How would that work? Everything in the blockchain is public. You can't automatically have something be revealed in the blockchain; if that worked, what stops so

How would that work? Everything in the blockchain is public. You can't automatically have something be revealed in the blockchain; if that worked, what stops someone from simulating blocks being added to the blockchain and seeing what your contract does? Unless the decryption was somehow linked to the set of the proof-of-works involved, but I don't think anyone yet has an idea of how that could be done. You could later publish a decryption key into the blockchain that the contract uses, but I don't think that's "automatic" in the sense the earlier posts were hoping for.