An Efficient ID-Based Partially Blind Signature Scheme

A partially blind signature allows a signer to explicitly embed a pre-agreed common information into a blind signature without the loss of blindness property. It is an important technology in e-commerce. In ID-based public key setting, a user´s public key can be derived directly from his identity without access to public key certificate. It can simplify the key management process in traditional certificate based cryptosystem. To our knowledge, many partially blind signature schemes have been proposed till now. However, no ID-based partially blind signature scheme has been proposed. Recently, Chow et al. first proposed an ID-based partially blind signature scheme based on bilinear pairings, but it isn ´t very efficient. In this paper, we improve C how et al´s scheme and present a new ID-based partially blind signature scheme. We also analyze the security and efficiency of the proposed scheme. We show that our scheme is more efficient and needs less computation cost than Chow et al.´s scheme and is provably secure under the random oracle model.