Originally Posted by

**hunkydory19** In this cryptosystem we use the ordinary English alphabet A-Z with the letters numbered from 0 to 25. We number digraphs using the enumeration to base 26. We encode digraphs using the affine transformation f(x) = 213x + 111(mod 676).

How would you encode the message FINAL?

If anyone knows about this topic could they please explain step by step the process encoding messages?

Thanks in advance!

Code:

A 0
B 1
C 2
D 3
E 4
F 5
G 6
H 7
I 8
J 9
K 10
L 11
M 12
N 13
O 14
P 15
Q 16
R 17
S 18
T 19
U 20
V 21
W 22
X 23
Y 24
Z 25

Using X to pad FINAL to an even number of charaters:

FI=5*26+8

NA=13*26+0

LX=11*26+23

Now apply the transformation

RonL