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!