Improvement of Feng-Yuan nonrepudiable threshold proxy signature scheme
Feng-Yuan不可否认门限代理签名方案的改进

Feng-Yuan pointed out that Hsu et al.'s threshold proxy signature scheme lacks of undeniability,and proposed an improvement scheme with nonrepudiation.A conspiracy attack on Feng-Yuan's improvement scheme shows that their scheme suffered from forgeability,unidentifiability and deniability.Furthermore,an improved scheme was presented to remedy the security weakness of Feng-Yuan's scheme.