摘要
The focus of this paper is to design an efficient and secure solution addressing the semi trusted issue in proxy re-signature schemes, i.e., the proxy knows the re-signature key from user A to user B, so he is able to translate any signatures made by user A to user B, which damages the essential requirement （＂non-repudiation＂ property） of proxy re-signature schemes. In this paper, the authors first define the security model for threshold proxy re-signature scheme, and then propose two threshold proxy re-signature schemes based on Ateniese-Hohenberger＇s and Shao-Cao-Wang-Liang＇s approach.
基金
supported in part by the National Natural Science Foundation of China under Grant Nos. 61033014,60970110,60972034
the National 973 Program under Grant No.2007CB311201
