This is an excellent write-up on the different on-chain randomization approaches. If both secret messages are somehow discovered by a hacker, I wonder if it would still be possible to influence the outcome by controlling enough of the hash rate. You would have to be able to insert funds at exact indexes within the participation phase, control the number of participants, and have complete influence over the final future blockhash. Thoughts?
Good point! If you managed to capture all this information, it would theoretically be possible. However, being able to get this much control is essentially impossible. We emphasize "pseudorandom" because nothing is ever truly 100% random.