关键词: 门限签名, 合谋攻击, 伪造性, 内部攻击

Abstract: An improved threshold signature scheme is proposed to overcome the weakness of Cai et al’s scheme. The security of this scheme is analyzed. The results show that the improved scheme can not only resist conspiracy attacks and forgery attacks essentially, but also protect the personal broadcasted information with applying message recovery equation. In addition, it can realize the computing ability of group’s public key by constructing a secure distributed key generation protocol. As a result, the improved scheme is securer than the former schemes.

Key words: threshold signature, conspiracy attack, forgery ability, inside attack