Cryptography

In the art of cryptology, we have two different sciences: cryptography and cryptanalysis. Cryptography secures information based on mathematical algorithms, while cryptanalysis deals with exposing ciphertexts created by cryptography systems. These two sciences  coexist side by side. More simply, cryptography deals with hiding information, and cryptanalysis breaks cryptosystems to reveal the hidden information. Cryptography is not a new science, it is old. There are some classical cryptography techniques, such as Sumerian cuneiform, Egyptian hieroglyphics, scytale, Vigenère cipher, the Caesar cipher, and the ROT13 cipher.

Cryptosystems

The implementation of cryptographic techniques is called a cryptosystem; sometimes it's called a cipher system. The following diagram describes a simple cryptosystem. The sender encrypts the plaintext with an encryption algorithm, which is a mathematical process using an encryption key. The output of that operation generates a ciphertext that will...