It’s difficult—the main technical thing is probably identifying (important) non fakes, rather than identifying fakes, which seems very difficult (though maybe another useful layer). The main two mechanisms I think are reputation-based (the point being to make it costly or impossible to fake a reputation for honesty) and cryptographic-based (the point being you can prove A didn’t produce X by proving that H produced X).
It’s difficult—the main technical thing is probably identifying (important) non fakes, rather than identifying fakes, which seems very difficult (though maybe another useful layer). The main two mechanisms I think are reputation-based (the point being to make it costly or impossible to fake a reputation for honesty) and cryptographic-based (the point being you can prove A didn’t produce X by proving that H produced X).