Vigenere Cipher

The Vigenere Cipher is composed of a series of Caesar ciphers based on a Key Phrase. The first letter of the plaintext message is shifted using the first letter the key phrase, the second letter of the plain text is shifted based on the second letter of the key phrase, and so on. If the plaintext message is longer than the key phrase, the key phrase is repeated.

In the default example below, shows how the plaintext message YOU ARE MY SUNSHINEis encrypted into the ciphertext EIG BFK GK TITMTJBK using the key GUMBO

Plaintext:
YOU ARE MY SUNSHINE
Key:
GUMBO
Ciphertext:
EIG BFK GK TITMTJBK

Breakdown

Plaintext:
Y
O
U
A
R
E
M
Y
S
U
N
S
H
I
N
E
Key:
G
U
M
B
O
G
U
M
B
O
G
U
M
B
O
G
CipherText:
(plaintext + key) % 26
E
I
G
B
F
K
G
K
T
I
T
M
T
J
B
K