CAJ | 학술논문

对两个基于辫群的代理签名方案进行了分析,发现它们并不满足不可伪造性.第一个方案中不能抵抗原始签名人改变攻击,在第二个方案中任何攻击者可以伪造一个有效的代理签名,在该签名中,代理签名者以及消息可以任意指定.根据上述缺陷,提出一个改进的强代理签名方案,新方案在不增加计算复杂性的前提下,保证了签名的安全性,同时代理授权过程中还增加了不需要安全通道的性质.
대량개기우변군적대리첨명방안진행료분석,발현타문병불만족불가위조성.제일개방안중불능저항원시첨명인개변공격,재제이개방안중임하공격자가이위조일개유효적대리첨명,재해첨명중,대리첨명자이급소식가이임의지정.근거상술결함,제출일개개진적강대리첨명방안,신방안재불증가계산복잡성적전제하,보증료첨명적안전성,동시대리수권과정중환증가료불수요안전통도적성질.
Analysis shows that two proxy signature schemes based on braid groups are insecure: the first scheme cannot resist the original signer' s change attack; in the scheme of second, any antagonist can successfully forge a valid proxy signature scheme, which the antagonist can designate any proxy signer and messages. Later, a new proxy signature scheme was proposed. Analysis shows that the proposed scheme satisfies all security requirements; what' s more, no security channel is in need in the communication of the original signer and the proxy signer.