Split a secret (Shamir)

Splits a secret (for example a master password) into n shares. Only k shares together restore it; fewer reveal nothing. Distribute the shares to different people or places.

Secret

Number of shares (n)

Shares required (k)

Shares (one per line)

Restored secret

Important: with too few or wrong shares, restoration may yield a wrong result. Verify the result before destroying the original. Each share carries a checksum against typos, but no information about the secret.

Method: Shamir secret sharing over GF(256) using the “shamir-secret-sharing” library (externally audited). Everything runs locally.