A Practical Privacy Preserving Protocol in Database-Driven Cognitive Radio Networks

Cognitive radio technique is regarded as a promising way for allowing secondary users (SUs) to access available channels without introducing the interference to the primary users (PUs). However, database-driven cognitive radio networks (CRNs) are facing a series of security and privacy threats, especially the privacy breaches of SUs. To address this issue, this paper proposes a practical privacy-preserving protocol for database-driven CRNs that allows SUs to get the available channels in their vicinity efficiently while protecting their privacy. Our protocol takes advantage of modular square root technique to verify the identity of a SU and enables a legitimate SU to obtain the available channel without leaking its privacy. By prefetching channels, our protocol reduces the latency of obtaining available channels for SUs. Besides, the proposed protocol provides strong privacy preservation that the database cannot trace any SUs and get nothing about location or identity information of SUs, even the database colludes with all base stations. The results of security analysis and performance evaluation indicate the feasibility and practicality of the proposed privacy-preserving protocol.