A method of authenticating an object is disclosed. Coded data portions are provided on a surface of the object. Each coded data portion encodes a position of coded data portion on the surface, an identity associated with the object and a signature fragment. The signature fragment is a fragment of a digital...http://www.google.de/patents/US20090125723?utm_source=gb-gplus-sharePatent US20090125723 - AUTHENTICATION OF AN OBJECT
