Two improved homomorphic MAC schemes in network coding

Network coding provides the advantage of maximizing the usage of network resources, but the natural properties of network coding also make the pollution attack more threatening. Much work on resisting pollution attacks is through homomorphic MACs. But majority have same security parameter 1/q. In this paper, we present two ways to construct homomorphic MAC which improve the performance of previous schemes. The security parameters of our MACs are 1/q^l1 and 1/q^l2, respectively. Besides the higher security, our MAC schemes have lower computational complexity.