Abstract: The extensive threats in cognitive radio networks is detection of primary user signal. Cooperation among secondary users swell the performance of the system significantly. In cooperative sensing in hostile environments, intruder nodes send incorrect sensing results to the SBS and make the fusion center erroneously decides about the presence of the primary user. Here we proposed a novel active transmissions based algorithm with ECC for detecting such malicious SUs. This is the ?rst algorithm that can proactively detect malicious SUs, thereby preventing Cognitive Radio Networks from making incorrect sensing decisions. This helps in reducing the interference to Primary Users as well as increases the accuracy of sensing. Elliptic Curve Cryptography (ECC) is used for the security in the CR network. ECC key sizes are shorter than that of RSA keys, the length of the public key and private key is much shorter in elliptic curve cryptosystems. ECC reduces the throughput loss and provides security to the networks.

Keywords: Cognitive radio, cooperative spectrum sensing, Primary User Emulation (PUE), Elliptic curve cryptography (ECC).