Secure proxy multi-signature scheme in the standard model

Abstract

In electronic world, proxy signature is a solution of delegation of signing capabilities. Proxy multi-signature schemes allow a proxy signer to generate a proxy signature on behalf of two or more original signers. However, the security of the known proxy multi-signature schemes is proven in the random oracle which does not imply security in the real world. In this paper, we present a proxy multi-signature scheme in the standard model. The size of a proxy multi-signature is independent of the number of the original signers. Our scheme is existentially unforgeable against chosen message attack and chosen warrant attack based on the hardness of the well known CDH problem in the standard model. © 2008 Springer Berlin Heidelberg.