A User Centric Security Model for Tamper-Resistant Devices

4.4 Security Assurance and Validation Mechanism
evaluation-standard of choice. CC evaluation has a well-established security requirement
specication [69] and evaluation methodology [130]. Furthermore, card issuers, application
providers, and most smart card manufacturers have extensive experience of the CC
evaluation scheme.
In subsequent sections, we discuss how CC plays the role of trusted third party (evaluator)
in the UCOM security assurance and validation process.
4.4.2 Assurance Phase
This section describes the pre-issuance security evaluation. It is divided into two subsections:
smart card evaluation and application evaluation.
4.4.2.1 Smart Card Evaluation
In this phase, the card manufacturer would get their smart cards evaluated to the dened
EAL. If the evaluation of the smart card is successful, the CC Certication Body (CB)
would issue a cryptographic certicate [132], referred to as the Platform Assurance Certicate
(PAC). The main components of the certicate include a PAC identier, a unique
reference to the product's ST, PP, and list of hardware security mechanisms and a hash of
the immutable (security and reliability critical) part of the SCOS.
Smart cards could be subjected to extensive evaluation by the manufacturer, evaluation
labs, or the academic community even after the issuance of the card's PAC; therefore, if
such evaluations discover vulnerabilities in a particular product, SPs can disable their application
leases to them, preventing the smart cards from accessing the sanctioned services.
Furthermore, the CB may downgrade their PAC assurance level or include the card on a
certication revocation list, prohibiting such smart cards from downloading applications
in the future.
In addition, a PAC can also have the manufacturer's ID, the evaluator's (Commercial
Licensed Evaluation Facility: CLEF) ID, the manufacturer's signature verication key
[132], and the validity period. The validity period is determined by the CC evaluators
and it represents an estimated period that a given product is expected to remain secure.
The manufacturer's ID uniquely identies the smart card manufacturer, and similarly the
CLEF ID identies the evaluation body that has carried out the evaluation. Finally, the
certicate would also certify the manufacturer's signature key pair.
The manufacturer would use the signature key certied by the PAC to issue certicates to
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