One can forge an effective proxy signature that will be accepted by the signature verifier and that will not identify the true signer to management. 该攻击能够伪造出有效的代理签名，使签名验证人可以接受该代理签名，但管理中心并不能通过此签名来辨认出代理签名人的身份。
The signature verifier must have access to the public key certificate that contains the public key associated with the private key used to produce the signature. 签名验证者必须有权使用包含与用于生成签名的私钥关联的公钥的公钥证书。
