Paper-survivable backups
Printable recovery cards for Bitcoin and digital inheritance.
Printed share cards that survive device failures, password loss, and hosted-service shutdowns. Each card carries one threshold share — a single card cannot open the vault, the required number combined can.
- Paper-survivable
- QR + human-readable
- Free recovery
Designed for recovery plans that need to outlast devices and online services
Devices fail and online services disappear. Printed cards, stored in separate locations with a verified offline recovery package, give your family a recovery path that does not depend on the hosted website.
What gets printed on each card
Why physical recovery cards still matter
Works with an offline recovery package
The recovery flow is intended to be runnable from an offline package containing the recovery code, a checksum, and the documented vault format — independent of the hosted website.
QR code with a human-readable transcription
Each share is encoded twice: a QR code for a phone scan and a grouped base32 string for the human eye. A worn card with a scratched QR still recovers from the text; a faded text line still recovers from the QR.
One card cannot open the vault
A valid set of fewer than K cards does not reveal the protected secret. The cards may still contain operational metadata needed for recovery, but not the secret contents.
Designed for separate physical storage
Each card is a single page sized to fit a fireproof folder, a safe-deposit envelope, or a sleeve in a will binder. Store cards in separate locations so a single event cannot destroy the quorum.
Why people choose DMSKey
- Client-side cryptography
- No account required for recovery
- Open recovery process
- Printable paper artifacts
- Threshold recovery (K-of-N)
- One-time payment
- Recovery survives a lost or destroyed card when you choose N greater than K
Free and paid plans use the same recovery format
Paying changes plan limits and printable extras — not the encryption or recovery process. Free vaults produce share cards with a faint diagonal watermark on every page; DMS Full removes the watermark and adds the printable executor letter. The QR encoding, base32 layout, CRC-32 guard, and embedded vault package are identical at every tier.
- Any K-of-N up to 255 shares
- No watermark
- Printable executor letter PDF
- Free recovery, forever
Questions about the printed cards
What information is printed on each recovery card?
Each card carries one Shamir share encoded as a QR plus a grouped base32 transcription, a CRC-32 error-detection checksum, the vault identifier and threshold (K and N), and the full encrypted vault package. The Shamir share alone reveals nothing; the encrypted vault package cannot be decrypted without K shares.
Why is the encrypted vault copied onto every card?
It makes recovery self-contained — any K cards combined are enough, with no separate vault file to find. The encrypted package reveals nothing without the required K shares, so duplicating it across cards does not weaken the secret.
How do paper recovery cards survive when a device or service fails?
The cards do not depend on any specific device or cloud account. They are paper artifacts: store them in a fireproof folder, a safe-deposit box, or a will binder. The recovery flow is designed to run from an offline package, so the cards remain usable even if the hosted website is gone.
What page size and print quality should I use?
Each card is one page sized to fit A4 or US Letter. Print in black-and-white at 600 dpi or higher so the QR scans reliably from a phone camera at a relaxed distance.
Laser, inkjet, lamination — what should I use?
Use a laser printer when possible: laser toner is more archival than inkjet and tolerates light moisture. Inkjet works but use pigment ink rather than dye ink. Avoid thermal paper entirely — the print fades within months. Lamination protects against moisture and handling but check that it does not glare under a phone camera. Archival paper (acid-free, 80 gsm or heavier) and a fireproof folder for long-term storage are recommended. For sensitive vaults, use a trusted local printer that does not retain jobs or upload documents to a vendor cloud.
What if a custodian smudges or tears their card?
Each card carries both a QR and a grouped base32 text — either one alone is enough to recover that share. A torn QR can be re-typed from the visible base32; a smudged base32 can be re-scanned from the QR. You can also reprint a fresh card from the JSON file in the original .zip without redoing the vault.
What does the CRC-32 checksum protect against?
CRC-32 detects accidental scan or transcription errors and rejects shares that fail the check before reconstruction. It is not a cryptographic integrity check and is not a defence against deliberate tampering. Vault integrity is authenticated separately by AES-GCM.
Make the artifact your family will actually find
The cards are the recovery artifact that has to survive. Set the vault up, print the cards, hand them out, and run a dry-run. Store the official offline recovery package and its checksum with the estate plan.