A、Repetitive encryption obscures any repeated patterns that may have been present in the plaintext.反复加密以掩盖任何可能在明文出现的重复模式

B、The previous DES output is used as input.之前的DES加密输出被用来作为输入

C、Individual characters are encoded by combining output from earlier encryption routines with plaintext.单个字符从之前明文加密程序的结合输出来进行编码

D、A given block of plaintext and a given key will always produce the same ciphertext.一个给定的明文和一个给定的密钥将总是产生相同的密文。