Practical verifiably encrypted signatures based on discrete logarithms

Abstract

AbstractBecause the discrete‐log‐based signature scheme on finite groups can be adapted to elliptic curves most efficiently, it has been developed widely in the mobile Internet. However, how to verifiably encrypt such signatures is a long‐lasting open problem. In this paper, we present the first verifiably encrypted discrete‐log signature scheme based on undeniable signatures, whose security depends on the discrete logarithm problem and the computational Diffie–Hellman problem in the random oracle model. Our security proof is under a strong security model against three types of inside adversaries with more powers. The proposed scheme can be deployed directly in the current Internet environment; nothing more than each party has an ElGamal key pair on a common finite group. Copyright © 2017 John Wiley & Sons, Ltd.