Trust Representation and Reasoning for Access Control in Large Scale Distributed Systems

The Internet-based large scale distributed applications have huge and changeable user groups, which brings forward a new problem for access control in the systems. The traditional access control methods are identification based and closed, which can not satisfy the new security requirement of the large scale distributed systems. Trust-based access control is dynamically scalable which has provided a new way for solving this problem. Trust representation and reasoning is the fundamental issue in trust-based access control. In this paper, we first analyze the properties of trust in human society, and describe the attributes of trust in the context of access control. Then basing on the fuzzy set theory, we suggest a mathematic model for trust representation and reasoning. An example is given for showing how the model can be used to represent trust.