Topic: Time locked transactions (Read 353 times)

You mean unlock it before the timelock has expired?
I'm afraid that's not possible, unless you've accidentally made a mistake while creating the timelock.

This is what Achow mentioned on my other thread:


Source: https://bitcointalksearch.org/topic/m.24712001

Can anyone tell me how to unlock the transection in between?

Lol, I've written that article myself and I even used the Bitcointalk thread I've posted as a source for that article (it's mentioned at the bottom)
I'd suggest just following Tryninja's instructions (in the thread I posted), if you know what you're doing. It's much faster that way.

What about reading the previous replies?
The answer to your question already has been posted:




For a set-by-step guide with picture, you can visit https://steemit.com/bitcoin/@daan/how-to-create-time-locked-transactions-with-bitcoin-free-bitcoins-inside.

Concerning for the information about a time-locked address, you can verify the time until the funds have been locked, the address whose permission is required to withdraw the funds and the address where the funds are located, using Coinb.in.

I've also asked a similar question before on this forum and got a really amazing reply.
Easy step-by-step instructions to create a time-locked transaction.

https://bitcointalksearch.org/topic/m.24710770

I know you're probably looking for a more in-depth technical answer, but just sharing this in case anyone else is interested in creating a time-locked transaction.

Yes. Effectively... nLockTime is a bit like a "Dead Man's Switch".

You setup a transaction, that is not valid until X time (X = block number). Any time before X, you can invalidate that transaction simply by spending one of the inputs in a different transaction. If no action is taken, then the original transaction can be broadcast as a valid transaction after X has occurred.

GreenAddress uses nLockTime as a fail-safe for it's MultiSig wallets... They create a (partially) signed transaction (with their key) that sends all your funds to a nominated address from your 2-of-2 wallet with an nLockTime calculated to be around 90 days in the future. This way, if GreenAddress service goes down, you can simply sign the transaction with your key (so it is fully signed), and then broadcast it to recover your funds in 90 days.


I don't think there is anything specifically documented that it cannot be broadcast... I think it's more just that because the transaction is considered "invalid" due to the lockTime that nodes will treat it like any other "invalid" transaction (bad signature, "missing" inputs, zero fee etc) and reject it (and thus refuse to broadcast/relay it).


All you can do is store it somewhere... most nodes won't accept invalid transactions, so attempting to broadcast it likely won't work. Why would a node want to store an "invalid" transaction in it's mempool? There is no point.

It isn't "unsafe" to have it stored somewhere (email, cloud storage, harddrive, given to recipient etc.) because, as already mentioned, if you change your mind you can simply invalidate it by spending one of the inputs in a transaction prior to nLockTime, and no-one can alter the "signed" transaction.

Ok let me make my question more specific:
Suppose I create a transaction with OP_CHECKLOCKTIMEVERIFY set into some block in the future. I understand that this transaction is invalid until we reach that block.
My question was after I create and sign this transaction, what do I do with it? Of course it cannot be mined since it is invalid. Heisenberg_Hunter said I can only store it in a safe place, maybe sending it to the recipient letting him know that I have this transaction ready to broadcast it as soon as I can. But is it somewhere documented that it cannot be broadcasted by bitcoin nodes?

Time Locking is a feature which when enabled restricts you to spend the btc present in the wallet for a certain time period or until the network reaches a specific block height. Time Locking features are used frequently for investment purposes or locking of funds for the heirs.

At the time of this writing, the block height is 525160. Create a transaction and enter the nlocktime say 650000.
Unless the blockheight entered hasn't been exceeded, your transaction is invalid, won't get confirmed and would never be broadcasted in the network.

Yes transaction is invalid and would remain off-chain until the specified blockheight is reached. If you broadcast the transaction before the blockheight, it will not get included in the blocks. You can even cancel the transactions before the locktime is reached.

No. Mempool consists of unconfirmed transactions. Mempool consists of set of transactions that are broadcasted in the network but are not included in the blocks by a miner. Locktime transactions are not broadcasted to the network before the blockheight is reached. So you need to store the transactions in a safe place and need to broadcast it to the network at the right time when the locktime reaches.


More about Locktime here
Someone correct me if I am wrong   

I assume you are referring to nLocktime. It is simply a parameter in every Bitcoin transaction that can be set to zero.
Yes, the nLocktime value means that the transaction can not be added to a block that has a lower block number than the one specified in the nLocktime filed.

https://en.bitcoin.it/wiki/Protocol_specification#tx

I'm looking for information on time-locked transactions for bitcoin. How is this transaction created exactly? Does this transaction remain off-chain between the sender and the receiver until the time has elapsed? Does this transaction remain on the mempool until that time?