A Modified Anonymous Proxy Signature with a Trusted Party

In 2002, Shum and Wei proposed a anonymous proxy signature, that is, no one can determine the identity of the proxy signer only from the proxy signature, and a trusted party can reveal the proxy signerpsilas identity if needed. However, in 2005, Narn-Yih Lee *, Ming-Feng Lee showed that the Shum-Wei scheme cannot keep the property of the strong unforgeability, and the original signer can generate valid proxy signatures. On the base of that, so we present a modified anonymous proxy signature with a trusted party, which adds the proxy signer private key in the proxy signature key, and the aim is to avoid the original signerpsilas forging proxy signature. Finally, we give the simple security analysis and conclude our scheme is unforgeable and secure.