无可信中心的可验证门限代理签名方案  

Secure(t,n) Threshold Proxy Signature Scheme Without a Trusted Party

作　　者：闫德勤[1] 赵洪波[1] 

机构地区：[1]辽宁师范大学计算机与信息技术学院,大连116029

出　　处：《计算机科学》2009年第7期82-84,共3页Computer Science

基　　金：国家自然科学基金(No.60372071);辽宁省教育厅高等学校科学研究基金(2004C031);辽宁师范大学校基金资助

摘　　要：提出了一个安全的门限代理签名方案。合谋攻击是指在不知道任何有效的门限代理签名的情况下,恶意代理成员人数大于或等于门限值时,他们能合谋重新构造代理群的秘密多项式函数,得到代理群的秘密参数,从而可以伪造其他代理成员的代理签名。以往方案大部分都是需要可信中心的,这样可信中心往往就会成为被攻击对象。提出的新方案能抵抗合谋攻击,任意t个人合作仍然无法知道其他代理人的秘密参数,也就无法伪造其他代理签名人的签名。还能满足门限代理签名的性质,且针对t个成员可能的恶意代理原始签名人签名的问题,由原始签名人两次授权来解决,这只需要维护签名生成者和原始签名人之间的一条安全信道。根据代理签名不能辨认代理签名人身份。每个参与者的公?私钥以及群公钥由参与者共同协商,无须可信中心参与,避免了对可信中心的攻击和成员之间的欺骗,使得安全性级别更高。A secure threshold proxy signature scheme was proposed. Conspiracy attack,that is,any t（t is threshold value） or more malicious proxy signatures may work together to reconstruct the secret polynomial of the proxy group and derive the secret keys of other members in the proxy group, consequently they can impersonate some other proxy signers to generate a valid threshold proxy signature. A large number of the schemes which were proposed require trusted party. So the trusted party becomes the attacked part. The proposed scheme can withstand the conspiracy attack, arbitrarily signers of t still can＇t know the secure keys of other members in the proxy group, so they can＇t impersonate some other proxy signers to generate a valid threshold proxy signature. Furthermore, with regard to t of malicious signers impersonate the original signer, the original signer uses the second empower to solve, which only needs one secret channel between the original signer and the generation signer. It cannot distinguish the proxy signers by proxy signatures. In the scheme each participant＇ s public key and private key and the group public key are negotiated among all participants with no trusted party required. We shall try to avoid attacking the trusted party and the cheating between proxy signers, the security of this scheme is more efficient than other schemes.

关 键 词：密码学 数字签名 门限代理签名 无可信中心 合谋攻击 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]