A traceable and revocable decentralized multi-authority privacy protection scheme for social metaverse

Intelligent identification of close friends is the mainstream approach to protect users' multi-dimensional data in the social metaverse. It provides a fine-grained matching service for users. However, users enjoy these benefits at the cost of leaking personal multi-dimensional data. The existing social metaverse-based intelligent identification of close friends privacy protection models typically use centralized mechanisms. This will limit users' control over their data and make them vulnerable to privacy leakage and data misuse. To address these problems, this paper proposes a traceable and revocable decentralized multi-authority privacy protection scheme (TRDM) for social metaverse. The scheme establishes multiple authority centers based on users' multi-dimensional data, overcoming single point of failure and performance bottlenecks. In addition, TRDM partially hides access policies and supports multi-dimensional attribute access control in social metaverse environment. By introducing leaf node values of binary trees, TRDM achieves the traceability and completes the revocation of malicious users by updating part of the ciphertext. Security analysis and experiments show that TRDM satisfies the requirement of static security under the random prediction model and has better performance in the revocation of malicious users.