US Patent 7658325 System for authenticating encoded object

A system for authenticating an object is provided having means for sensing coded tags printed on the object which each encode an identity of the object, a signature fragment and a signature fragment identifier associated with the signature fragment, means for identifying a determined signature from the identity, signature fragment and signature fragment identifier encoded by at least one sensed coded tag, means for generating, using the determined signature and a key, a generated identity, means for comparing the identity encoded by the sensed coded tag with the generated identity, and means for authenticating the object using the results of the comparison.