Traitor Tracing and Revocation for Secure Decoders in File Syncing-and-Sharing Service

Today, many cloud storage services have been available to small-to-medium business and individuals by file syncing-and-sharing (FSS) service. To meet the security requirement of FSS, we present a new architecture based on secure Player/Reader box with RBAC-compatible cryptosystem, which supports to access the encrypted data in the cloud, as well as traitor tracing and revocation mechanisms for pirate box. We improve a cryptosystem, called Partially-ordered Hierarchical Encryption (PHE) to realize this architecture. In this system, two security mechanisms, traitor tracing and revocation, are provided to support efficient digital forensics. The result of performance evaluation shows that our scheme is more efficient than the existing schemes with traitor tracing and revocation.