Design and implement of file sharing system with identity certification based on CL-PKC in P2P networks

File sharing is one of the most typical applications in P2P networks. Due to the problems of certificate management and key escrow, the traditional public key cryptosystems including PKI and ID-PKC are very difficult to be applied in the P2P networks. Identity authentication is always hard to be brought into effect, which brings some trust problems, such as free riding. The trust problems widely exist in such file sharing systems. In this paper, we research the applications with identity certification based on certificateless public key cryptography (CL-PKC), and build a file sharing system based on the JXTA platform in the P2P networks. The system implements key generation, identity authentication and file content authentication, verifies its feasibility and validity, and proves that it is so secure.