P2P information flow model based on trust and security grade

Introducing the reputation grade, classifications and access control grade, a new information flow model on P2P based on trust and security grade was described, with the security classification achieved by access control grade, and with the information flow role described by access control grade of two objects. This information flow model satisfies the characteristics of finite lattice and least upper bound operator in existing literature. It is reasonable and safe, and it is an expansion of information flow model based on BLP model.