Anonymous authorization in trust management

An anonymous authorization mechanism was proposed to protect the user's privacy in the process of authorization in trust management. User requested for services using their real identification in most of the classic trust-management language system, which potentially leaded to the privacy leaking. Through dynamically searching for the delegation roles which take over the request, the anonymous authorization mechanism retained the right behavior of credential chain discovery and achieved a quantitative way of anonymity against the resource provider. Results showed that the anonymous mechanism shared the same worst-case time complexity with the traditional forward credential-chain-searching method. A method of caching all the members in the nodes was proposed to improve the performance in time spending. Simulation results showed that the performance in time spending greatly improved in the relative stable systems, in which the credentials change slowly.