SLIP-39 splits a secret into multiple mnemonic shares. A chosen number of shares (the threshold) recombines into the original seed; fewer than the threshold reveals nothing. This is different from simply writing a seed down several times: any single share is useless on its own.
SeedSigner can create SLIP-39 shares, import and extend them, load them from text, QR or a SeedKeeper, and store individual shares on a SeedKeeper.
SLIP-39 is disabled by default. Enable SLIP-39 seeds in Settings → Advanced. Enable Extendable SLIP-39 shares if you want shares that can be extended with additional groups later (also the default for Satochip/Specter compatibility).
Two entropy sources:
- Tools → SLIP39 seed (camera) — entropy from the camera.
- Tools → SLIP39 seed (dice) — entropy from dice rolls.
You choose the share configuration (how many groups, how many shares, and the threshold) and the word length (20 or 33 words), then the shares are generated and shown. Write each share down (or save it to a SeedKeeper). Keep enough to meet the threshold.
Seeds → Load a seed → SLIP-39 Shares, then enter shares from any of:
- Text – type each word.
- QR – scan a share QR.
- SeedKeeper – load a stored share.
SeedSigner collects shares until the threshold is met, then reconstructs the seed and shows its fingerprint.
When backing up a SLIP-39 seed, choose To SeedKeeper and select which share to
store. Each share is stored as its own labelled secret (SLIP39:<label>). Because a
single share is not enough to reconstruct the seed, distributing shares across multiple
cards is a reasonable multi-location scheme.
Once the shares are combined, the resulting seed is a normal in-memory seed and can be used anywhere a seed can — including Satochip Functions → Initialise with Seed → SLIP-39 Shares.