Extending the schematic protection model - II. Revocation

The Schematic Protection Model (SPM) allows us to specify the protection structure of a system and gives an algorithm to reason about the transmission of privileges in the system. This paper extends the SPM model to address revocation of privileges. In Varadharajan and Calvelli, Extending the Schematic Protection Model - I: authentication and conditional tickets, Proceedings of the 1994 IEEE Symposium on Research in Security and Privacy [1], we had proposed an extension of the SPM to provide authentication. The two extensions are independent in the sense that each one affects a different part of the decision algorithm.