Cryptography, simply defined, is the art of combining some input data, called the plaintext, with a user-specified password to generate an encrypted output, called ciphertext, in such a way that, given the ciphertext, it is extremely difficult to recover the original plaintext without the encryption password in a reasonable amount of time. The algorithms that combine the keys and plaintext are called ciphers. Various ciphers are documented on this page for easy use.....(free).....