Attribute-Based Ring Signatures

Ring signature was proposed to keep signer’s anonymity when it signs messages on behalf of a “ring” of possible signers. In this paper, we propose a novel notion of ring signature which is called attributebased ring signature. In this kind of signature, it allows the signer to sign message with its attributes from attribute center. All users that possess of these attributes form a ring. The identity of signer is kept anonymous in this ring. Furthermore, anyone out of this ring could not forge the signature on behalf of the ring. Two constructions of attribute-based ring signature are also presented in this paper. The first scheme is proved to be secure in the random oracle model, with large universal attributes. We also present another scheme in order to avoid the random oracle model. It does not rely on non-standard hardness assumption or random oracle model. Both schemes in this paper are based on standard computational Diffie-Hellman assumption.