A cryptographic method that uses multiple substitution alphabets to encrypt plaintext. In [monoalphabetic rotation ciphers](Monoalphabetic%20rotation%20ciphers.md) each letter in the [plaintext](Plaintext.md) is always substituted with the same letter in [ciphertext](Ciphertext.md) In a polyalphabetic substitution cipher, substitution depends on the position of the letter and a key. This makes polyalphabetic substitution ciphers more secure. #Cybersecurity #TerminologyDefinitions #ConceptExplanation #Beginner