Fail-Stop Group Signature Scheme

Abstract

In this study, a fail-stop group signature scheme (FSGSS) that combines the features of group and fail-stop signatures to enhance the security level of the original group signature is proposed. Assuming that FSGSS encounters an attack by a hacker armed with a supercomputer, this scheme can prove that the digital signature is forged. Based on the aforementioned objectives, this study proposes three lemmas and proves that they are indeed feasible. First, how does a recipient of a digitally signed document verify the authenticity of the signature? Second, when a digitally signed document is under dispute, how can the group’s manager determine the identity of the original group member who signed the document, if necessary, for an investigation? Third, how can one prove that the signature is indeed forged following an external attack from a supercomputer? Following an attack, the signature could be proved to be forged without exposing the key. In addition, the ultimate goal of the group fail-stop signature scheme is to stop using the same key immediately after the discovery of a forgery attack; this would prevent the attack from being repeated.