Make the keys.
Prove you can recover them.

Do not improvise in the middle of seed creation. Obtain and test the hardware first. Print blank worksheets before any secret exists, or draw the grids by hand.

1. Download Ubuntu LTS from Canonical on a connected computer. Download its SHA256SUMS and signature files from the same official release directory.
2. Verify before writing the installer. Follow Canonical’s current signature and checksum procedure. A matching checksum proves the ISO arrived unchanged. Signature verification helps establish who published that checksum.
3. Write the verified ISO to a USB installer using a trusted imaging tool. Boot the future offline computer from it and erase the internal drive.
4. Install Ubuntu with full-disk encryption. Use a long, unique disk passphrase and a generic local account name. Do not store Bitcoin secrets in the account profile.
5. Update once, then sever networking. Complete needed operating-system updates before the machine becomes permanent offline infrastructure. Power down, remove or physically disable Wi-Fi and Bluetooth hardware, disconnect Ethernet, then boot again and confirm no network interface can connect.
6. Label its role. This machine verifies packages and writes removable media. It never stores the seed, and it never goes back online without being rebuilt from scratch afterward.

gpg --verify SHA256SUMS.gpg SHA256SUMS
sha256sum --check SHA256SUMS

1. Confirm the board says Raspberry Pi Zero v1.3, not Zero W or Zero 2 W. Version 1.3 has no Wi-Fi or Bluetooth hardware.
2. If the board does not have GPIO headers, solder the 40-pin header before installing the screen. If you are not comfortable soldering, buy the version with headers already installed.
3. Connect the camera ribbon with the contacts oriented correctly. Seat the Waveshare LCD HAT evenly on all 40 pins.
4. Fit the parts into the case without pinching the camera ribbon. Do not power the Pi until the verified image is on the microSD card.

These commands match SeedSigner release 0.8.7, current when this page was reviewed. Before using them, check the official release page. If the version changed, use the filenames and verification instructions published with that release.

1. On the online computer, download the Pi Zero image, plaintext SHA-256 manifest, manifest signature, and seedsigner_pubkey.gpg from the official SeedSigner project.
2. Transfer those four files to the offline Linux computer. Import the project key locally, then independently compare its fingerprint with the fingerprint published through official SeedSigner sources.
3. From the directory containing the files, verify the signed manifest, then verify the image against it:

gpg --import seedsigner_pubkey.gpg
gpg --verify seedsigner.0.8.7.sha256.txt.sig
sha256sum --ignore-missing --check seedsigner.0.8.7.sha256.txt

The final command must report the Pi Zero image as OK. “Good signature” is not enough by itself. Compare the signing fingerprint through another official channel. Stop on a bad signature, fingerprint mismatch, or failed hash.

4. Use Raspberry Pi Imager or Balena Etcher on the offline Linux computer to write the verified pi0.img file to the microSD card. Let the imaging tool complete its read-back verification.
5. Insert the card, power the SeedSigner, and wait for the logo. Test the screen, joystick/buttons, and camera before generating anything valuable.
6. Once SeedSigner has loaded, the microSD may be removed. The seed will exist in RAM only and disappears when power is removed.

The 100-roll SHA-256 process I previously used was for a Nostr key. SeedSigner’s Bitcoin workflow is different. For a 24-word BIP-39 seed, SeedSigner’s documented process uses 99 rolls of a six-sided die.

1. Work alone in a private room with no cameras, phones, voice assistants, or windows overlooking the work surface.
2. On SeedSigner choose Seeds → Create a seed → Dice rolls → 24 words. Follow the current on-screen menu if labels have changed.
3. Roll honestly. Enter every result from 1 through 6 exactly as it lands. Do not discard inconvenient rolls and do not “improve” the randomness.
4. With ten distinguishable dice, your familiar rhythm still works: roll ten at a time and enter them in a fixed left-to-right order. After nine batches you have 90 rolls. Enter only the first nine dice from batch ten to reach 99. Mark the tenth position as unused before rolling so there is no ambiguity.
5. Confirm SeedSigner shows 99 valid rolls and generates a 24-word seed. Write the words by hand, in numbered order, twice checking spelling against the BIP-39 list shown by the device.

