Vigenere cipher, type of substitution cipher invented by the 16th-century French cryptographer Blaise de Vigenère.
(1) Data encryption in which the original plaintext structure is somewhat concealed in the ciphertext by using several different monoalphabetic substitution ciphers.
(2) Key : Specifies particular substitution (e.g 'a' is 1 ---> shift one = 'b')
