TOWARD SECURE AND LIGHTWEIGHT ACCESS AUTHENTICATION IN SAGINS

Space-air-ground integrated networks (SAGINs) allow mobile nodes to gain access to the Internet anywhere and at any time, which has significantly broadened the communication coverage all over the world. Different from other heterogeneous networks, SAGINs have the characteristics of dynamic network and wide coverage, which make it vulnerable to various malicious attacks. To improve the security of SAGINs, researchers are facing many sophisticated challenges, in which access authentication is the primary problem to be solved because is mainly used to prevent illegal nodes from accessing SAGINs for network services. Therefore, it is crucial to design a secure and lightweight access authentication scheme for SAGINs. In this article, we propose an identity-based mutual authentication scheme (IMAS), which consists of three segments and five procedural phases. Multicast communication is first introduced in access authentication for re-authentication message transmission, which can greatly reduce authentication delay and signaling overhead during handover. Our further qualitative analysis shows that IMAS has proper security characteristics which can meet various security requirements. In addition, from the perspective of performance evaluation, IMAS has outperformed the existing schemes especially when mobile nodes change their access points frequently and need to be re-authenticated for accessing requests.