A new proxy signature scheme with a semi-trusted third party based on Elliptic Curve Discrete Logarithm Problem

The design of new elliptic curve cryptosystem is still an interest to community of cryptography. In this paper, a proxy signature scheme with a semi-trusted third party based on Elliptic Curve Discrete Logarithm Problem (ECDLP) has been proposed. Authorisation mechanism is introduced to prevent the online original signer in this scheme. The semi-trusted third party's secret value in the proxy signature makes the scheme more secure. The scheme needs shorter time to generate proxy signature since it is based on ECDLP. We show that our proxy signature scheme with a semi-trusted third party satisfies the unforgeability, undeniability and misuse properties. Compared with the Liu et al.'s scheme, our scheme has the advantages of high security strength and short key length. To the best of my knowledge, it is the shortest proxy signature scheme with a semi-trusted third party. Copyright © 2013 Inderscience Enterprises Ltd.