Attribute-based ring signatures: Security analysis and a new construction

In this study, we review attribute-based ring signature schemes. Our proposal presents two contributions; the first one is security analysis of Wenqiang et al.´s scheme in 2009 by presenting an attack in which we show that their scheme is forgeable. The second contribution is an efficient attribute-based ring signature scheme with constant size and constant number of pairing operations. Our scheme is unconditionally anonymous and unforgeable in the standard model. The security of our proposal is based on Static Diffie Hellman (SDH) problem. Compared with the existing attribute-based ring signature scheme with constant size, the length of the signature and the pairing operations in our scheme are decreased by 1/3 and by 1/4, respectively. Thus, the efficiency of signing and verifying is improved in our proposal.