Repudiation of Cheating and Non-repudiation of Zhang's Proxy Signature Schemes

摘要

The paper discusses the correctness of Lee, hwang and Wang's comments on Zhang's porxy signtature schemes. In paprticular, it is shown that the cheating attack proposed by Lee, hwang and Wang can be detected by the owner of the signature scheme. It is argued that considering the ocntext in which proxy signatures are used, the attack is not a security problem. The work is concluded by a discussion about the non-repudiation controversy invorrectly observed by Lee, Hwang and Wang.