monoalphabetic cipher

noun

UK /ˌmɒnəʊˌælfəˈbɛtɪk ˈsaɪfə/

US /ˌmɑːnoʊˌælfəˈbɛtɪk ˈsaɪfər/

A secret code where each letter is always swapped for the same other letter.

The spy used a monoalphabetic cipher to hide the message.

SYNONYMS

simple substitution cipher single-alphabet cipher substitution cipher monoalphabetic substitution

RELATED WORDS

cryptography cipher encryption plaintext ciphertext

OTHER MEANINGS

2. A cipher in which the cipher alphabet is a fixed rearrangement of the plain alphabet.

In a monoalphabetic cipher, the mapping never changes during encryption.

3. A basic encryption method often used in puzzles and classroom cryptography lessons.

Students cracked the monoalphabetic cipher by guessing common letters.

4. A code vulnerable to frequency analysis because letter patterns are preserved.

The monoalphabetic cipher was broken quickly using letter frequencies.