Dynamic Secret Key Generation Exploiting Ultra-Wideband Wireless Channel Characteristics

To guarantee a secure wireless communication between any two transceivers, the shared secret key is a requirement. Communication parties need to encrypt the message with the key to impede an adversary's eavesdropping. By exploiting Ultra-wideband (UWB) wireless fading channels as a source of common randomness, two transceivers with correlated observations can generate secret keys with information-theoretical security. The state of the art of existing works, however, has neglected to consider efficient channel probing. In this paper, we define a channel probing factor to adaptively change probing interval for obtaining more correlated measurements at the endpoints of wireless communicating link. We use multipath relative delay of UWB channel to generate secret keys. Simulation results show that this dynamic secret key generation mechanism extracting multipath relative delay can achieve good performance in terms of secret key generation rate, key randomness and key-mismatch probability, especially key-mismatch probability compared with received signal strength (RSS)-based method and our prior approach. Furthermore, security analysis is also provided to validate feasibility of the scheme.