An Energy Efficient Access and Handover Authentication Scheme for 6G Satellite-Terrestrial Integrated Network

6G Satellite-Terrestrial Integrated Network (STIN) extends connectivity services globally, attracting an increasing number of users to access the Internet with its advantages of wide coverage, high speed, and large capacity. However, the complex communication environments, such as link exposure and high dynamics of satellites in the network, pose challenges to designing authentication schemes that are applicable to 6G STIN. Although researchers have proposed many authentication schemes for 6G STIN, most of them have only focused on access authentication, which cannot guarantee the stability of subsequent communications. A few schemes have considered providing seamless services through handover authentication, but they still face issues such as security vulnerabilities and high energy consumption. To tackle these issues, this paper proposes an energy efficient authentication scheme for 6G STIN, capable of achieving mutual authentication between entities and negotiating a secure session key. Additionally, it designs a handover mechanism that is more suitable for 6G STIN and supports handover authentication for multiple users. Through security analysis, our scheme is proven to withstand various attacks, and its security is further verified using the ProVerif tool. Performance analysis shows that our scheme has lower authentication latency and communication overhead, while reducing energy consumption and ensuring security.