Abstract: A system for authenticating an object on the basis of a repeatably sensible, random magnetic medium or substance deposited on an object, for example in the form of a document. A magnetic medium printed on the document is sensed for its random characteristic which is reduced to a data format that is recorded on the object, e.g. document. Specifically, the repeatably sensible, random characteristic of the magnetic medium is recorded in a digital format on a magnetic stripe of a document so as to identify or verify the document. Conditioning techniques, as depositing and recording the magnetic characteristic medium and selectively sensing it, accomplish various specific objectives.

Abstract: A system for authenticating a document includes a uniqueness characteristic reader to generate a first identifier for the document. The identifier is then encrypted and optionally encoded to define an error correction code. The encrypted identifier and the optional error correction code are combined in accordance with a predefined format to define a code which is stored on the document itself (such as on a magnetic stripe). Authentication of the document is accomplished by reading the code on the item. The code is then processed to identify the location and quantity of any erroneous data. The identified location and quantity information for erroneous data, in conjunction with the optional error correction code, is then utilized to correct all errors in at least the encrypted identifier portion of the code read from the storage medium. The resultant encrypted identifier is therefore retrieved from the storage medium on the item without error.