On-line/Off-line Threshold Proxy Re-Signatures  

作　　者：YANG Xiaodong WANG Caifen ZHANG Lei QIU Jianbin 

机构地区：[1]College of Computer Science & Engineering, Northwest Normal University

出　　处：《Chinese Journal of Electronics》2014年第2期248-253,共6页电子学报（英文版）

基　　金：supported in part by the National Natural Science Foundation of China(No.61262057,No.61063041,No.61163038);the Young Teachers’Scientific Research Ability Promotion Program of Northwest Normal University(No.NWNU-LKQN-10-22)

摘　　要：To improve the performance of threshold proxy re-signatures, the notion of on-line/off-line threshold proxy re-signatures is introduced. The bulk of re-signature computation can be done in the off-line phase before the message arrives. The results of this pre-computation are saved and then utilized in the on-line phase once a message to be re-signed is known. Based on any threshold proxy re-signature scheme and a threshold version of chameleon hash function, we present a generic on-line/off-line threshold proxy re-signature scheme that can convert any existing secure threshold proxy re-signature scheme into an on-line/off-line one. The on-line phase of our scheme is efficient: computing a re-signature share requires one round of communication, two modular additions and one modular multiplication. Our scheme is provably secure under the discrete logarithm assumption without random oracles.Moreover, our scheme can achieve robustness in the presence of n/3 malicious proxies.To improve the performance of threshold proxy re-signatures, the notion of on-line/off-line threshold proxy re-signatures is introduced. The bulk of re-signature computation can be done in the off-line phase before the message arrives. The results of this pre-computation are saved and then utilized in the on-line phase once a message to be re-signed is known. Based on any threshold proxy re-signature scheme and a threshold version of chameleon hash function, we present a generic on-line/off-line thresh- old proxy re-signature scheme that can convert any ex- isting secure threshold proxy re-signature scheme into an on-line/off-line one. The on-line phase of our scheme is ef- ficient： computing a re-signature share requires one round of communication, two modular additions and one mod- ular multiplication. Our scheme is provably secure under the discrete logarithm assumption without random oracles. Moreover, our scheme can achieve robustness in the pres- ence of [n/3] malicious proxies.

关 键 词：ON-LINE/OFF-LINE Threshold proxy re- signature Chameleon hash function Standard model Ex- istential unforgeability. 

分 类 号：TP309[自动化与计算机技术—计算机系统结构]