Research Of Network Coding For Peer-to-Peer Network

The traffic from peer-to-peer networks accounts for more than 50 percent of the total traffic on the Internet, and is still increasing. Therefore, improving the bandwidth utilization of p2p networks becomes more and more urgent. Network coding was first proposed by Ahlswede, etc in 2000. It allows intermediate node in the network to process the information received, in this way, it can improve bandwidth utilization and ensure information security, etc. So the purpose of this article is to study secure network coding scheme suitable for p2p networks.In this paper, we first introduce the basic definition of network coding and focus on studying the existing applications based on network coding. Then, we analyze the basic principles, advantages and disadvantages of network coding in p2p network. At last, we propose a novel secure network coding scheme for p2p network. Our scheme consists of three functional modules that cross-generational random linear network coding module (CGRLNC), anti-wiretapping network coding module (AWNC) and anti-pollution network coding module (APNC), the three ones cooperate together.The first module (CGRLNC) is designed to overcome the weakness of the existing three kinds of network coding approaches in the p2p network, it implements random linear network coding in the set of generations using sparse matrix as the local coefficient matrix. The set of generations is constituted by the generation and the one before it. We provide its theoretical analysis and simulation analysis. The results show that our scheme can achieve win-win effect of the three existing in p2p networks and using sparse matrix as the local coefficient matrix can reduce its computational complexity of encoding packets.The second module (AWNC) aims at solving the wiretapping problem in the p2p network, we use the vandermonde matrix having the characteristics of lower triangular matrix to process information at the sources and sinks. We analyze the security of our scheme and discuss its performance. Our scheme can achieve weak security. In addition, it also can reduce the time and space complexity with the limit of up to 50% compared to similar scheme.The last module (APNC) is designed to detect and filter the packet polluted as soon as possible, we construct a signature scheme based on linear homomorphic function and RSA to sign the information at the sources and intermediate nodes before sending and verify it at the sinks and intermediate nodes after receiving. We prove the security of our scheme and analyze its efficiency. Our scheme can be used to avoid pollution, the time complexity of its verification is much less than those in the similar signature schemes.