[jtjhoxhw] Burrows wheeler substitution cipher

An "amateur" cipher based on the bzip2 algorithm.

Apply a simple substitution cipher to the plaintext (key, part 1).

Perform Burrows-Wheeler transform.

Initialize the "Move To Front" table to a random permutation of the alphabet (key, part 2), and perform Move to Front.

(Is skipping RLE ok?)

Apply arithmetic coding.  The probabilities are public, but the order of letters within the range (0...1) is key, part 3.  Perhaps use a order-1 arithmetic coding instead of order 0 (the next table depends on the previous character).

Express the real number in base N, with the order of the N symbols as key, part 4.