The realization of key extraction based on USRP and OFDM channel response

The reciprocity of the wireless and the randomness of channel characteristic is the basis of physical layer key generation technology based on the channel. The complete key generation technologies include five steps that channel probing, channel feature extraction, quantification, reconciliation and privacy application. There are many theories and simulation prove the feasibility of key extraction and in this paper, the first four steps of key extraction are realized by using MIMO-OFDM system established by the USRP radio devices. This paper summarizes the physical layer key generation process, and introduces the method of extracting key from different literatures is used to realize the key extraction, so as to provide an important reference for further research on key generation technology.