/shamir — Shamir's Secret Sharing
Split a secret — a password, private key, or seed phrase — into N shares so that
any K of them reconstruct it exactly, but any K-1 reveal nothing at all, not even a partial hint.
Store each share somewhere different: a different person, device, or safe. Whoever collects K shares
holds the whole secret, and if more than N-K shares are lost the secret is gone for good. Everything
runs in this tab with
crypto.getRandomValues — nothing is sent to the server.Below the threshold, shares are not weak encryption — they are information-theoretically blank. Combining fewer than K shares (or one that was tampered with) does not leak a fragment of the secret; it produces uniformly random-looking bytes. This tool refuses to attempt a join below the threshold, and flags a mismatched tamper-check as a failed reconstruction rather than showing wrong bytes as if they were real.