An Efficient Short Null Keys Based Scheme for Securing Network Coding Against Pollution Attacks

Network coding has gained wide attention nowadays for its significant advantages on many aspects compared with traditional routing mechanism. However, if there are malicious nodes launching pollution attacks by tampering or forging data packets in the communication network, the sink nodes will suffer from failure decoding, together with serious results such as bandwidth wasting, longer transmission delay and increasing computation overheads. The original null keys based pollution detection scheme cannot efficiently defend against pollution attacks when the system has colluding attackers because of high communication overheads. Therefore, we firstly define the concept of complete null space, with the property that no pollution packets can pass its verification. We then propose the idea of partial position detection and design an algorithm to construct short null keys. Secondly, we provide a short null keys based pollution detection scheme with network coding, which has lower overheads compared with the original null keys based pollution detection scheme in composing complete null space. Finally, rigorous theoretical proofs are given to analyze the security of the designed scheme.