> ... there was no way that they could do the serial computation fast enough to know what actual beacon value they were creating.
But that also means they can't validate the calculation until long after it's used. For a video game I like this strategy (accept then verify) as you don't have to catch cheaters in the moment. For a system of currency, not so much.
Zcash was using it for a purpose where waiting a week or two to validate the random beacon was fine - it was a one-time calculation required by the mathematics of their trusted setup.
But yes, you are absolutely correct that for many applications that isn't feasible.
But that also means they can't validate the calculation until long after it's used. For a video game I like this strategy (accept then verify) as you don't have to catch cheaters in the moment. For a system of currency, not so much.