Trust Propagation Model for Federated Virtual Commnunities

Trust management is a new security technology for computer networks. A virtual community (VC) is a trust domain. In trust management, trust propagation is crucial within a VC. Moreover, trust propagation for federated VCs (FVCs) is also important with various federated mechanisms arising. In order to implement trust propagation for FVCs, a layered trust management architecture is proposed and trust evaluation on VCs is also considered. Then trust propagation for a new entity for FVCs is discussed as an example. During trust propagation for FVCs, privacy protection is a focus. Two typical privacy-protected trust propagation models for FVCs are proposed and their workflows are designed in detail. They are simple trust propagation model (STPM) and identity ticket-based trust propagation model (ITTPM). Besides the sameness, ITTPM is more complex than STPM. However, ITTPM is more flexible than STPM while STPM can protect more user privacy than ITTPM. Our method meets requirements of trust management of VCs and takes into account security and factors that will influence the definition of trust inside an identity system.