Analysis of a Secure Cooperative Channel Sensing Protocol for Cognitive Radio Networks

Cognitive radio (CR) has been introduced to allow unlicensed users, or better known as secondary users (SUs), to exploit underutilised licensed spectrum owned by the primary users (PUs). The SUs perform channel sensing to check the state of the PUs in order to use the channel without interfering with the PUs' activities. It is possible for malicious users or attackers to exploit channel sensing resulting in biased sensing decisions benefiting selfish SUs or attackers. In SIN 2011, a secure cooperative sensing protocol was proposed by Rifa-Paus and Gamgues to address this issue. In this paper, we study their protocol and discuss possible issues in the protocol, including the possibility of creating a rogue fusion centre and replaying session authentication. We also briefly examine the practical threats from more powerful adversanes capable of jamming the channels. We suggest several potential mitigations including use of well-established authenticated key exchange and standard entity authentication mechanisms.