You can prove ownership of any Bitcoin address generated by your BitBox02 by signing an arbitrary message through the Electrum wallet - no private keys ever leave your hardware device. Before you begin, make sure you’ve paired Electrum with your BitBox02 via our detailed blog post “Use the BitBox02 with Electrum wallet” to establish a secure connection between the apps.

Prerequisites

• Electrum wallet installed (download only from https://electrum.org and verify signatures) 
• BitBoxApp running and your BitBox02 unlocked and connected via USB
• Electrum configured to use the BitBox02 as described in the blog post above

How to sign messages via Electrum with your BitBox02

Follow these steps to securely sign any message with an address from your BitBox02:

1. Click the Addresses tab in Electrum’s main window
   
2. Find the address you want to prove ownership of within the displayed list of addresses and right‑click it to open the context menu.
   
3. Select Sign/verify message from the menu.
   
4. Copy and paste the message you need to sign [1] and click the 'Sign' button thereafter [2].
   
5. Check the message and address on your BitBox02’s screen, then confirm the signature on-device as seen in the following video: BitBox02 sign message with Electrum.
6. Copy the generated signature from Electrum and use it wherever proof of ownership is required.

Troubleshooting tips

• If you don’t see the Addresses tab, enable it via View > Show addresses in Electrum’s menu.
• Should signing fail, close the BitBoxApp, unplug and replug your BitBox02, then retry the process.