Secure network coding based on homomorpuic signature against pollution attacks

The network coding systems are vulnerable to pollution attacks, in which the adversary forwarders can inject polluted or forged messages into networks. In this paper, we propose a homomorphic signature scheme to provide security protection against pollution attacks, which mainly uses the homomorphic property of signature based on Paillier cryptosystem. On one hand, it guarantees the forwarders to verify the received messages effectively. If the verification is failed, the message is assumed to be polluted and should be discarded. On the other hand, the proposed scheme can generate the valid signatures for its output messages from the signatures of input ones without knowing the source's private key such that extra secure channels are not needed. We also make the security analysis and prove that our signature scheme is secure enough to defend against pollution attacks.