An Information Flow Security Model to Trusted Computing System

In this paper, we introduce a new information flow model for trusted computing systems.Different from traditional system protection models, such as access control matrix model, this model analyze the information flow in the sys- tem by tracing the operation sequences , and explains that the security status of a trusted computing system is the secu- rity attributes of information flows from input port to output port.With this model, we discuss the information channels in a trusted computing systems, and propose a "normal in- formation flow theorem" which gives a necessary condition of the existence of normal information flow.