The app splits one BIP39 seed into two, three or four parts, each of which is an ordinary seed in its own right. Any part can be written down as words or transcribed as a SeedQR. Load the parts back in any order and you get the original. You can also XOR seeds you already hold to derive a new wallet from all of them.
It is N of N, which is how XOR works. Every part is required, no threshold and no spare. A missing part does not throw an error. It quietly produces a different valid seed that opens a real but empty wallet, so the app states the requirement three times before it generates anything, and refuses a duplicate part outright.
Quick release update: Seed XOR v0.1.2 is now available for Passport Prime on KeyOS 1.4 or later.
This is a QnA-signed third-party app, not Foundation-signed. The GitHub release includes the app ZIP, publisher certificate and SHA-256 checksums. The app showcase has updated device screenshots.
The app includes guided Standard and Compact SeedQR transcription for each part, plus a scan-back check. A complete hand-transcription and physical scan-back have not yet been tested end to end, so please start with a test seed if trying that flow.
As mentioned above, Seed XOR is N-of-N, not a threshold backup. Every part is needed; an incomplete set can produce a different valid wallet without an error. Optional BIP39 passphrases are separate. The app cannot access Passport’s master seed or Seed Vault, and it has not been independently security-audited. Keep another tested backup.