He now shifts each plaintext alphabet by the number written below it to create ciphertext as shown below − .He will arrange plaintext and numeric key as follows − The sender wants to encrypt the message, say 'cryptography'.Numeric representation of this key is '2 8 15 7 4 17' The sender and the receiver decide on a key.Each alphabet of the key is converted to its respective numeric value: In this case,Ĭ → 2, i → 8, p → 15, h → 7, e → 4, r → 17. This scheme of cipher uses a text string (say, a word) as a key, which is then used for doing a number of shifts on the plaintext.įor example, let’s assume the key is 'cipher'. Giovan Battista Bellaso however, the scheme was later misattributed to Blaise de Vigenère in the 19th century, and is now widely known as the Vigenère cipher. The method was originally described by Giovan Battista Bellaso in his 1553 book La cifra del. The Vigenère cipher has been reinvented many times. It is a simple form of polyalphabetic substitution. In cryptography, a Vigenère cipher is a method of encrypting alphabetic text by using a series of different Caesar ciphers based on the letters of a keyword.
