古典密码算法中的单表代换密码算法、移位密码算法、Vigenere密码算法。算法比较简单，用命令的方式。可以随机生成明文和密钥。-Classical cryptographic algorithm in a single table substitution cipher, transposition cipher, Vigenere cipher. Algorithm is relatively simple, way to use the command. Can be randomly generated and the key explicitly.