Help and answers

QuorumPony uses Shamir Secret Sharing. You choose a total number of cards and how many it takes to recover. The secret is split so that any group of that size rebuilds it, while any smaller group reveals nothing about it. A common choice is 3 of 5: five cards, any three recover.

As long as you still hold at least the number of cards needed to recover, the secret is safe. With a 3 of 5 split you can lose up to two cards and still recover. If you fall below the threshold, the secret cannot be rebuilt, so plan your split with that margin in mind.

No. That is the point of the design. Any number of cards below your recovery threshold reveals nothing about the secret. One card on its own is mathematically useless to anyone who finds it.

Open Recover, then add cards one at a time by scanning each card's QR code with the camera or typing its printed code. Once you have added enough, QuorumPony rebuilds the original and shows it to you. You can copy it or save it to a file.

It confirms that a stored card is still intact and tells you which backup it belongs to, without rebuilding the secret. It is useful for checking on cards in long term storage. Note that a valid set of cards is confirmed as present and intact, but a successful recovery is only guaranteed by actually recovering.

Yes, entirely. Everything happens on your device. There is no account, no sync, and no server. The app does not transmit your secret and keeps no copy of it. You can put the phone in airplane mode and it works exactly the same.

On paper, by you. QuorumPony produces cards for you to print and store. The app itself does not save your secret or your cards after you leave the screen. You decide where the cards live.

Yes. The cryptographic core is open source on GitHub under the Apache 2.0 license, so anyone can read, build, and check the exact code that protects your keys. It is constant-time Shamir Secret Sharing over GF(2^8) with no external dependencies.

Yes. There are no ads, no in-app purchases, and no subscription.