Trust Management In Distributed System

Trust management is a better and more efficiency authorization mechanism which deals with the credentials, security policies and trust relationships integrated, and do authorization directly. It is better suited for Internet which is a kind of decentralized network with large scale and complex structure.My thesis aims to do some research about trust management comprehensively, analyze its framework and principles of operations. For the important issue of trust management—the certificate chain discovery, some thorough research will be done to try to find a better searching algorithm.Synthetic analysis about the structure, basic knowledge and characteristics of trust -management has been done in this thesis. Comparison between different trust management systems can be found in this thesis and their merits or shortcomings are shown.In this thesis, some certificate graphs are used to denote the certificates and certificate chains. For SDSI name certificates, a real distributed searching algorithm is introduced, we can do a conclusion that with this kind of algorithm, we can search and discovery the related certificates and assemble a certificate chain when all name certificates are stored in an appropriate manner. It is shown that the algorithm has good soundness and completeness, it is more flexible and efficient and has better performance in Internet where millions of certificates are distributed stored.