A Certificateless Encryption-Based Authentication Protocol for Low Earth Orbit Satellite Network

In this letter, a novel access and handover authentication scheme is proposed for Low Earth Orbit (LEO) satellite networks, aiming to achieve lightweight computation, privacy preservation, and seamless secure handover for massive sensor users. Different from traditional certificate-based and pairing-dependent authentication mechanisms, the proposed scheme is constructed on certificateless cryptography, which eliminates expensive bilinear pairing operations and avoids the complex certificate management overhead in traditional public-key systems. Meanwhile, it adopts lightweight elliptic curve point addition to further lower computational burden and adapt to the limited on-board computing resources of LEO satellites. To tackle the severe signaling storm and frequent handover dilemma caused by massive, densely deployed sensor terminals, a location-aware, user-grouping-based collaborative handover authentication protocol is specifically designed. The proposed scheme rigorously satisfies essential security properties, including mutual authentication, anonymous identity privacy, known-key security, and master key forward secrecy. Simulation results verify that the proposed protocol achieves superior security performance and remarkably reduces signaling interaction overhead. In the evaluated simulation setting, the proposed mechanism achieves up to 69.81% improvement in handover success rate compared with the standalone handover scheme under high-density access conditions.