Split Null Keys: A Null Space Based Defense for Pollution Attacks in Wireless Network Coding
Recent work in defending against pollution attacks for intra-flow network coding systems proposed a null spaces based algebraic approach which has a smaller computation cost than previous pollution defenses. The approach requires the source to distribute keys periodically, but in order to scale involves forwarder nodes in the creation of new keys and their distribution. As a result the key distribution is secure only in specific network topologies such as those created by large-scale peer to peer systems, and is not secure in wireless networks where such topologies do not exist. The authors propose Split Null Keys, which splits the keys such that only a small portion of the key is updated periodically.