Cooperative Impersonation in Angle-Based Physical Layer Authentication

We investigate cooperative impersonation jamming on angle-based physical layer authentication (PLA) within 6G systems using hybrid antenna arrays. PLA leverages angle-ofarrival (AoA) information to authenticate user equipment, but remains vulnerable to sophisticated jamming where multiple adversaries cooperate. We extend previous research by formulating a comprehensive model of PLA that integrates hybrid arrays and by developing optimized jamming strategies that consider energy and information constraints. Our results show that analog arrays are more vulnerable to cooperative jamming than hybrid arrays. Additionally, the combiner design in the hybrid array, along with the energy and information constraints on jamming strategies, significantly influences the success of jamming. By identifying vulnerabilities in PLA and studying effective countermeasures, this work contributes to advancing physical layer authentication in 6G systems.