改进的方案具有不可否认性，以及抵抗原签名人的伪造攻击和公钥替换攻击等优点。

Improved scheme has advantages of nonrepudiation, against he original signer's forgery attack and public key substitution attack etc.

youdao

改进后的方案具有不可否认性，不使用安全信道，以及抵抗公钥替换攻击和合谋攻击等优点。

Improved schemes have advantages of nonrepudiation, using insecure channel, against the public key substitution attack and collusion attack etc.

youdao