[pbaehr]

This is interesting in its own right, but the Assange use case doesn't really make sense to me. Wikileaks doesn't want the encryption to be broken after a certain amount of time, they want it broken based on the condition of assassination.

[arielweisberg]

The primitive for this is a dead man's switch. I wonder what the cryptographic equivalent would be.

Some sort of computational network that will always make progress towards decrypting the data unless the soon to be dead man injects something using his private key that sets the network back preventing completion?

The network can't identify that the soon to be dead man is preventing progress?

Sounds like a fun research project. Maybe tie it to some coin mining network.

[betterunix]

The problem with using a secure protocol is that you need to trust the parties to not just instantiate a second version of the protocol without you. If you can trust them to do that, you can just give them shares of the secret and trust them not to recombine the shares unless you die.

[gwern]

I'd argue that Wikileaks doesn't want it released solely on his death but more like 'Assange's assassination or 10 years, whichever comes first', so it does get released eventually.

And I'm surprised no one sees a use-case in recent events: if I were DPR, I'd be happy if usable time-lock crypto existed so I could, say, lock a wallet of 100k btc for 10 years, and give it to a friend as a backup; I don't have to worry about the friend deciding that they'd like to retire to Patagonia, but if I'm 'shot resisting arrest', at least I left my friend a fortune. Or, even if he hands a time-locked wallet over to the FBI, he's delayed them spending it for 10 years and given the Bitcoin economy that much more time to grow and be able to absorb a sudden infusion of 1% of the money supply.

As it is, he's basically in an all-or-nothing position.

[tlrobinson]

I believe your DPR use-case is possible with Bitcoin, using "lock time" contracts. https://en.bitcoin.it/wiki/Contracts

Every transaction can have a lock time associated with it. This allows the transaction to be pending and replaceable until an agreed-upon future time, specified either as a block index or as a timestamp (the same field is used for both, but values less than 500 million are interpreted as a block index). If a transaction's lock time has been reached, we say it is final.