Privacy-Preserving Digital Rights Management based on Attribute-based Encryption

We present a privacy-preserving multiparty DRM scheme that does not need a trusted third party. Users anonymously buy content from content providers and anonymously execute it at content execution centers. The executions are unlinkable to each other. The license check is performed as part of the used ciphertext-policy attribute-based encryption (CP-ABE) and, thus, access control is cryptographically enforced. The problem of authorization proof towards the key center in an ABE scheme is solved by a combination with anonymous payments.