An Identity-Based Proxy Signature from Bilinear Pairings

Currently, ID-based PKC has attracted much attention and got many achievements. Proxy signature allows an original signer to delegate his private key to a proxy signer to sign some message on behalf of the original signer. We present a ID-based proxy signature in this paper. The scheme is relatively efficient as there is no pairing computation during the Delegation and PSign phases. It is secure against existential forgery under adaptive chosen message and identity attack under the random oracle model. Its security can be reduced to the hardness of CDHP.