polyalphabetic code

noun

UK /ˌpɒliˌælfəˈbɛtɪk kəʊd/

US /ˌpɑːliˌælfəˈbɛtɪk koʊd/

A polyalphabetic code is a secret code that uses more than one set of letter swaps to hide a message.

The spy used a polyalphabetic code so that each letter of the message was scrambled in a different way.

SYNONYMS

polyalphabetic cipher multi-alphabet cipher Vigenère cipher complex substitution cipher

RELATED WORDS

encryption cipher cryptography substitution cipher decryption

OTHER MEANINGS

2. A cipher in which the substitution alphabet changes at different points in the message.

Breaking a polyalphabetic code is harder than breaking a simple substitution code.

3. Any coding system that switches between multiple alphabets to make patterns harder to spot.

The puzzle used a polyalphabetic code to confuse anyone looking for repeated letters.

4. A method of encryption where the same plaintext letter can turn into different ciphertext letters.

In a polyalphabetic code, the letter 'e' might become 'Q' in one spot and 'M' in another.