Terminology

Cryptography

• Art or science of hidden writing

  • from Gr. kryptós, hidden + graph, r. of graphien, to write

• It was initially used to maintain the confidentiality of information.

• Steganography

  • from Gr. steganós, hidden + graph, r. of graphien, to write

Cryptanalysis

• Art of science of breaking cryptographic systems or encrypted information.

Cryptology

• Cryptography + cryptanalysis

Cipher

• Specific cryptographic technique.

Operation

• Encryption: plaintext (or cleartext) -> ciphertext (or cryptogram).

• Decryption: ciphertext -> plaintext

• Algorithm: way of transforming data.

• Key: algorithm parameter