Decentralized Anonymous Authentication With Fair Billing for Space-Ground Integrated Networks

The space-ground integrated network (SGIN) has attracted growing attention due to its advantages of high-capacity, low-latency and global coverage. To guarantee the security requirements of SGIN, anonymous authentication is an essential approach to addressing severe threats such as unauthorized access and impersonation attack, while payment is another common method in service-oriented applications in order to encourage companies to participate and also prevent insider attackers from enjoying services without paying. Existing anonymous authentication protocols for SGIN either require users to involve in heavy computation especially in dynamic scenarios, or do not consider cross-domain authentication. In this paper, we first introduce the concept of cross-company satellite services, and then address the cross-domain authentication and billing issues in SGIN, i.e., we propose a decentralized anonymous authentication scheme supporting fast handover and also achieve fairness for the billing procedures. To reduce the authentication delays, the authentication process is delegated from ground to satellites, such that users can arbitrarily switch the satellite networks belonging to different companies. Specifically, users can be anonymously authenticated by showing the knowledge of a secret bound with a randomized verifiable credential and connect to different satellite networks through a fast handover authentication protocol building on a blockchain. Even all companies collude, they cannot forge a valid identity credential and access records for a user. In addition, we provide a fair billing mechanism that can prevent malicious users and greedy satellite companies from manipulating the network accessing fees based on a well-designed smart contract. Finally, we demonstrate that the proposed scheme is secure and efficient through security analysis and performance evaluation.