You can create a timelock smart contract requiring a future state of the blockchain to have been reached. Once that time has been reached, you can freely execute the function on the contract to retrieve the information. Tested it years ago, to lock up 1 ETH in essentially a CD for a year.
The trust is held in your own code implementation of the contract and that ETH will continue to exist and not be hard-forked or Shor'd or something.
That's not how it works: You can fundamentally not store secrets in smart contracts, you do need off-chain agents for that. (How would a smart contract prevent me from reading anything published on a blockchain?)
> Tested it years ago, to lock up 1 ETH in essentially a CD for a year.
That's not locking up a secret, that's locking up value.
But it seems like there might be a game theoretic way to ensure that, as your sibling commenter has outlined.
The trust is held in your own code implementation of the contract and that ETH will continue to exist and not be hard-forked or Shor'd or something.