What will it be seeded with? I suggest using something that would be practically impossible for anybody to guess any better than at maximum entropy before submitting their program, but could easily serve as a nothing-up-my-sleeve number after the tournament, e.g. the hash of (say) the first Bitcoin block generated after the submission deadline.
Another possibility would be the hash of results of a few public lotteries, football matches, weather data etc. on the evening of 5 July, taken from previously agreed sources and written in a previously agreed format.
You can use a random number generator.
What will it be seeded with? I suggest using something that would be practically impossible for anybody to guess any better than at maximum entropy before submitting their program, but could easily serve as a nothing-up-my-sleeve number after the tournament, e.g. the hash of (say) the first Bitcoin block generated after the submission deadline.
This seems good in theory, but how much fiddly hacking would be required in practice to identify and extract this Bitcoin block for hashing?
Another possibility would be the hash of results of a few public lotteries, football matches, weather data etc. on the evening of 5 July, taken from previously agreed sources and written in a previously agreed format.