Key-Insulated Aggregate Proxy Signature

The proxy signature is one among significant cryptographic primitives that enables proxy signer sign on given message in support of original signer. Aggregate signature is another such primitive, which is a single compressed signature attained on combining different n (signatures; signers; messages). The former possesses applications involving distributed computing in which the allocation of rights is relatively common and the latter greatly reduces the communication bandwidth in multicast, group oriented communications. To keep the exposure of private keys minimum in signature schemes; keeping the benefits of both proxy and aggregate schemes, we construct the first efficient aggregate proxy signature scheme using key-insulated mechanism in the Identity-based framework. The constructed scheme, delivers tight secure reductions to Computational Difie-Hellman problem, since it is obtained without the use of Forking lemma. Also, the constructed scheme is efficient both computational as well communicational view point.