Security Analysis and Improvement of Efficient ID-based Proxy Blind Signature Scheme

Proxy signature,allows that an original signer can delegate his signing authority to a proxy signer.In blind signature scheme,a signing messages are unknown to the signer,which makes the blind signature and the identity of the requester cannot be traced.By analyzing the ID-based proxy blind signature proposed by Chen Ling-ling et al..We point out that the proxy key in their scheme is insecure.And the signature can be traced.An improved scheme is proposed which overcomes the disadvantages of original scheme,and our new scheme is more efficient than their scheme.