消息的发送者使用广播加密算法通过广播信道将消息发送给用户.公钥加密算法和追踪算法结合在一起,可构成一个公钥广播加密方案.提出了一个完全式公钥广播加密方案.在以往公钥广播加密方案中,消息发送中心替每个用户选择解密私钥,分配解密私钥.而在完全式公钥广播加密方案中,用户的解密私钥是由用户自己所选择的.用户可以随时加入或退出广播系统.当消息发送者发现非法用户时,不要求合法用户作任何改变,就能够很方便地取消这些非法用户.此外,证明了方案中加密算法在DDH假设和适应性选择密文攻击下是安全的. The sender of the message uses the broadcast encryption algorithm to send the message to the user through the broadcast channel.The public key encryption algorithm and the tracking algorithm combine to form a public key broadcast encryption scheme.A complete public key broadcast encryption scheme is proposed.In the past In the public key broadcast encryption scheme, the message sending center selects the decryption private key for each user and distributes the decryption private key, while in the full public key broadcast encryption scheme, the user’s private decryption key is selected by the user himself / herself. At any time to join or leave the broadcast system.When the sender of the message found an illegal user does not require any changes made by legitimate users, can easily cancel these illegal users.In addition, it is proved that the encryption algorithm in the program DDH assumptions and adaptive selection Text attack is safe.