A User Centric Security Model for Tamper-Resistant Devices

4.3 Trusted Environment & Execution Manager
one smart card to another, the backup & restoration manager retrieves these tokens from
the backup token handler, encrypts them, and communicates to the intended entity (e.g.
backup server or new smart card). The details of this mechanism are further elaborated
in chapter 9.
4.3.3 Runtime Security Manager
The runtime security manager deals with the enforcement of the platform policies regarding
the smart card runtime environment. These policies may deal with the security and
reliability of an application execution, and they ensure that an application executes in a
trustworthy manner. The runtime security manager is discussed in detail in chapter 8
where we examine the threats to the smart card runtime environment and related countermeasures.
4.3.4 Attestation Handler
The attestation handler and the self-test manager are part of the security assurance and
validation mechanism discussed in section 4.4. The dierence between these two modules
(i.e. the attestation handler and the self-test manager) of the TEM is that one focuses
on the software and the other on the hardware. However, in the proposed attestation
mechanism (section 4.5) they complement each other to provide proof that a smart card
is secure, reliable and trustworthy.
During the application installation process, the attestation handler will verify the current
state of the platform runtime environment (e.g. security and operationally sensitive parts of
the SCOS) and arm to the appropriate SP that the platform is as secure and reliable as it
is claimed to be the evaluation certicate discussed in section 4.4. Once the application is
installed the relevant SP can ask the TEM to generate the state validation of an application
(e.g. signed hash of the application), ensuring that the application is downloaded without
any errors onto the platform. This function of the TEM is similar to the DAP [30, 74].
Furthermore, SPs can request the state validation of their applications at any time during
the lifetime of the applications on a smart card. In addition, as part of the application
sharing mechanism the TEM also provides application state validation to the applications
that share each other's resources (discussed in chapter 7).
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