letter-by-letter encryption
1NSA encryption systems — The National Security Agency took over responsibility for all U.S. Government encryption systems when it was formed in 1952. The technical details of most NSA approved systems are still classified, but much more about its early systems has become …
2Deniable encryption — In cryptography and steganography, deniable encryption is encryption that allows its users to convincingly deny that the data is encrypted, or that they are able to decrypt it[citation needed]. Such convincing denials may or may not be genuine.… …
3AACS encryption key controversy — A controversy surrounding the AACS cryptographic key arose in April 2007 when the Motion Picture Association of America and the Advanced Access Content System Licensing Administrator, LLC (AACS LA) began issuing demand letters[1] to websites… …
4cryptology — cryptologist, n. cryptologic /krip tl oj ik/, cryptological, adj. /krip tol euh jee/, n. 1. cryptography. 2. the science and study of cryptanalysis and cryptography. [1635 45; < NL cryptologia. See CRYPTO , LOGY] * * * Introduction …
5Cryptography — Secret code redirects here. For the Aya Kamiki album, see Secret Code. Symmetric key cryptography, where the same key is used both for encryption and decryption …
6Enigma machine — Military Enigma machine …
7Substitution cipher — In cryptography, a substitution cipher is a method of encryption by which units of plaintext are replaced with ciphertext according to a regular system; the units may be single letters (the most common), pairs of letters, triplets of letters,… …
8One-time pad — Excerpt from a one time pad In cryptography, the one time pad (OTP) is a type of encryption, which has been proven to be impossible to crack if used correctly. Each bit or character from the plaintext is encrypted by a modular addition with a bit …
9ROT13 — replaces each letter by its partner 13 characters further along the alphabet. For example, HELLO becomes URYYB (or, rev …
10Caesar cipher — The action of a Caesar cipher is to replace each plaintext letter with one fixed number of places down the alphabet. This example is with a shift of three, so that a B in the p …
