Coins unspendable until a particular date?

[btcusury]

Say I promise 1 BTC in address X be sent to a recipient at date Y. The recipient is not yet known, but will be one of array(Z). Is there any way to create a cryptographic proof of the promise? In other words, a way to guarantee that the 1 BTC is not spent before date Y and is not sent to any address other than one in array(Z).

[BowieMan]

I don't know if that is part of the Bitcoin core protocol (which it has to be in order to work consistently with all bitcoin nodes and miners). But it is definitely possible to postpone a transaction until a specified date or block, if I remember correctly. Could you lay out a case where your method would be more useful than the existing methods?

[bigasic]

I dont think that is possible with the bitcoin core. It would be available for a bitcoin wallet, like multibit. it would be fairly easily to implement, but instead of it sending the coin out, maybe just do a reminder so that you can do it manually, just in case something has changed.

[keithers]

This is kind of a cool idea though...kind of similar to a post dated check...

[btcusury]

The cryptographic proof of the promise doesn't have to be part of the Bitcoin protocol. Could there be a way, perhaps, to use Ethereum (or anything else) to do this, simply converting whatever currency to BTC at the exchange rate at date Y?

Thanks for your input y'all.

[FUR11]

The cryptographic proof of the promise doesn't have to be part of the Bitcoin protocol. Could there be a way, perhaps, to use Ethereum (or anything else) to do this, simply converting whatever currency to BTC at the exchange rate at date Y?

Thanks for your input y'all.

Yeah, but it would be a good thing to be part of the core protocol. All the altcoins and features of more or less centralized systems don't really help Bitcoin itself.

[Meuh6879]

Is there any way to create a cryptographic proof of the promise?

not in the blockchain function.
you can use a "scheduled" transfer from a virtual wallet ... but you always can cancel it, so no ... you can't schedule bitcoin transfer.

[inBitweTrust]

Say I promise 1 BTC in address X be sent to a recipient at date Y. The recipient is not yet known, but will be one of array(Z). Is there any way to create a cryptographic proof of the promise? In other words, a way to guarantee that the 1 BTC is not spent before date Y and is not sent to any address other than one in array(Z).

Using and Oracle with multisig escrow would allow this.

[Xch4ng3]

a way to guarantee that the 1 BTC is not spent before date Y

From your own wallet? I doubt it.

I'm sure if you create some kind of escrow through a web portal you could technically set up Bitcoin on a server and have it schedule transfers.

[FUR11]

a way to guarantee that the 1 BTC is not spent before date Y

From your own wallet? I doubt it.

I'm sure if you create some kind of escrow through a web portal you could technically set up Bitcoin on a server and have it schedule transfers.

But that is something we definitely don't want. This is an example for something where definitely no escrow or external service is needed for it to work! This is simply something that may be incorporated into the bitcoin protocol. All the information are there and can be associated with the transaction.

[hhanh00]

I believe you can even though I haven't tried.

Transaction inputs have a 'lock time' before which it cannot be accepted into a block.
Transaction outputs are essentially a script. The most common is the pay-to-hash that allows someone to claim the coins if he provides a matching public key and digital signature. However, one can specify more complicated scripts. Armory implements what you want as a multi-sig lockbox but it doesn't have the time delay feature yet.

Regards,
--h

[Razick]

I think there is a "time-lock" variable in a standard transaction. I don't know if that's what it does, but it might be worth looking in to.

[btcusury]

Say I promise 1 BTC in address X be sent to a recipient at date Y. The recipient is not yet known, but will be one of array(Z). Is there any way to create a cryptographic proof of the promise? In other words, a way to guarantee that the 1 BTC is not spent before date Y and is not sent to any address other than one in array(Z).

Using and Oracle with multisig escrow would allow this.

Could you elaborate on this? What is an Oracle? How could multisig escrow be used to this end?

[kolinko]

Could you elaborate on this? What is an Oracle? How could multisig escrow be used to this end?

Here's a brief khan-academy style video explaination:
https://www.youtube.com/watch?v=boPW1FwNu4c

It's a part of this tutorial:
https://github.com/orisi/wiki/wiki/Mastering-Distributed-Oracles

In short: you create a multisig address that locks the money in, and will be unlocked using one or more impartial arbiters/oracles.

The current Orisi examples assume that oracles are the only ones who sign the tx, but you could add sender/receiver's signatures to the mix to be sure that oracles won't run away with money. (it's described within the whitepaper: https://github.com/orisi/wiki/wiki/Orisi-White-Paper )