This does not have to be truly unique. But, it should be pretty hard to duplicate. The idea is easily identify a replay and a paired screenshot. If their ID values differ, then they do not pair.
Some of the work done to determine offline, online, and replay allows putting this ID on the board title in replays and displaying at the end of games (after the Damage Test is killed) for players who finish the game.
This does not have to be truly unique. But, it should be pretty hard to duplicate. The idea is easily identify a replay and a paired screenshot. If their ID values differ, then they do not pair.
Some of the work done to determine offline, online, and replay allows putting this ID on the board title in replays and displaying at the end of games (after the Damage Test is killed) for players who finish the game.