1. Use SeedSigner’s Verify Backup flow to re-enter or confirm the 24 words before trusting the copy.
2. Create a SeedQR by hand using SeedSigner’s guided transcription flow: Backup Seed → Export as SeedQR. For a standard 24-word SeedQR, use the official 29 × 29 template.
3. Use Confirm SeedQR on SeedSigner to scan and verify the hand-drawn QR. SeedSigner should be the only camera that ever sees it.
4. Make a durable metal copy of the 24 words for fire and water resistance. Verify every position again. Do not invent abbreviations unless the backup system explicitly documents them.
5. Store the copies in separate secure places. Anyone who finds either the words or SeedQR can spend the bitcoin. Do not store the seed beside instructions identifying the amount or wallet.

SeedQR is the seed. It is not a convenient public wallet QR. Never scan it with Sparrow, a phone camera, a normal webcam, or a generic QR application.

1. On the online computer, download Sparrow, its signed manifest, and the installer from sparrowwallet.com. Verify the manifest signature and the installer hash before installation.
2. Current Linux verification commands for Sparrow 2.5.5 are:

curl https://keybase.io/craigraw/pgp_keys.asc | gpg --import
gpg --verify sparrow-2.5.5-manifest.txt.asc sparrow-2.5.5-manifest.txt
sha256sum --check sparrow-2.5.5-manifest.txt --ignore-missing

Confirm the signing fingerprint through Sparrow’s official download page. The installer must report OK. Use the current version’s filenames when the project updates.

3. In Sparrow select File → New Wallet. Give it a non-sensitive name. Choose Single Signature and Native Segwit (P2WPKH).
4. Select Airgapped Hardware Wallet → SeedSigner → Scan.
5. On SeedSigner, load the seed from your hand-entered words or SeedQR. Use Seeds → select seed → Export Xpub → Single Sig → Native Segwit → Sparrow. Displaying the xpub as QR is safe for spending authority, but it is privacy-sensitive because it reveals the wallet’s addresses and history.
6. Scan the xpub QR into Sparrow. Compare the master fingerprint and derivation path shown on both devices. Apply the wallet settings and protect the Sparrow wallet file with a strong, unique password.
7. Back up Sparrow’s wallet file and exported public descriptor as privacy-sensitive recovery aids. They cannot spend without the seed, but they reveal wallet structure and activity.

1. In Sparrow open Receive and create a fresh address. Label it with its purpose or source before using it.
2. Do not trust the computer screen alone. Export or display the wallet descriptor/address QR from Sparrow, load the seed in SeedSigner, and use SeedSigner’s address verification flow.
3. Compare the complete address on SeedSigner with Sparrow and with the withdrawal screen of the exchange or sender. Check the first, middle, and final characters, not only the ends.
4. Send a small test amount. Wait for confirmation, then confirm Sparrow shows the expected transaction and balance.
5. Use a new receive address for each later payment. Address reuse unnecessarily links activity.

1. In Sparrow select Send. Paste or scan the destination, then verify it independently. Enter the amount, label, and fee rate.
2. Review the selected inputs, recipient output, change output, and fee. Click Create Transaction, then Finalize Transaction for Signing.
3. Choose Show QR. Sparrow displays an animated QR containing the unsigned partially signed Bitcoin transaction, or PSBT.
4. On SeedSigner select Scan QR. Scan the animated PSBT. Review the recipient, amount, change, and network fee on the SeedSigner screen itself.
5. If anything differs, reject it. If it is correct, approve and sign. SeedSigner displays a new animated QR containing the signed transaction.
6. In Sparrow close the original QR window, choose Scan QR, and scan the signed result from SeedSigner. Confirm the expected signature appears.
7. Broadcast from Sparrow. Power off SeedSigner to clear the seed from memory.

1. After the small test receive, record the wallet master fingerprint and one verified receive address. These are not secret, but keep them private.
2. Power off SeedSigner. This deliberately wipes the loaded seed from RAM.
3. Reload the seed using the hand-written words. Confirm the same master fingerprint and address appear.
4. Power off again. Reload using the SeedQR and repeat the comparison.
5. Complete the small test spend using the restored seed. A readable backup is not enough. Recovery has succeeded only when the restored signer can reproduce the wallet and authorize the expected transaction.
6. Only after both recovery methods pass should you destroy the temporary dice-roll log and consider moving more funds.

Single-signature with no passphrase is the deliberate starting point here. Passphrases and multisig can reduce some risks while creating new ways to lose access. Add complexity only after this procedure is routine and the recovery consequences are understood.