In PKI System, CA provide certificates to management the public key, while the private key is protected by other sides such as the KEA(Key Escrow Agent) or managed by self. In fact, The smart card is widely used.

• 在现有的PKI体系中，由PKI下的证书机构(Certificate Authority，CA)提供证书来维护公钥，采用智能卡作为私钥管理解决方案。