A Trust and Context Based Access Control Model for Distributed Systems

In order to overcome the limitations in traditional access control models such as identity-based access control and meet the access requirements in distributed systems, we propose a Trust and Context based Access Control model called TCAC, it extends the traditional RBAC (role based access control) model with the notion of trust and context. Role assignment in TCAC is based on the trustworthiness and context information of users. The TCAC model is flexible, scalable, and well suitable for the dynamic and distributed systems. Then we provide a trust evaluation mechanism based on the local and global reputation to compute the trust value of a user in distributed system, which can avoid malicious nodes behave correctly in order to get the highest possible trust value. Finally an implementation framework of the access control system based on TCAC is described.