Cryptographic Authority
Shamir's Secret Sharing
An algorithm dividing a secret into N shares where any K suffice to reconstruct it — possessing fewer than K reveals nothing.
Definition
A cryptographic algorithm invented by Adi Shamir in 1979 that divides a secret into N shares, any K of which (the threshold) suffice to reconstruct it. Shamir's scheme is information-theoretically secure: possessing fewer than K shares reveals zero information about the secret. It is the mathematical ancestor of modern threshold cryptography and the basis for standards like SLIP-39 used in seed phrase backup systems.