Secure network coding against intra/inter-generation pollution attacks

By allowing routers to combine the received packets before forwarding them, network coding-based applications are susceptible to possible malicious pollution attacks. Existing solutions for counteracting this issue either incur inter-generation pollution attacks (among multiple generations) or suffer high computation/bandwidth overhead. Using a dynamic public key technique, we propose a novel homomorphic signature scheme for network coding for each generation authentication without updating the initial secret key used. As per this idea, the secret key is scrambled for each generation by using the generation identifier, and each packet can be fast signed using the scrambled secret key for the generation to which the packet belongs. The scheme not only can resist intra-generation pollution attacks effectively but also can efficiently prevent inter-generation pollution attacks. Further, the communication overhead of the scheme is small and independent of the size of the transmitting files.