells services for which he accepts payment by IEP. In order to handle the purchase transactions the service provider operates one or more purchase devices in which he stores EV until collection and other information for his own purposes, if needed.