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

MonoAlphabetic Substitution Cipher written in C

Implementation of Monoalphabetic Cipher in C

In cryptography, a Caesar cipher, also known as Caesar s cipher, the shift cipher, Caesar s code or Caesar shift, is one of the simplest and most widely known