Securing Collaborative Authentication: A Weighted Voting Strategy to Counter Unreliable Cooperators

Collaborative physical layer authentication (CPLA) is a promising alternative, addressing common single-point failure issues in centralized authentication systems through its unique architecture. However, the necessary involvement of multiple parties increases the risk to collaborative systems, particularly from hostile cooperators, significantly impacting the performance of CPLA. In existing CPLA approaches, the most common strategy to combat malicious cooperators attacks is to select the best collaborative combination. This strategy achieves the customization goal by excluding hostile-minded devices. However, processing a non-fixed search space typically demands a substantial investment of time and resources. As a remedy, we propose a decision-level-based CPLA scheme with a weighted voting mechanism. Our scheme aims to implement streamlined and effective dynamic management of cooperators to ensure that multi-directional information provides positive effects on authentication. Specifically, we conduct a two-stage performance appraisal of all cooperators. To measure the trustworthiness of cooperators, an impression-driven reliability evaluation scheme is developed. We analyze the riskiness of individual cooperators to prevent centers from falling into cognitive bias. Finally, we validate the feasibility of the scheme. The results demonstrate that, in a scenario where 50% of participants are malicious, our approach achieves an accuracy improvement of 2.96% to 3% compared to other dynamic weighted voting schemes. The robustness and stability of the proposed CPLA scheme outperform the benchmark schemes.