Research And Design On Trust Model Of SPKI Collaborative Groups

For providing distributing access control and settling complicated global denomination and centralization deployment, scholars Carl Ellison and Ronald Rivest from MIT proposed SPKI which receives extensive attention. SPKI acquires extensive application like web services, peer-to-peer networks, grid application and wireless local area network etc. For a large-scale distributing network, however, there exist some flaws in SPKI, there are: certificate searching, trust building and system using etc. Aiming at these flaws in a large-scale distributing network, we propose an SPKI-based collaborative groups trust model which provides trust building mechanism, method of certificate management and function for certificate searching. Aiming at the problem of certificate management and system usage, we design and implement the certificate management system in model by importing XKMS, aiming at the certificate searching for collaborative groups, we design certificate searching algorithm between groups. The major contributions in the dissertation include:①Following the analysis the existing flaws of SPKI in large-scale distributing network, combining with the thought of collaborative group and theory of SPKI certificate, a collaborative group trust model based on SPKI is proposed. According to the proposed model, we build trust relationship between distributing entities, and provide feasible method for certificate management and mechanism for certificate searching.②We design the framework of certificate management system in collaborative group trust model, construct the system structure in certificate management and partition different function modules. Conforming to the XML key management specification, we design and implement XKMS service module in certificate management system so as to provide simple, convenient usage, what's more, it has no effect on existing SPKI.③Following the analysis of the certificate searching in collaborative group, we research the feasibility of solving the certificate searching by referring the P2P search algorithm, and analyze comparatively available P2P search algorithms in context of certificate searching. Basing on the analyses, a correlativity-based dynamic selecting enquiring algorithm is proposed, which improves the performance. The emulation results show the proposed algorithm is effective.