Eastman-Kodak Company

William James Mueller

Douglas E Bugner

William J Staudenmayer

Carl R Bothner

Robert V Reisch

Bruce Ha

Alfred J Amell

Bane V Vasic

Donald A Fairman

Larry L Smearer

A hybrid disc including a preformed portion; and the preformed portion including a partial preformed session and a writeable portion including a wobbled groove which is adapted to be written to by a writer to complete the partial preformed session.

System to reduce writing overhead to a hybrid optical disc

The invention provides a method of proving that a CD is an authorized original by utilizing a unique catalog code that is stored in a sub channel data stream on the CD that is derived using digital signature techniques. The inputs for the unique catalog code are derived from a digital signature algorithm and include, in the case of audio CD, each song's ISRC number, a bar code or unique identifier of the CD and the audio data content. To verify that the CD is not a copy, the original digital signature algorithm used at the time of recording to create the unique catalog code is applied to the audio data and ISRC codes recorded on the disc to derive a catalog code. An authorized original CD will have the same catalog code value stored in the subchannel as the catalog code derived from the digital signature algorithm. If the catalog codes do not match, the disc is determined to be an illegal copy.

Method for insuring uniqueness of an original CD

Method and apparatus for preparing, on demand, a selected information

Method and apparatus for preparing labelled digital disc

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Henrietta, NY, United States of America

William James Mueller