Abstract: In this paper, we propose an identity-based ring signature scheme from bilinear pairings which fulfils perfectly the security requirements of ring signature. Our scheme can be considered as a simplified group signature with no group setup procedure, and no revocation mechanism against signer`s anonymity, thus signer`s privacy is guaranteed. As compared with Zhang`s scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced from O(n) to O(1).