CAJ | 학술논문

2005年,Hwang等提出了一个新的(t,n)门限代理(c,m)门限签名方案.在该方案中,只有n个原始签名者中的t或多于t个合作才能授权给m个代理签名者组成的代理群,同时,只有c或多于c个代理签名者合作才能产生门限代理门限签名.与其他门限多代理多签名方案相比,该方案的优点是原始签名者和代理签名者的利益受到公平的保护.但指出Hwang方案存在内部攻击,即在对一个消息的正常签名中,恶意的内部成员能伪造出另一个消息的有效签名.进一步,在分析攻击原因的基础上给出了两种改进方案.
2005년,Hwang등제출료일개신적(t,n)문한대리(c,m)문한첨명방안.재해방안중,지유n개원시첨명자중적t혹다우t개합작재능수권급m개대리첨명자조성적대리군,동시,지유c혹다우c개대리첨명자합작재능산생문한대리문한첨명.여기타문한다대리다첨명방안상비,해방안적우점시원시첨명자화대리첨명자적이익수도공평적보호.단지출Hwang방안존재내부공격,즉재대일개소식적정상첨명중,악의적내부성원능위조출령일개소식적유효첨명.진일보,재분석공격원인적기출상급출료량충개진방안.
Hwang et at,have proposed a new threshold-proxy threshold-signature scheme in 2005.In this scheme,only any t or more original signers of n original signers can cooperatively authorize a proxy group of m proxy signers and then only c or more proxy signers can cooperatively generate threshold-proxy threshold-signature.Compared with other threshold multi-proxy multi-sig-nature,this scheme has the advantage of providing the fair protection for the original and proxy groups.Unfortunately,this paper points out that Hwang's scheme is vulnerable to insider attack.That is,malicious inside members can forge a threshold-proxy threshold-signature for a message while participating in a normal message signing process.Furthermore,this paper proposes two improved schemes on the base of analyzing the insider attack.