A network coding method for channel signatures based key distribution

To enhance network security, we propose a secret key generation and distribution method for multihop wireless OFDM networks. In this method, the inherent physical features of wireless channel signatures, including randomness and reciprocity, are exploited to generate secret keys. In addition, a network coding approach is introduced for key distribution between a pair of transmitter and receiver in a multi-hop network. Our proposed protocol constructs the secret key from multiple branches at the source and forwards partial key information through separate paths to the destination using a simple and robust network coding operation. Under our protocol, cooperative relay nodes cannot decipher the key due to the partial information available, which provides a strong encryption capability for multi-hop systems. Mathematical analysis and excessive simulations demonstrate the high effectiveness of our proposed scheme.