Abstract: To solving the threat to the primary user emulation (PUE) in cognitive radio networks, this paper presented a security scheme based on HASH matching technique. In this scheme, when primary user network was working, we added the HASH original data to the data sent by primary user base station, firstly secondary users used HASH funcoon to calculate those received original data,and then compared results with predistribution HASH values. Successful matching proved that the message of primary user emergency was true. This scheme made the best of the HASH characteristic of quickly calculating,which guaranteed timely spectrum handoff of secondary users and avoided interfering with primary user. The security of this scheme was guaranteed by the irreversible of one-way HASH function. The detail of the scheme was presented in this paper. Comparing with relevant schemes,it provides safety,efficiency and feasibility, and can effectively solve primary user emulation problem in cognitive radio networks.

Key words: Cognitive radio, Primary user emulation (PUE) , Network security, HASH