very gut.
./mash [input file] [difficulty]1.1 Reads 64 bytes of the file.
1.2 Splits it into 2 32-byte chunk.
1.3 Adds them to Mashtree with key=0.
1.4 Checks the whole tree for chunks with same keys, removes them from the tree, mashes them with each other, adds the mashed chunk to the tree with key + 1.
2. Repeat step `1` until no chunk with identical keys remain.
2.1 Then, mashes chunk 0 with all the other remaining chunks, no key testing.
3. Then the program mashes the chunk 0 with random characters, and then with itself.
4. If difficulty was given, it checks the mashed chunk with the difficulty, otherwise continues mashing.
Maybe using it as proof of work? :)))