A Time and Mutable Attribute-Based Access Control Model

Access control is one of the most important technologies to guarantee computer security. A new model with support for valid time and usage constraint is described based on full analysis of flaws in existing models. In the new model, authorization rules can express access control policies completely and access constraints are necessary conditions to prevent authorization abuse. To solve the problems in implementation of the model, a sound scheme for administration of authorizations is proposed and some access decision algorithms are developed.