Use cases / Digital assets
Seed phrases are bearer instruments — lose them and the assets they control are unrecoverable.
The problem
Paper fades, burns and floods. A seed phrase written on paper is one house fire away from permanent loss — and anyone who finds it can drain your wallet.
Steel plates survive fire but not theft. If someone finds your plate, your funds are gone. And if you hide it too well, your family may never find it.
Signing devices protect your keys while you are alive but do nothing for the people who need access after you are gone.
Sharing your seed phrase with a single person — a friend, a lawyer or a spouse — creates a new single point of failure. That person can be compromised, coerced or simply lose access.
The solution
Encrypt your seed phrase in an encrypted QR code backup called a block — mitigate signing device loss, theft and coercion with additional secrets, offsite storage and watch-only wallets.
Learn more →Split your seed phrase and seed extensions into a set of blocks called a blockset — distribute blocks among designated heirs, vaults and institutional custodians, establishing inheritance governance that survives the unthinkable.
Learn more →Boot Superbacked OS on dedicated hardware. Create block containing seed phrase. Keep block alongside signing device in case signing device fails. Passphrase can live in your password manager — seed remains air-gapped.
Generate seed extensions (BIP39 passphrases) in app and store them in separate block as additional secrets — each protected by different passphrase. Under coercion, reveal first secret’s passphrase while others remain undetectable.
Store seed extension block in safe deposit box or other institutional vault with duress safeguards. Signing transactions then requires both signing device and physical access to seed extension — mitigating $5 wrench attacks.
Store master public keys in separate block kept alongside signing device — like seed extension block, but for creating watch-only wallets and receiving addresses at home, without a trip to the safe deposit box.
For a second factor, enable YubiKey protection — without it, passphrase alone cannot unlock block.
To restore, boot Superbacked OS on dedicated hardware, scan seed phrase block, enter passphrase (and plug in provisioned YubiKey if YubiKey protection is enabled) and view seed phrase. Seed extension and master public key blocks follow the same process.
Boot Superbacked OS on dedicated hardware. Create blockset containing seed phrase and seed extensions — choose threshold (2-of-3, 3-of-5 or 4-of-7). All blocks share same passphrase — seed remains air-gapped.
Give block 1 and passphrase to designated heirs — sharing a single block among heirs means no heir can act alone. Store block 2 in safe deposit box or other institutional vault with duress safeguards. Give block 3 to institutional custodian without revealing passphrase.
For larger holdings, use 3-of-5 or 4-of-7 blockset. Distribute additional blocks to institutional custodians in different jurisdictions.
Superbacked OS includes trezorctl for managing Trezor signing devices. BIP39 seed phrases are auto-detected during recovery and displayed as numbered word lists — with root fingerprint of each seed phrase and seed extension pair, so heirs can confirm signing device derives the same wallet. Child seed phrases can be derived by index (BIP85) from a restored seed phrase.
When the time comes, heirs boot Superbacked OS on dedicated hardware, gather required number of blocks, enter passphrase and view seed phrase and seed extensions allowing heirs to provision signing device.
No solution protects against everything — being honest about that is part of earning your trust.
Superbacked enforces strong passphrases but cannot prevent reuse. If passphrase is reused from a breached service, brute-force protection is bypassed unless block or archive is also protected with YubiKey. Use built-in passphrase generator.
If you lose passphrase, block, archive or derived secret becomes permanently unrecoverable. Store passphrase in your password manager or another secure location.
If block, archive or derived secret is protected with YubiKey and YubiKey is lost, secret becomes permanently unrecoverable — passphrase alone is not enough. Back up challenge-response secret or provision a second YubiKey.
If someone gains access to both block and passphrase — for example, through unlocked password manager — secret is compromised. Lock devices when away.
If malware is running on computer when you create a block, archive or derived secret, secret could be captured before encryption. For high-stakes secrets, use Superbacked OS.
If too many blocks are lost — for example, losing 2 blocks in a 2-of-3 blockset — secret becomes permanently unrecoverable. Ensure custodians store blocks safely.
If enough custodians collude to meet threshold, they can recover seed phrase. Unlike credentials, crypto transactions are irreversible — choose custodians carefully.
For high-stakes secrets, use Superbacked OS — a hardened operating system that runs offline and persists nothing to disk.
Explore other use cases: critical credentials, signing keys and personal backups.
Copyright (c) Superbacked, Inc.