While there are many technologies which meet some of these requirements, only one provides the tools for meeting all of them: public key technology, implemented in the form of a Public Key Infrastructure (PKI).

• 有许多技术能够满足其中一些需求，而利用公开密码技术构建的公开密钥基础设施(PKI)提供的工具能够满足全部这些需求。