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QuorumPony splits a secret into backup cards using Shamir Secret Sharing: any few rebuild it, one card alone reveals nothing. Fully offline, open source, free on iPhone.

QuorumPony is a free, open-source iPhone app that backs up your most important secrets with real Shamir Secret Sharing. Split a wallet seed phrase, a private key, or a recovery code into a set of cards, choosing how many to make and how many it takes to recover. Any few rebuild the secret; any single card on its own reveals nothing. Everything happens on the device, with no account, no server, and no tracking.

QuorumPony is a free, open-source iPhone app for backing up the secrets you cannot afford to lose, built by NorseHorse, a solo independent developer. It uses real Shamir Secret Sharing: your secret becomes the constant term of a random polynomial over the finite field GF(2^8), and each card is one point on it. You choose a total and a threshold, for example five cards where any three recover the secret, and below that threshold the cards are information-theoretically empty, revealing nothing at all about the secret. Cards carry a QR code and a printed code, can be exported to a clean PDF for printing, and can be checked for integrity without rebuilding the secret. Everything happens on the device: QuorumPony is fully offline, with no account, no sync, no server, and no analytics, and the secret is never transmitted or stored. The cryptographic core is open source under Apache-2.0, a constant-time implementation with no external dependencies. QuorumPony ships in six languages and is part of a small family of privacy tools that also includes PGPony, AgePony, and RelayPony.