🧩 Secret Sharing
Split a secret into shares and recover it (Shamir).
How it works
Each byte of the secret becomes the constant term of a random polynomial of degree K − 1 over GF(2⁸); each share is that polynomial evaluated at a different nonzero x. Any K shares recover the secret by Lagrange interpolation; K − 1 or fewer shares reveal nothing at all about it, not even a single bit. Shares are hex of the y-bytes followed by one byte for x — the same format as the audited shamir-secret-sharing library (Privy) and HashiCorp Vault, so shares are interchangeable with them. There is no integrity check: combining wrong or too few shares gives garbage, not an error.