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Multisig Setup

Checklist

Keystone 3 Pro multisig with Sparrow

Last reviewed: October 2026

TL;DR

The Keystone 3 Pro can be one of the three keys in a Sparrow 2-of-3, entirely by QR code, once it runs the Bitcoin-only firmware. You import its key into Sparrow, then import the finished multisig back into the Keystone so it can check receive addresses itself. I haven’t used a Keystone in this setup myself: the steps follow Keystone’s and Sparrow’s own documentation, checked October 2026.

Where the Keystone fits

The Keystone 3 Pro never connects to your computer for transactions. Everything goes through QR codes: its camera reads Sparrow’s screen, and your webcam reads the Keystone’s. It can replace one of the guide’s three devices, as long as you keep three different makers.

Like the BitBox02, it stores your multisig after you confirm it. Keystone’s guide says it writes the setup to its secure chip and shows every cosigner before you accept. So it counts as a device that checks addresses against your real wallet, not just against what the computer tells it. The company started in China as Cobo Vault and makes the devices there; with three brands, no single maker can reach your coins anyway.

The Bitcoin-only firmware comes first

Keystone’s multisig guides are written for the Bitcoin-only firmware. Keystone says the first Bitcoin-only version that could join a multisig was 1.1.0; at the time of writing the current one is 3.1.0-BTC (September 17, 2026). The device ships with the multi-coin firmware, so you switch once, before you create the seed.

Treat the switch as one-way

Keystone’s guide describes the change to Bitcoin-only as irreversible. Its firmware page says firmware types can be upgraded across each other. I couldn’t confirm which is right, so assume you can’t go back.

What you need

  • A Keystone 3 Pro that passed the tamper check, plus Keystone’s own Device Verification (scan a QR code on Keystone’s website, type the code it shows).
  • A microSD card formatted as FAT32 and a card reader, for the firmware update.
  • Sparrow installed and verified on your signing computer (step 3), with a webcam.
  • Your notes from step 4 with a letter for each device.

Steps

1. Install the Bitcoin-only firmware

  1. Type keyst.one/firmware into the address bar yourself. Under Keystone 3 Pro, choose the Bitcoin-only firmware and the microSD option. Keystone says your device needs at least firmware 1.0.4 to do this.
  2. Check the file’s SHA256 checksum against the value on that page, as you would for any download.
  3. Copy the file, named exactly keystone3.bin, to the root of the card. Put the card in the Keystone and go to Device Settings → System Settings → About → Firmware Update → Via MicroSD Card. Keep the battery above 20%.

2. Create the seed

Create a new wallet on the Keystone and write the words on paper, later on metal (step 5). Never photograph them or type them anywhere. The Keystone also offers Shamir backups; choose the normal word list instead, so any brand can restore it (BIP39 vs SLIP39).

3. Add it to the wallet in Sparrow

  1. On the Keystone, open Wallet Profile (top left of the home screen), choose Show/Export xPub and select Multisig Wallet. A QR code appears.
  2. In Sparrow, in one of the keystore tabs of step 6, click Airgapped Hardware Wallet, find Keystone Multisig and click Scan. Hold the Keystone in front of the webcam.
  3. Check that the derivation path reads m/48’/0’/0’/2′ and write down the master fingerprint.
  4. Add the other two devices, then click Apply.

4. Import the multisig into the Keystone

Keystone’s guide is clear that this step is needed before the Keystone can sign for the multisig.

  1. In Sparrow, open the wallet’s Settings tab, click Export at the bottom, choose Keystone Multisig and Show QR.
  2. On the Keystone: Wallet Profile → Add MultiSig Wallet → Via Camera, and scan Sparrow’s screen.
  3. The Keystone shows the wallet and its cosigners. Compare every fingerprint with your notes. Only then tap Confirm and enter the Keystone’s password.

5. Check an address

On the Keystone, go to Wallet Profile → Multisig Wallet → Set as Current Wallet, then Receive. Compare the address, every character, with the one Sparrow shows in its Receive tab. Keystone itself recommends this check. Then do the same on your other registered device, as in step 8. A mismatch means stop: see receive address doesn’t match the device screen.

6. Sign

In Sparrow, create the transaction, click Finalize Transaction for Signing and then Show QR. Scan it with the scan icon on the Keystone’s home screen, check what it shows, tap Sign and confirm. The Keystone shows the signed transaction as a QR code; click Scan QR in Sparrow to read it back. Start with a small amount (step 9).

Common mistakes

  • Trying to set up the multisig on the multi-coin firmware.
  • Exporting the single-sig xPub instead of Multisig Wallet.
  • Skipping step 4. The Keystone then has no record of your multisig.
  • Confirming the import without comparing the fingerprints.
  • Scanning QR codes that didn’t come from your own Sparrow. Keystone warns against this too.

What it costs

Keystone’s own shop lists the Keystone 3 Pro at $149 (October 2026). Prices change, so check the shop.

Buy from Keystone · Buy on Amazon

Buy only from the maker’s own shop or from Amazon.com itself (“Ships from and sold by Amazon.com”), never from a reseller: here’s why. Whichever you pick, do the tamper check when it arrives.

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