This is a really interesting approach for managing secret state. Another life ago I implemented a rule-based version of everyone's favorite collectible card gam

This is a really interesting approach for managing secret state. Another life ago I implemented a rule-based version of everyone's favorite collectible card game, and it was P2P (so each client ran the full rules engine and synchronized the initial random seed and the each player's actions). I could never figure out a good way of limiting cheating by peaking at either your own deck or the opponents. I looked into commutative encryption and mental poker, but at that point my interest in the project fizzled and I stopped working on it. This approach would work for keeping randomness in the game, and homomorphic encryption could be used to hide the contents of the opponent's deck.