A Traitor Tracing and Access Control Method for Encrypted 3D Models Based on CP-ABE and Fair Watermark

With the rapid development of the metaverse, massive amounts of 3D data are created and outsourced in the cloud, and ciphertext policy attribute-based encryption (CP-ABE) is widely used in fine-grained access control to achieve secure outsourced data sharing. However, the prominent security risk is due to the fact that authorized data users may later become traitors and illegally redistribute the 3D models to the public. To protect the rights of the creator, a traitor tracing and access control method for encrypted 3D models is proposed using CP-ABE and fair watermark to meet the security needs in the metaverse. First, a commutative watermark/encryption method based on the orthogonal operation domain is designed, and the 3D model is encrypted by CP-ABE. Then, a fair watermark protocol protects the rights of the parties. Finally, the blockchain acts as a trusted third party and records the authentication information for traitor tracing. The experimental results demonstrate the feasibility and safety of the proposed method.