A Proxy Partially Blind Signature Scheme with Proxy Revocation

One of the most common problems of proxy blind signatures is the constant privilege abuse of the signers. In 2008, Liu et al. proposed a proxy signature scheme capable of revoking proxy privileges. In this method, the original signer can terminate the proxy privilege at any time without needing to go through a commonly trusted third party. However, this scheme is unable to provide untraceability, and is vulnerable to counterfeit signature attacks. This study reviews Liu et al.´s scheme and its security loopholes, and proposes a proxy partially blind signature scheme. The proposed scheme not only retains the revocation functions in Liu et al.´s approach, but also meets the security requirements of proxy blind signatures.