An ID-based blind signature from bilinear pairing with unlinkability

Besides the general features of the digital signature, blindness and unlinkability are two the most important properties of blind signature. The latter means that after the signature finished, the signer cannot link a valid message-signature pair and the protocol information in signature. In this work, we first review an identity-based blind signature scheme from bilinear pairing and a security flaw of this scheme. Subsequently, we present an improved scheme that avoid the attack of linkability of this blind signature scheme. Finally, we prove that the so-called linkability attack can be resisted in improved scheme.