The reliable authentication of user attributes is an important prerequisite for the security of web based applications. Digital certificates are widely used for that purpose. However, practical certification scenarios can be very complex. Each certificate carries a validity period and can be revoked during this period. Furthermore, the verifying user has to trust the issuers of certificates and revocations. This work presents a formal model which covers these aspects and provides a theoretical foundation for the decision about attribute authenticity even in complex scenarios. The model is based on the event calculus, an AI technique from the field of temporal reasoning. It uses Clark's completion to address the frame problem. An example illustrates the application of the model.
Subjects: 1. Applications; 3.6 Temporal Reasoning
Submitted: Apr 16, 2007