A portion of a VigenËre cipher square is given below using five (1, 2, 14, 16, 22) of the possible 26
alphabets. Using the key word bow, which of the following is the encryption of the word advance
using the VigenËre cipher?
Exhibit:

A.
b r r b b y f

B.
b r r b b y h

C.
b r r b c y f

D.
b r r b j y f

Explanation:
The VigenËre cipher is a polyalphabetic substitution cipher. The key word bow indicates which
alphabets to use. The letter b indicates the alphabet of row 1, the letter o indicates the alphabet of
row 14, and the letter w indicates the alphabet of row 22. To encrypt, arrange the key word,
repetitively over the plaintext as shown in Table. Exhibit:

Thus, the letter a of the plaintext is transformed into b of alphabet in row 1, the letter d is
transformed into r of row 14, the letter v is transformed into r of row 22 and so on.