A New Approach to Keep the Privacy Information of the Signer in a Digital Signature Scheme

In modern applications, such as Electronic Voting, e-Health, e-Cash, there is a need that

the validity of a signature should be verified by only one responsible person. This is opposite to

the traditional digital signature scheme where anybody can verify a signature. There have been

several solutions for this problem, the first one is we combine a signature scheme with an encryption

scheme; the second one is to use the group signature; and the last one is to use the strong designated

verifier signature scheme with the undeniable property. In this paper, we extend the traditional

digital signature scheme to propose a new solution for the aforementioned problem. Our extension is

in the sense that only a designated verifier (responsible person) can verify a signer’s signature, and

if necessary (in case the signer refuses to admit his/her signature) the designated verifier without

revealing his/her secret key is able to prove to anybody that the signer has actually generated the

signature. The comparison between our proposed solution and the three existing solutions shows

that our proposed solution is the best one in terms of both security and efficiency.