Efficient trust based information sharing schemes over distributed collaborative networks

In distributed collaborative networks such as peer-to-peer systems, privacy preserving information sharing and dissemination heavily relies on effective trust management. Trust based encryption (TBE) has been proposed to be a solution to enabling privacy preserving information sharing and dissemination for such networks. Unfortunately, the previously proposed schemes are not efficient in terms of communications overhead, and require a constantly online trust authority. In this paper, we propose two trust based encryption schemes with significantly improved efficiency. In the first scheme, we develop a generic transformation approach based on the recently proposed identity based broadcast encryption (IBBE) technique, which can significantly reduce both memory space and communication overhead when static reputation is considered. For the dynamic reputation scenarios, we present a trust based encryption scheme which is based on a recently proposed revocable identity based encryption technique, resulting in significantly reduced communication overhead at the central trust authority.