Definition[]
A cipher is an algorithm for encryption or decryption. A cipher converts plaintext into ciphertext.
Military[]
A cipher is
“ | [a]ny cryptographic system in which arbitrary symbols (or groups of symbols) represent units of plain text of regular length, usually single letters; units of plain text are rearranged; or both, in accordance with certain predetermined rules.[1] | ” |
References[]
- ↑ U.S. Department of Defense, Joint Pub. 1–02: DOD Dictionary of Military and Associated Terms (Nov. 8, 2010, as amended through May 15, 2011) (full-text).