A Novel Theoretical Analysis of Cooperative Spectrum Sensing Reliability in the Presence of Malicious Users in Nigerian Secondary Spectrum Markets

Cooperative spectrum sensing improves detection performance by aggregating sensing reports from multiple cognitive radio nodes, but introduces a security vulnerability to falsified sensing reports from malicious users attempting to distort the cooperative decision or exploit spectrum access opportunistically. The reliability of cooperative sensing under malicious user threats in the specific regulatory and market structure of Nigerian secondary spectrum frameworks requires original theoretical analysis. This doctoral study develops a novel theoretical analysis of cooperative spectrum sensing reliability under Byzantine attack models in Nigerian secondary spectrum market contexts, deriving optimal fusion rule designs and malicious node detection algorithms with provable performance guarantees. An original attack model is formulated that captures the incentive structure of malicious users in a Nigerian secondary spectrum market where spectrum access rights generate quantifiable economic value, enabling adversarial behavior parameterization more realistic than existing attack models in the literature. Theoretical analysis derives the optimal linear fusion rule for cooperative sensing under bounded adversarial falsification, characterizing the sensing reliability achievable as a function of the malicious user proportion, falsification strategy parameters, and network size. An original reputation-based malicious node exclusion algorithm is proposed, with theoretical guarantees on detection delay as a function of reporting round count and attack intensity. Simulation calibrated to Nigerian spectrum occupancy statistics demonstrates that the proposed framework maintains cooperative sensing reliability above 0.95 detection probability even when 30% of cooperating nodes are malicious, compared to a degradation to 0.61 for conventional majority voting under identical conditions. Keywords: cooperative spectrum sensing, Byzantine attack, cognitive radio, secondary spectrum market, Nigeria.