无可信PKG的盲签名方案的安全性分析及改进  

SECURITY ANALYSIS AND IMPROVEMENT FOR BLIND SIGNATURE SCHEME WITHOUT TRUSTED PKG

作　　者：李莎[1] 李虓[1] 何明星[1] 罗大文[1] 杜亚军[1] 

机构地区：[1]西华大学数学与计算机学院,四川成都610039

出　　处：《计算机应用与软件》2016年第2期307-309,325,共4页Computer Applications and Software

基　　金：国家自然科学基金项目(U1433130;61271413);四川省重点基金项目(SZD0802-09-1);西华大学重点实验室开放研究基金项目(S2jj2012-029)

摘　　要：无可信PKG的密码体制克服了基于身份的密码体制的密钥托管问题。针对何俊杰等人的无可信PKG的盲签名方案,详细分析其安全性,发现其方案不能抵抗敌手A_I伪造攻击。敌手A_I在无法获取用户的部分私钥和秘密值的情况下,对用户的部分公钥进行替代,可生成对任意消息的合法的盲签名。当用追溯算法时,仲裁方将断定该签名是PKG伪造的,诚实的PKG就会被敌手A_I陷害。为此,提出相应的改进方案,对验证等式做了相应变化,有效地防止了敌手A_I的公钥替代攻击。The eryptosystem without trusted PKG gets over the problem of key escrow of the identity-based cryptosystem. In this paper we analyse in detail the security of blind signature schemes without trusted PKG presented by He Jun-jie et al. , and find out that this scheme cannot resist the forgery attack of type one adversary A1. The adversary A1 substitutes user＇ s partial public key under the condition of unable to gain the partial private key and secret value of the user, and this can forge a legitimate blind signature on arbitrary message. When the trace algorithm is executed, the arbiter will decide that this signature is forged by the PKG, and the honest PKG is to be framed by adversary AI. Therefore, we propose an corresponding improved scheme, and make correlated change to the verification equation, thus effectively prevent the public key substitution attacks by adversary A1.

关 键 词：基于身份 盲签名 私钥生产中心 伪造攻击 替代公钥 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]