SSDF protection in cooperative spectrum sensing employing a computational trust evaluation algorithm

A serious threat to cognitive radio networks which sense the spectrum in a cooperative manner is the transmission of false spectrum sensing data by malicious secondary nodes. This enforces the system to acquire authentication. Actually, the decision maker needs to determine the reliability or trustworthiness of the shared data. In this paper, the evaluation process is considered as an estimation dilemma on a set of evidence which is obtained from distributed cooperating nodes. Then, a MLE-based computational trust evaluation algorithm is proposed to determine the trustworthiness of each cognitive radio (CR) user´s data. The proposed procedure just uses the information which is obtained from the CR users without any presumptions about nodes reliability. Numerical results confirm the effectiveness of the algorithm in eliminating malicious nodes effects when 16% of cooperating nodes in the network are considered as malicious, and up to 20%, the algorithm are found to have a reasonable performance.