Playfair Cipher 1.not even the large number of keys in a monoalphabetic cipher provides security 2.one approach to improving security was to encrypt multiple letters 3.the Playfair Cipher is an example 4.invented by Charles Wheatstone in 1854

playfair cipher. the website for encrypt and decrypt the message

java实现的Playfair密码算法，可以实现加密和解密功能-java implementation of the Playfair cipher, encryption and decryption functions can be achieved