The security issue of keys in conventional cryptosystem mainly concerns with secrecy and anti-crackdown of the key material, while in public key system this issue mainly means the correctly banding between the public key and the owners identity.

• 传统的对称密钥系统的密钥安全主要指密钥的保密性和不被破解； 公钥密码系统的密钥安全主要是指公开密钥和身份绑定的正确性。