Let’s look at an old Roman age encryption scheme. Let’s say we intercepted a message from a
known Celtic hacker group. We know from experience that this group uses the characters from A to Z, then
a space, and then the numerals from 0 to 9 and employs a wrap around (moving left from A gives us 9).
The first leading pairs of letters tell us what the substitution code is using the code phrase “Trudy Jones”.
For example if the first two pairs are uy du the code is 24 and 32. This would mean that we move the first 2