The public key cryptosystem secure against chosen ciphertext attacks is a very strong secure cryptosystem and is a useful primitive for designing protocols that resisting active adversary .
抗选择密文攻击公钥密码体制是安全性很高的密码体制,它是设计抗主动攻击的协议非常有用的工具。
If the data to be protected is already encrypted , then authenticity requires that a cryptanalyst would not be able to substitute a false ciphertext without detection .
待保护的数据已被译成密码,则可靠性要求密码分析员不能代之以伪造的密码电文而不被发。
In the context of message security , plaintext is used to differentiate from ciphertext to indicate that the text is not encrypted .