A Traceable Continuous Authentication Scheme for Avatars in Large-Scale Commercial Activities

Metaverse allows users to immersively interact with millions of partners, breaking through the constraints of the physical world. To ensure the traceability of malicious avatars, provers in large-scale commercial activities need to periodically submit identity parameters to the verifier as interaction evidence, imposing a disastrous communication and storage burden on both parties. In this article, we propose a traceable and efficient continuous authentication scheme for large-scale avatars. First, we construct a continuous authentication framework, where the prover’s device locally checks its manipulator to submit the starting and ending identities as interaction evidence. Second, we propose a transitive signature scheme with path verifiability to ensure the relevance and unforgeability of the starting and ending identities. Finally, we design a traceable authentication protocol based on the proposed signature scheme to reduce communication and storage costs while guaranteeing traceability. Security analysis shows that the protocol not only defends against the attacks of device hijacking and false accusations but also supports virtual-to-physical tracking. Extensive evaluations show that the communication cost and storage costs are reduced by 95.97% and 98.35%, respectively, which can be used for avatar authentication and tracking in large-scale commercial activities.