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...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.展开更多
This paper defines the security notion for Certificateless Threshold Signatures （CLTHS）. Different from the adversarial model defined by Wang, et al. （2007）, our definition considers Type I and Type II adversary s...This paper defines the security notion for Certificateless Threshold Signatures （CLTHS）. Different from the adversarial model defined by Wang, et al. （2007）, our definition considers Type I and Type II adversary separately. At the same time, the authors develop the simulatability and relationship between certificateless threshold signature and the underlying certificateless signature. We also propose the first CLTHS scheme which is proved existentially unforgeable against adaptively chosen message attack without random oracles. Compared with the previous scheme by Wang, et al. （2007）, our scheme does not use hash function and is more efficient.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant Nos. 61033014,60970110,60972034the National 973 Program under Grant No.2007CB311201
文摘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This research is supported by the National Natural Science Foundation of China under Grant Nos. 60773086, 60970110, 60972034, and the National 973 Program under Grant No. 2007CB311201.
文摘This paper defines the security notion for Certificateless Threshold Signatures （CLTHS）. Different from the adversarial model defined by Wang, et al. （2007）, our definition considers Type I and Type II adversary separately. At the same time, the authors develop the simulatability and relationship between certificateless threshold signature and the underlying certificateless signature. We also propose the first CLTHS scheme which is proved existentially unforgeable against adaptively chosen message attack without random oracles. Compared with the previous scheme by Wang, et al. （2007）, our scheme does not use hash function and is more efficient.
