US Patent 8370638 Derivative seeds

A method of generating authentication seeds for a plurality of users, the method involving: based on a single master seed, generating a plurality of derivative seeds, each one for a corresponding different one of a plurality of users; and distributing the plurality of derivative seeds to a verifier for use in individually authenticating each of the plurality of users to that verifier, wherein generating each one of the plurality of derivative seeds involves mathematically combining the master seed and a unique identifier identifying the corresponding user.