A Designated Verifier Proxy Signature Scheme with Fast Revocation without Random Oracles

In a designated verifier proxy signature scheme, proxy signature is issued for a designated receiver and only he/she can validate the signature. The fast revocation of delegated rights is an essential issue of the proxy signature schemes. In this paper, we present a designated verifier proxy signature scheme with fast revocation that has provable security in the standard model. In the our proposed scheme, we use of an on-line partially trusted server named SEM and the SEM should check whether a proxy signer signs according to the warrant or he/she exists in the revocation list. Additionally, the proxy signer must cooperate with the SEM to produce a valid proxy signature. We also propose the provable security of our scheme is based on the Gap Bilinear Diffie- Hellman (GBDH) intractability assumption and we will show that the proposed scheme satisfies all the security requirements for a proxy signature.