高效的在线/离线代理重签名方案  

Efficient On-line/Off-line Proxy Re-signature Schemes

作　　者：杨小东[1] 王彩芬[1] 

机构地区：[1]西北师范大学数学与信息科学学院,兰州730070

出　　处：《电子与信息学报》2011年第12期2916-2921,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61063041);西北师范大学青年教师科研能力提升计划(NWNU-LKQN-10-22)资助课题

摘　　要：为了改善代理重签名的性能,该文提出在线/离线代理重签名方案。其基本思想是将重签名算法分成离线阶段和在线阶段。在签名消息到来之前,离线阶段进行重签名的大部分计算,并将这些运算结果保存起来;在签名消息到来时,利用离线阶段保存的数据能在很短的时间内生成消息的在线重签名。文中给出了在线/离线代理重签名方案形式化定义,在此基础上构造了具体实现的方案,并在随机预言模型下给出其安全性证明。该方案可将任意一个代理重签名方案转换为一个高效的在线/离线代理重签名方案。分析结果表明,新方案在效率上优于已有的代理重签名方案,在线重签名算法仅需要1次模减法运算和1次模乘法运算。To improve the performance of proxy re-signature schemes, the schemes of on-line/off-line prox）r re-signature are proposed in this paper. The main idea is to split the re-signing procedure into two phases： the off-line and on-line phases. Most of the computations are performed in the off-line phase before seeing the message to be re-signed. The results of this precomputation are saved and then used in the on-line phase when the message must be re-signed. On-line/off-line proxy re-signature schemes are used in a particular scenario where the proxy must respond quickly once the message to be re-signed is presented. Based on the formal definition of on-line/off-line proxy re-signatures, an efficient construction of on-line/off-line proxy re-signature is presented. It can convert any proxy re-signature scheme into a highly efficient on-line/off-line one. Security is proved in the random oracle model. Compared wirh the existing proxy re-signature schemes, the new scheme is more efficient in the communication cost and the computational cost. It needs one modular subtraction computation and one modular multiplication computation in the on-line re-signing generation algorithm.

关 键 词：代理重签名 在线/离线 变色龙哈希函数 随机预言模型 

分 类 号：TP309.7[自动化与计算机技术—计算机系统结构]