A Proxy Signature Scheme without Using One-way Hash Functions

Abstract

A new proxy signature scheme without using one-way hash functions is proposed. This scheme has the following advantages. This new scheme does not need one-way hash functions to integrate warrants into the proxy certificate. Therefore, the overall security of this proxy signature scheme is only based on the discrete logarithm problem. This new scheme also removes the requirement of secure channels while the most proposed proxy signature schemes need. Our scheme provides the powerful specifiable function for the proxy details with the help of warrants. Moreover, the new scheme supports a fair protection both for the original and proxy signers.