OpenDime (before the chip removal)

Opendime v3 Guide (2019)

In the first half of this guide, I walk through how to setup and use the Opendime. In the second half, I outline the steps required to ‘unseal’ the Opendime so that you can sweep or spend the funds.

Opendime review

If you want to read my review of the Opendime v3, check out this post.

Setting up the Opendime

This setup process shouldn’t take you longer than about 10 minutes.

  1. Plug your Opendime into a computer or laptop. The green light on the USB should stay on, while the red light should flash briefly. If this is NOT the case, return all the units.
  2. Open the USB on your desktop. There should be four files.

3. Open up the “index”. You should see this page.

  1. Find a picture (or other files) and copy them to the USB. Anything you move onto the USB isn’t saved. During the transfer, the USB will eject itself and your computer might show an error. Don’t worry about that.

  1. When it reconnects itself, the green light on the USB should be on, but briefly flicker.
  2. You should see these files now (they’ll all be read-only).

  1. Open the “index” file again. This will now show your Bitcoin (BTC) payment address (which you’ll send funds to) and links to check the balance of this Bitcoin (BTC) address and verify the device.

  1. For peace of mind, select ‘Verify’. If the device does NOT show this confirmation, then contact Opendime support.

  1. Send Bitcoin (BTC) to the payment address. Verify the balance by selecting ‘Check Balance’ in the “index” file, or copy the payment address into any third-party Bitcoin (BTC) blockchain explorer (e.g.,

Until you want to spend these funds, that’s all you need to do. Just make sure you keep the device safe, as you can’t access the bitcoin without it.

Unsealing the Opendime

When you’re ready to access the funds, you’ll need to ‘unseal’ the Opendime. This permanently changes the device in order to reveal the private key. Once you’ve done this and swept the funds (i.e., moved all funds in the Opendime into a secure wallet), the device should be disposed of.

Before unsealing your Opendime, make sure that you:

  • Have access to a secure machine.
    • I used a laptop which had just been reinstalled.
  • Understand how to sweep funds using your preferred wallet.
    • I used Electrum 3.0.5 (on Mac) for this guide. Search for keyword “sweep” in your wallet documentation if you’re not sure how to do it.

I swept the funds to a desktop wallet, but you can sweep to a mobile wallet too. If you are sweeping to a mobile wallet, disable the Internet connection on your desktop before connecting the Opendime to it.

  1. To reveal the private key, you need to poke out a chip on the Opendime. Something like a pin or paper clip will work fine. This video shows you how it’s done.

2. Once you’ve moved this little chip, the private key is no longer hidden.

3. Plug the Opendime into your computer. It should now alternate between flashing green and red. This confirms that the private key has now been revealed.

  1. Open up your Electrum wallet. Go to Wallet > Private Keys > Sweep.

  1. In the window that pops up, select the small folder icon in the bottom right. Select the file named ‘Private Key’ on your Opendime. You can leave the other settings alone in Electrum.

  1. Something like this should pop up. This just confirms that you’re sending theĀ funds from the Opendime to your own wallet.

  1. Once the transaction has confirmed, the Opendime is now trash. You’re safe to bin it.



Leave a Reply

Get interesting stuff like this
in your inbox

Thanks for subscribing!

Something went wrong. Try again or contact me.