A Trust-Based Adaptive Authentication Scheme for Space-Air-Ground Integrated NOMA System

The emerging cooperative non-orthogonal multiple access (C-NOMA) technique is expected to be integrated in future space-air-ground integrated networks (SAGIN) to improve network capacity and achieve global coverage. However, the limited resource, untrusted NOMA relays and openness channels of SAGIN would inevitably encounter severe data security and privacy violation problems. Many secure access authentication schemes have been developed for SAGIN either by employing physical layer authentication methods for NOMA communication or by utilizing post-quantum cryptographic mechanism for orthogonal multiple access networks. In this regard, we propose an adaptive access authentication scheme by considering both trusted and untrusted NOMA relays to resist quantum attack for C-NOMA communication in SAGIN based on the Number Theory Research Unit scheme. The experimental results show that our scheme can achieve high performance in terms of communication latency and network capacity while guaranteeing communication security for SAGIN NOMA systems.