Experimental results on secret-key extraction from unsynchronized UWB channel observations

Wireless channel reciprocity can be exploited by two users willing to achieve confidential communications over a public channel as a common source of randomness for the generation of a secret key. In this chapter, the important issue of signal synchronization between the two users is discussed and a simple and practical solution is proposed to overcome this problem. The proposed scheme is tested with a real measurements campaign aimed at extracting secret-keys from the physical parameters of ultrawide bandwidth channels in an indoor scenario. The proposed solution is proved to be effective, as shown in the numerical results that provide an insight on the rate of agreement between the keys separately generated by the two users