No it requires a threshold of 12 out of 18 keys to be acquired by an attacker. Jurisdictional resilience is the standard technique for preventing this kind of attack--e.g. having operators in the USA, Russia, Japan, Israel, Europe, South America, India, Singapore, etc.

Smart contracts operate completely transparently. There is no private data other than the private keys used to sign transactions. Unless you just encrypt the data, then you need a key to access it, and the nodes don’t have that key.

I know a guy that worked on this same problem leveraging TEEs (trusted execution environments). This enables 3rd parties to run the software and join the network and take part without having access to the data. Unless they find a flaw in the TEE that can be exploited.

I'm only vaguely familiar with the concept of smart contracts, but from what I understand I can't see how it'd fair any better at enabling cryptographic timelocks - the core problem is designing encryption which can't be broken before a set period has passed. The naive approach is requiring to make a scheme which assumes it'll take X amount of time to brute force with Y resources.

That's obviously flawed because you can't constrain an enemies resources, and if the period is long there's plenty of room for improvement of algorithms/hardware which will shorten the time to brute force the scheme.

This only works because we create a scheme which can't reasonably be brute forced by classical means, and a human organization enforces/controls the time period.

In order to create something like that proposed in the posted link with smart contracts, the self contained smart contracts would have to employ a cryptographic timelock themselves. Otherwise, the smart contracts will be dependent on external (human) input, so it's just reinventing the same thing.

Ergh, could you explain how did you come to this conclusion?

> wonder if a smart contract could be useful in this scenario

It could not, at least with the capabilities of EVM or other mainstream smart-contract platform (I don't even thing it would be possible in theory but I may be wrong on this)

Do the trustees have to be known or can they remain fully anonymous ?

In that case, the whole warrant theory isn't the last word.