Robust key generation from signal envelopes in wireless networks
A less expensive and more flexible solution to the problem of sharing secret keys between wireless nodes is to use the inherent randomness in the wireless channel between them as the source for extracting bits of the secret key between these nodes. We propose a new secret key distribution approach that utilizes the uniformly distributed phase information of channel responses to extract shared cryptographic keys under narrowband multipath fading models. Compared to existing approaches which only support pair wise key distribution, our scheme is highly scalable and can support efficient group key distribution. Various key distribution schemes are appraised to determine the level of security and connectivity. Simulated results show that key distribution exploiting channel phase has improved resilience against node capture.