An efficient privacy-preserving protocol for database-driven cognitive radio networks

Cognitive radio is regarded as a promising technology for remedying spectrum shortage and improving spectrum utilization. However, database-driven cognitive radio networks (CRNs) are vulnerable to a series of security attacks and privacy threats, especially the privacy breach of secondary users (SUs). In this paper, we propose an efficient privacy-preserving protocol to protect the identity and trajectory privacy of each SU and to prevent the database (DB) from tracing any SU. Besides, this paper also aims at improving the efficiency of authentication and channel allocation to offer the best connectivity to SUs wherever they are and at any time. Taking advantage of the elliptic curve cryptography technique, our protocol achieves the mutual authentication between SUs and base stations (BSs), which enhances the security of CRNs communication. Based on channel pre-allocation to BSs, our protocol reduces the latency of obtaining available channels for SUs. Moreover, our protocol exploits reputation to motivate SUs to be honest and thus increases the utilization of the limited spectrum resources. The results of security analysis show that our protocol provides strong privacy preservation for SUs that the DB cannot get the entire trajectory of any SU, even the DB colludes with all BSs. Furthermore, the results also show that the proposed protocol can resist various types of attacks. The results of performance evaluation indicate the efficiency of the proposed privacy-preserving protocol.