The Vigèner Cipher - Encryption/Decryption
Try Beaufort
L - The length of the available alphabet. For english alphabet using a-z it
will be 26, since it is 26 letters in the alphabet.
m∈M - Your selected plaintext is a message(m) which is an element of
the entire message space(M)
k∈K - Your selected keyword is a key(k) which is an element of the
entire key space(k)
c∈C - The resulting ciphertext(c) which is an element of the entire
ciphertext space
m
n - The n-th letter of the current plaintext
message. The current plaintext letter being encrypted.
k
n - The n-th letter of the current keyword, this
a modulo operated value which is relative to the keyword length.
c
n - The n-th letter of the current ciphertext. The
letter of the ciphertext that is being deciphered.