A secure identity-based proxy multi-signature scheme

In a proxy multi-signature scheme, a designated proxy signer can generate the signature on behalf of a group of original signers. To our best knowledge, most of existing proxy multi-signature schemes are proposed in public key infrastructure setting, which may be the bottleneck due to its complexity. To deduce the complexity, several proxy multi-signature schemes are proposed in the ID-based setting. However, no formal definitions on ID-based proxy are proposed until now. To fill the gap, this paper proposes the formal definition. Furthermore, we present a proven secure ID-based proxy multi-signature scheme, which is more efficient than existing schemes in term of computational cost.