H-Trust: A Robust and Lightweight Group Reputation System for Peer-to-Peer Desktop Grid

We propose a robust and lightweight group reputation system, called H-Trust, inspired by the h-index aggregation technique. Leveraging the robustness of the h-index algorithm under incomplete and uncertain circumstances, H-Trust offers a robust reputation evaluation mechanism for both individual and group trusts with minimal communication and computation overheads. The five phases of H-Trust scheme are presented in detail, including trust recording, local trust evaluation, trust query phase, spatial-temporal update phase, and group reputation evaluation phases. The rationale for its design, the analysis of the algorithm complexity and security level are further elaborated. To validate the performance of H-Trust scheme, we conduct multi-agent based simulations. Simulation results demonstrate that H-Trust is robust and can aggregate cooperative groups in systems even when the majority of users are malicious.