A Survey on Secret Key Extraction Using Received Signal Strength in Wireless Networks

Secure wireless communications typically rely on secret keys, which are difficult to establish in an ad hoc network without a key management infrastructure. The channel reciprocity and spatial decorrelation properties can be used to extract secret key, especially in a Rayleigh fading channel. But the intervention of intermediate objects between the communication nodes reduces the strength of the secret key generated through such methods. Furthermore, the impact of small fluctuations also reduces the bit matching rate of such key agreement methods. This paper is based on the survey conducted on secret key generation from Received Signal Strength (RSS). By consider ing uniqueness property of RSS as base, various authors have proposed different methods for secret key extraction. Due to use of RSS for key extraction the existing systems suffer from predictable filter response at random period. The existing system also faces signal fading and drop in RSS because of intermediate object. By this survey we specify that even after generating high entropy bits for key extraction, there are considerable drawbacks in extracted key du e to intervention of intermediate objects and remarkable fading and drop in RSS