monoalphabeticsubstitution
nounUK /ˌmɒnəʊælfəˈbɛtɪk ˌsʌbstɪˈtjuːʃən/
US /ˌmɑːnoʊælfəˈbɛtɪk ˌsʌbstɪˈtuːʃən/
A secret code where each letter is always swapped for the same other letter.
The puzzle used monoalphabeticsubstitution, so every A became an X throughout the message.
SYNONYMS
RELATED WORDS
OTHER MEANINGS
2. A way of hiding a message by replacing each letter with one fixed partner letter.
Kids made a monoalphabeticsubstitution to pass notes in class.
3. A code-breaking topic where the same letter swap rule applies to the whole text.
The spy story featured a monoalphabeticsubstitution that was easy to crack.
4. A basic encryption method that uses only one scrambled alphabet.
The old diary was written with monoalphabeticsubstitution to keep it private.