Bitcoin identity
Signing proves that your impact board is genuinely yours -- not an impersonation. You sign a short message with a Bitcoin address you control. The signature is publicly visible on your board and verifiable by anyone, including AI assistants.
The message you sign
cleanproof.io/u/[your-user-id]
Find your exact message on your Profile page under Bitcoin identity. Copy it precisely -- spacing matters.
Which address should I use?
Any Bitcoin address you control. It does not have to be the address you funded your pools from -- the identity claim is separate from the per-receipt verification. Use whichever address is most convenient to sign with.
Option A -- Hardware wallet via Sparrow
Recommended for Ledger, Trezor, Coldcard, Bitbox, Passport
Download and install Sparrow Wallet from sparrowwallet.com. It is free and open source.
Open Sparrow. Go to File -> New Wallet. Give it a name.
Choose your hardware wallet type and connect via USB, or import your xpub manually under Keystore. Sparrow never needs your seed phrase -- it only reads your public key to generate addresses.
Click Apply. Sparrow will scan your addresses. Go to the Addresses tab.
Find any address you want to sign with. Right-click it and choose Sign Message.
Paste your impact board message exactly as shown on your Profile page.
Click Sign. Your hardware wallet will prompt you to confirm. Approve on the device.
Sparrow shows the signature. Copy it, along with the address. Paste both into your Profile page under Bitcoin identity.
Your private key never leaves your hardware device. Sparrow only communicates the message to sign.
Option B -- BlueWallet on mobile
Simplest option if you have a hot wallet
Open BlueWallet on your phone. Tap the Bitcoin wallet you want to sign with.
Tap the three dots (...) in the top right corner.
Tap Sign/Verify Message.
In the Message field, paste your impact board message exactly as shown on your Profile page.
Tap Sign. BlueWallet will sign instantly using the wallet's private key.
You will see an Address field and a Signature field appear. Copy both values.
Go to your CleanProof Profile page, scroll to Bitcoin identity, and paste both values. Tap Save.
Any Bitcoin wallet with a Sign Message feature works the same way -- BlueWallet is just the most common.
How anyone can verify your signature
Once saved, your address, message, and signature are visible on your public impact board. Anyone can verify them at bitcoinmessageverifier.com -- paste the three values and the tool confirms whether the signature is valid for that address and message.
AI assistants can also verify Bitcoin message signatures directly. A funder can show their impact board to a colleague and say "ask your AI to verify the signature" -- it will confirm the board belongs to a real Bitcoin holder without requiring any technical knowledge from the viewer.