COMPUTER FUNDAMENTALS

Detailed explanation-1: -A polyalphabetic cipher substitution, using multiple substitution alphabets. The Vigenère cipher is probably the best-known example of a polyalphabetic cipher, though it is a simplified special case. The Enigma machine is more complex but is still fundamentally a polyalphabetic substitution cipher.

Detailed explanation-2: -A poly-alphabetic cipher is any cipher based on substitution, using several substitution alphabets. In polyalphabetic substitution ciphers, the plaintext letters are enciphered differently based upon their installation in the text.

Detailed explanation-3: -Polyalphabetic Cipher is a substitution cipher in which the cipher alphabet for the plain alphabet may be different at different places during the encryption process. The next two examples, playfair and Vigenere Cipher are polyalphabetic ciphers.

Detailed explanation-4: -A monoalphabetic cipher uses fixed substitution over the entire message, whereas a polyalphabetic cipher uses a number of substitutions at different positions in the message, where a unit from the plaintext is mapped to one of several possibilities in the ciphertext and vice versa.

Detailed explanation-5: -noun. : polyalphabetic substitution in which the choice of alphabets is limited (as by a key word) compare progressive-alphabet cipher.