Lock
Locking sends your bitcoin to an address that only your own key can open, on a date you choose. Until then nobody can move it, not even you. This kind of lock is called a timelock.
The test network is a practice copy of bitcoin. Its coins are free and worth nothing. Nothing here touches real money until the way home has been proved for the wallets people actually use, and this page says which those are.
This runs on a test version of bitcoin. Its coins are free, worthless and cannot be bought. Use it to find out how this works. Do not send real bitcoin to anything on this page.
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Nobody outside this project has checked the code that builds a lock. A mistake could leave coins stuck. If you are thinking of a large amount, wait for that review.
Who you are
You have to be on the register first: sign the declaration, which is free. A lock belongs to the key you signed with, so this page can work it out from your signature. You are not asked for any key, word or password here, and this page never holds any.
How long
Your bitcoin comes home on the date, whatever happens, and nobody can stop it.
If bitcoin's price halves, you cannot sell. Only lock what you can leave alone for the whole time. A longer lock counts for longer, and leaves you exposed for longer.
Say who you are and choose a length.
How you'll lock
Taking a lock home has been tested with a Ledger on this page and with the Crowdlock app. Sparrow, Electrum and other wallets can send to a lock, but nobody has yet shown they can sign to take it home. Use one only if you can do that yourself.
Locking is public. A lock that isn't published isn't counted.
A sat is the smallest unit of bitcoin. 100,000,000 sats make one bitcoin.
Pick one way.
With a Ledger, on this page
This browser cannot reach a Ledger. It needs Chrome, Edge or Brave on a computer. Phones, Firefox and Safari cannot do it. Use the app or any wallet below, or come back on a computer.
Chrome, Edge or Brave on a computer, with your Ledger plugged in, unlocked and the Bitcoin app open. Close Ledger Live first. The Ledger shows you the payment and you approve it on the device. This page never sees a key.
Change the fee
A vbyte is the unit a payment's size is measured in. A higher rate is confirmed sooner and costs more.
With the Crowdlock app
If you have the Crowdlock app, lock there. It is a bitcoin wallet that knows about locks, and it can take them home too. The app is in early test builds.
From any wallet
Send to this address from a wallet you control.
It is for this length, made today. The date is rounded to midnight (UTC), so on another day the same choice gives a different address. That is fine, it is simply another lock, but send everything for one lock to the one address you were shown. Add a little extra for the network fee your wallet will charge.
Check the address before you send
The address can be rebuilt by anybody from the facts below, and your wallet or the lock format in the documents can confirm it. If it does not rebuild, do not send.
Nothing here is secret, and you do not need to keep it: the register publishes the same facts. It is the recipe for the lock. You will never type these into anything yourself.
Check and publish
A lock address is just a string of characters. Nobody can tell it is yours, or that it counts, unless you say so. Publishing adds your lock to the register once the bitcoin has one confirmation. A confirmation means the network has written your payment into the blockchain.
Publishing puts your lock on the register, with your membership and the amount, for anyone to see. It can't be undone.
Not publishing doesn't make it private. Anyone can work out your lock address from your public key. It only means the fund doesn't count it, and this page can't show it to you when it's time to take it home.
If you don't want this to be public, don't lock.
After midnight UTC this page works out a different address for the same choices, and it can no longer publish this one. You can publish before or after you send: the register keeps looking until the bitcoin has arrived.
Has it arrived?
Once it is published and confirmed, it shows on the register.
Take a lock home with a Ledger
Once a lock's date has passed, you can bring its bitcoin back to your Ledger's address. Nobody else is involved. The Ledger shows you the payment and you approve it.
A lock that was never published will not appear in this list. The date is judged by the bitcoin network's own clock, which runs about an hour behind real time on real bitcoin.
This browser cannot reach a Ledger. It needs Chrome, Edge or Brave on a computer. Use the Crowdlock app, or come back on a computer.
Change the fee
If a message here mentions an xpub: that is a public key a Ledger needs to see before it will sign. It is not secret.
Taking it home
On the date, the key you signed the declaration with can move the bitcoin to any address you choose, with nobody else involved. Until then, nobody can.
What you will actually do: open a tool that knows about locks, tell it which lock, and approve one payment with your own wallet or device. You will not paste anything or work anything out.
What has been proved, and what has not. Sending to a lock works from any wallet. Taking the bitcoin out needs your wallet to sign for an unusual kind of address, and that is where wallets differ.
- The Crowdlock app's own wallet: proved on a test network.
- A Ledger: proved on a test network, in the Crowdlock app by cable and Bluetooth, and on this page. One real-bitcoin lock has been made with a Ledger in the app. Nobody has taken a real-bitcoin lock home yet, because none has reached its date.
- Sparrow, Electrum and others used directly: not tested. We do not know that they can sign for this kind of address, and will not say they can until it has been tried.
This is why the page is closed for real bitcoin: a lock that cannot be taken home is the one mistake that cannot be undone. Everything a tool needs is public, so any future tool can do it.
Before you lock real bitcoin
Read the risks page first. It is short, specific and not reassuring. Bitcoin you lock is out of reach until its date, except through a purchase you have personally signed for.
In many countries sending, receiving or moving bitcoin has tax or reporting rules. They differ, and finding out yours is up to you.