On Security Problems Of Network Coding

We know traditional "store and forward" mechanism can not achieve maximum channel capacity. Network coding, on the other hand, encourages intermediate nodes in the network combine information streams. This mechanism can improve throughput, reduce congestion and make network decentralized and more reliable.However, since network coding encourages intermediate nodes combine data streams, it is highly susceptible to "pollution attacks". We know that there may be some attack-ers in communication network. Pollution attacks means these attackers forge or modify some information and insert it into the network. A small part of corrupted information can cause a large-scale pollution propagation, which will make the sink node unable to decode the data it need. Intermediate nodes in the network will waste a large amoun-t of computational resources and bandwidth. Also, pollution attacks will reduce the throughput of the network.When we want to apply network coding to practical use, there are a lot of problems processing for solutions. The most important one is the defence against pollution attacks. If we can’t guarantee the integrity of information during the network coding process, the advantages of network coding are meaningless. This paper is mainly on defence against pollution attacks based on cryptographic approach. Our main results are given as follows:(1) We proposed a symmetric-key based scheme for single-source network coding. Some schemes that use Message Authentication Code (MAC) have been proposed for resisting this attack. However, these schemes could be broken with probability 1/q, where q is the size of the underlying field. Although the trace function has already been used for constructing MAC for a higher security, it can only be used for single-generation distribution. This paper proposes a novel MAC-based scheme that also employs trace function. However, different from prior work, our scheme can be immediately used for secure multi-generation distribution.(2) To address the problem in multi-source network coding, some schemes are pro-posed. However, these previous schemes for inter-session have some disadvantages:some of them are computationally inefficient and the computationally efficient one has a high bandwidth overhead. In this paper, we propose a novel hybrid cryptographic scheme for multi-source network coding. Our scheme is resistant to pollution attacks. In particular, with the use of hybrid cryptographic, our scheme have a low computation overhead and the polluted packets can be dropped at the intermediate nodes, which can significantly save the bandwidth consumption compared to previous schemes. CLC:TP393...