Secret key generation exploiting Ultra-wideband indoor wireless channel characteristics

Existing algorithms of secret key generation from Ultra-wideband (UWB) channels mostly exploited received signal strength to extract secret bits, however, this method is limited in key match probability. To investigate the issue, an efficient secret key generation mechanism using multipath relative delay is developed. Furthermore, a statistical characterization of UWB channels for a Chinese residential scenario is studied to simulate the proposed scheme. Simulation results demonstrate that our mechanism can achieve better performance in terms of common secret bit generation compared with the conventional method using received signal strength as a common random source, and the number of multipath proportionally affects key generation rate and key-mismatch probability. Additionally, for the first time, we verify key generation mechanism in both line-of-sight (LOS) and non-line-of-sight (NLOS) UWB channels. The results indicate that communicating transceivers have a slightly lower key-mismatch probability in NLOS condition than in LOS condition, as NLOS channels can provide a larger number of multipath. Copyright (c) 2014 John Wiley & Sons, Ltd.