1: plaintext - original message
2: ciphertext - coded message
3: cipher - algorithm for transforming plaintext to ciphertext
4: key - info used in cipher known only to sender/receiver
5: encipher (encrypt) - converting plaintext to ciphertext
6: decipher (decrypt) - recovering plaintext from ciphertext
7: cryptography - study of encryption principles/methods
8: cryptanalysis (code breaking) - study of principles/ methods
of deciphering ciphertext without knowing key
9: cryptology - field of both cryptography and cryptanalysis