Ok, to clear a few things up with my previous post (to avoid confusion)
I gave the -Encoding Matrix- which you must take the inverse of
to decifer the coded message. Sorry for the mixup.
Second, after decoding with the inverse of the matrix given (its a
2x2) use 1=A, 2=B and so on, and 0=a space .
There, that should help 🙂

The Rahl

Penned by my hand on the 5th of Ero, in the year 233 AF.