The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 12, 2010
Filed:
Apr. 16, 2004
Ralph Kurt, Eindhoven, NL;
Robert Frans Maria Hendriks, Eindhoven, NL;
Levinus Pieter Bakker, Eindhoven, NL;
Ralph Kurt, Eindhoven, NL;
Robert Frans Maria Hendriks, Eindhoven, NL;
Levinus Pieter Bakker, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
The present invention relates to a system for copy protection of an information carrier, said system comprising a diffractive layer for delivering a speckle pattern when illuminated by a light source, a spatial filter, which is aligned with respect to the diffractive layer, for delivering a filtered optical signal from the speckle pattern and a detector array for delivering, when illuminated by said filtered optical signal, an electrical signal. Said system further comprises means for computing a cryptographic key from the electrical signal, and means for decrypting encrypted data contained in the information carrier from the cryptographic key. It finds its application in copy protection of content carriers such as optical discs or in smart cards.