The Research On Anonymity Authentication And Traceability Of P2P Network

With the development of personal computers, Peer-to-Peer networks are widely used in various fields and shows great potential. As well as P2P network bringing facilities for people to communicate and share knowledge. The safety of P2Ps is the point of concern in the current research. Anonymity has received increasing attention in the literature due to the users’ awareness of their privacy protection. While anonymity related issues have been extensively studied in peer-to-peer (P2P) systems, numerous concerns have been raised about the issue of providing authentic partners in P2P systems. In addition, the network authority requires authentication so that malicious user who abuse anonymity in the network remain traceable. These three considerations lead to the conclusion that P2P systems must have some methods that can satisfy not only anonymity but also authentication and traceability. However, for one peer to authenticate and trace others, he needs to know the identity of the other peers, which affects anonymity. Thus, there exists an inherent contradiction between anonymity and trust or traceability in P2P systems. This dissertation analyzes this problem and reviews related researches. In addition, we propose four schemes for this problem.Firstly, in FBST, we propose a security architecture to ensure anonymity and authentication for honest users and keep traceability for misbehaving users in P2P systems. We use Fair Blind Signature Trust (FBST) to resolve the conflict among anonymity, authentication and traceability. Signature that has information about identity ensures authentication. At the same time, blindness of signature and additional anonymous scheme provides anonymity. Moreover, traceability is achieved due to the fairness of fair blind signature. However, FBST only support PKI based scheme, and this assumption in distributed P2P environment is actually very difficult to achieve.Secondly, in CST, we use Collaboration Signature Trust (CST) to resolve the conflicts among anonymity, authentication and traceability without PKI assumption. The tradeoff between anonymity and authentication is achieved due to the novel collaboration signature. Security analysis shows that the CST can perfectly resolve tradeoff between anonymity, authentication and traceability.Then, in FHET, for cluster based P2P system, we use fully homomorphic encryption to design Fully Homomorphic Trust (FHT). This mechanism is more lightweight and less complex than the previous two and can prevent self-behavior of peer.Eventually, compared with FBST, CST, FHST of system control, from the path control perspective, we propose a multiple marking trace mechanism based on watermarking and Possibility Packet Marking(PPM), which is called SWP2P. One possible approach is to use the idea of code division multiple access (CDMA) technology to mark more information in sole packet by superposition mode.In summary, we analyzed the tradeoff between anonymity and authentication in P2P network environment. Besides, aiming at different application scenario, we proposed four reasonable and effective schemes. Our research has theoretical and practical value for advancing the theory and practicability of reliable transaction in P2P networks.