3.4 Affine-Chiffre
The Affine Cipher is a special case of the Substitution Cipher.
The encoding function is restricted to functions of the form
e(x) = ax + b mod 26
For the decryption to be possible the affine function
ax + b mod 26 = y must be injective.
This is the case with a=1,3,5,7,9,11,15,17,19,21,23,25.
The parameter b
can be any element in Z26.
For a = 1 we have Shift Cipher.
source
The applet only shifts characters and leaves all other symbols unchanged.
