Cagent Technologies, Inc.

Craig A Nelson

Sandro Hermann Pintz

Louis A Cardillo

Glenn J Keller

Hedley C Davis

Landau F Edouard

Authentication mechanism for interactive home entertainment systems using plug-in cards which do contain software as well as cards which do not contain software. A security bit stream is generated by circuitry on the card and checked by the base system while the system is operating, but only a single signal line of the interface is used for the bit stream. The card also includes a ROM which contains data to be downloaded to the base system. The ROM data is downloaded to the base system via the same signal line of the interface as the serial bit stream. The signal line is used for ROM data download while the base system asserts a 'reset' signal, and is used to carry the serial bit stream for authentication purposes whenever the reset signal is negated.

Peripheral card security and configuration interface

Copy-protected optical disk format, optical disk recording apparatus for creating disks having such formats and optical disk reading apparatus for reading disks having such formats and for determining whether the disks are authentic. In one aspect, an authentic optical disk has data bit indications along a spiral centerline of the disk, and these data bit indications define a radial wobble which has substantially greater energy at a predefined frequency f.sub.CPW (such as f.sub.CC /392) than at a frequency of f.sub.CC /196, where f.sub.CC is the spatial channel clock frequency. In another aspect, an authorized optical disk has data bit indications along a substantially spiral centerline of the disk, according to a channel clock whose frequency varies across the disk. The disk further has stored thereon an indication of the number of such channel clock cycles which occur along a predetermined test segment of the centerline, optionally together with a pointer to the test segment. Since normal data stream copying techniques do not copy the exact channel clock rates on the disk, and since the copying equipment will inherently introduce its own channel clock variations across the resulting disk, the predetermined test segment on the copy will not have the number of channel clocks as that specified by the data indicating the number of channel clock cycles to expect along the test segment.

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Aptos, CA, United States of America

Craig A Nelson