Show HN: Timelock.dev – Send a secret into the future using timelock encryption

One could build a service just around the fact that the fastest theorical time it takes to transmit information around earth is around 130ms. This means that the absolute maximum number of layers that could be used in a day is well below 1 million. Scale that over a few billion layers or more, and reveal a new key every roundtrip, and you would've got yourself a much simpler timelock encryption.

The problem that arise is (and which is solved by the spacecraft to Neptune) is that with any earth based system, someone could secretly move copies of both ends closer together, secretly, and decrypt the lock faster than expected. Putting a spacecraft on a trajectory with no realistic chance of ever coming back makes this possibility impossible (as long as the layers of keys are encrypted only when the spacecraft arrived at its destination. Even if the delay between earth and neptune vary wildly, it is predictable, and any local system could piggyback a larger scale system like this for safety

Slip a key into a random unsolved case file in LA / must digitize all files to find it

Choose a key from the DNA of a living Nobel prize winner

Place an opaque nondescript sticker over the lens of a surveillance camera in London / must disassemble all cameras to find it

Writing Sherlock Holmes level material is not hard

Not with ethereum or a smart contract, because any ethereum node can simulate any execution of a smart contract.

But it occurred to me that you can sort of do something like this with a proof of work-like algorithm, though the time to solve would still be variable.

Essentially you'd need a network of "miners" and instead of a block, you'd have a node encrypt a message with an encryption key of a set difficulty (decryption key length), based on the target decryption time and the network hash rate (hash rate probably is not the correct term, but I'll use it for conciseness).

The miners would then work to decrypt the data using the knowledge of the key length.

I'm not sure how you would incentivize the miners to work on decrypting it though, and the node which encrypted it would of course have knowledge of the message, so I don't see how this could be used in practice.

In theory if your miners were running something like a tamper-proof secure enclave (I'm not even sure if these truly exist) perhaps there's a way to attest their own hashrate, and then an encrypted message can be proposed by a node to a subset of miners which collectively have the assumed hashrate. The secret-encrypted data can then be re-encrypted for each miner, with their public key.

This ensures other miners not participating in the challenge can't attempt to decrypt the data.

The problem here is incentivization over a long period of attempting to decrypt the data. You'd have to offer a reward large enough to incentivize the miners to cooperatively work to decrypt the message for the longest possible amount of time it could take to decrypt the message.

edit: I think for this to work you'd first need to encrypt the data for each miner which should participate in the challenge, and then encrypt it with the secret key. That way a miner which solves this can publish the decryption key and the still-encrypted payload, which only they can decrypt, and all the other miners can apply the same solution to verify the published solution and solved message with their own private keys.

edit 2: I suspect there's something potentially useful here, but I don't know enough about secure enclaves to really know if it's feasible to implement in a way that prevents gaming, so if someone knows more about such things, feel free to take the idea and run with it.

Yes, Jimmy Hoffa is a "famous" disappeared person case here in America.

There are only a few "famous mysteries" that became such widespread memes in American culture. The ones I can think of are:

1. What happened to Jimmy Hoffa (who killed him?). "The Irishman" on Netflix is a Scorsese adaptation of a "nonfiction" book that documents an old Mafia hitman claiming to have killed Hoffa. (The book is nonfiction, the guy's claims are somewhat contested.)

2. What happened to Amelia Earhart? (Early female aviator who disappeared attempting to fly around the world).

3. What happened to and who was DB Cooper? (A man hijacked an airplane, traded some hostages for a duffle bag of cash at an airport when such a thing was possible, told the pilots to fly to Canada and then jumped out of the plane with a parachute and the duffle bag somewhere over the pacific northwest).

4. Who shot JFK?

This is a really cool idea using fundamental properties of physics but I don't think it works.

If the spacecraft is trusted by the person with the secret, it's much simpler to instruct the spacecraft to only disclose the secret after a set date. You don't seem to gain anything from the carded complexity.

If the spacecraft isn't trusted, there's nothing it stopping it disclosing all the key pairs at once.

I think the best bet at the moment is something like Rivest-Shamir-Wagner time lock puzzles, which requires a fixed number of sequential computations to perform.