Trust-Aware CUEA Detection and Mitigation for Secure Spectrum Handoff in CRNs

Cognitive Radio (CR) is an intelligent wireless communication technology that improves spectrum efficiency by detecting and utilizing unused licensed frequency bands in real time.Traditional spectrum allocation follows a fixed, regulatory approach, which often results in large portions of the licensed spectrum remaining idle despite being reserved for specific users.These temporarily unused bands are known as spectrum holes or white spaces.CR solves this problem by allowing smart devices to sense spectrum availability and access idle bands in a dynamic and opportunistic manner, while ensuring that no harmful interference is caused to primary or licensed users.Selecting the most suitable spectrum band according to availability, access feasibility, and Quality of Service (QoS) requirements is a key factor in maintaining strong network performance.For primary and secondary users to cohabit peacefully in Cognitive Radio Networks (CRNs), spectrum assignment and handoff are crucial processes.However, the constantly changing and unpredictable nature of spectrum availability introduces multiple challenges, especially related to interference control, security threats, and diverse QoS needs across applications.Therefore, to keep networks stable, dependable spectrum management strategies are needed.In this study, we identify a security vulnerability called the Cognitive User Emulation Attack (CUEA), where attackers imitate legitimate cognitive users during spectrum handoff to gain unauthorized access.To defend against this, we propose a secure spectrum handoff strategy that includes a coordinating cognitive user tasked with continuously observing network user behavior.This coordinating user evaluates activity patterns, assigns trust scores, and differentiates between genuine and malicious users, reducing the risk of false authentication.MATLAB simulations validate the approach, showing improved attack detection accuracy, higher throughput, lower transmission delay, and better overall network reliability during spectrum handoff, making CRNs more secure and efficient.