The security architecture of the PSCS system is independent of special cryptographic algorithms. It also provides a mechanism for the distributed management of public keys and related data. The main part of the security related software in the PSCS demonstrator deals with the integration of the required smart card system, the provisioning of cryptographical functionality, the protocol implementation using SDL, and the system-independent representation of data structures for use within cryptographic protocols. The use of a smart card is twofold. It also allows secure storage of keys and certificates which are necessary to perform authentications, and is used to store private user data as for example the private address book.
Cryptographic protocols require unambiguous data representation.
Thus, all messages and cryptologic data has been specified using ASN.1. Most of them are compliant to existing standards like X.509 and PKCS . From this specification, executable code for the demonstration system has been generated. Starting from a first implementation, several modifications of the authentication scheme has been applied, resulting in a significant speed up of authentication. Several utilities allowing personalisation of smart cards and also generation of certificates as well as public keys have been implemented.