Seeking Justice: Lapsed reputation-based cooperative spectrum sensing with lasting trusted nodes assistance

Cognitive radio (CR) is an enabling technology that promises to bring about remarkable improvement in spectrum utilization. To deal with the complicated wireless environment, cooperative spectrum sensing (CSS) has been proposed to take advantage of the spatial diversity in cognitive radio networks (CRNs). The data fusion technique is crucial to the security of CSS. Some reputation-based secure schemes have been proposed recently to confront the attack of malicious users. However, the existing schemes cannot remain robust when a large number of malicious users are present with complicated attack patterns. In this paper, we propose a lapsed reputation-based CSS scheme with lasting trusted nodes assistance (LR-LTNA), which has two innovative mechanisms. The lapsed reputation (LR) aims at alleviating the influence of the previously accumulated reputation value, while the lasting trusted nodes assistance (LTNA) focuses on ensuring the correctness of global decision continuously. These two mechanisms are able to treat all of the users more reasonable and keep CSS from being manipulated. Simulation results substantiate the effectiveness and robustness of the proposed scheme.