Method and apparatus for controling access to storage media

Abstract

A method and apparatus for preventing copying of data from optical disks. A locus on optical disk is initially read to produce a signal and is then re-read by a reader to produce a second signal. The signal detected upon re-reading is different from the signal that is detected upon initial sampling. A method and apparatus for controlling access to an optical disk, such as an optically readable disk. Light sensitive or other materials that are adapted to change state and affect reading of an optical disk are used to control access to data that may be stored on optical disk and / or to control use of the optical disk.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a continuation application of U.S. patent application Ser. No. 11 / 005,257, filed Dec. 6, 2004, which is a continuation-in-part of U.S. patent application Ser. No. 10 / 645,078, filed Aug. 21, 2003, which is a continuation of U.S. patent application Ser. No. 09 / 631,585, filed Aug. 3, 2000, the contents of which are incorporated herein by reference in their entirety.FIELD OF THE INVENTION [0002] The present invention relates to controlling access to storage media, such as data recorded on optical media. BACKGROUND OF THE INVENTION [0003] Optically readable storage media, such as music and software CD's and video DVD's, provide inexpensive ways to share and disseminate digital information, making such media the media of choice among both producers and consumers. This is clearly evident as CDs have nearly replaced cassette tapes and floppy disks in the music and software industries and DVDs have made significant inroads in replacing v...

AI Technical Summary

Benefits of technology

[0009] Embodiments of the invention enable control of access to storage media, such as optical disks. A material may be provided on the media that is alterable between at least two states, wherein at least one of the states affects whether or how data is read from the media. The material may represent information, such as a conventional barcode represents information on a package, or an encryption / decryption key, or the presence of the material alone may allow access to the media. The material may prevent reading data from a medium, or alter a result of reading data from a medium, e.g., while the material is in one state a data bit “1” may be read, but while the material is in another state a data bit of “0” may be read. The material may be permanent to allow authorized access to the medium for its normal expected lifetime, or temporary such that the material prevents access to the medium when it is no longer detectable after a certain amount of time or a number of reads of the medium.

[0010] Aspects of the invention may also provide for secure downloads of data as well as provide for “uncopyable copies” of data that has been legitimately downloaded from a source. Aspects of the invention may be used to limit the number of times software may be installed or the location of the installation of software. The material may be used to provide dynamic watermarking of data, or used to uniquely identify a specific storage medium.

[0015] In another aspect of the invention, an optical medium containing a pattern of light sensitive material may be placed in a reader attached to a computer where the pattern of light sensitive material may be detected. A data file, for example a movie or audio file, may then be downloaded from a network to the computer in a form that is unplayable in the absence of the code provided by the light sensitive material on the medium. This may allow for the download of digital files such as movies, over the Internet, that result in playable copies only when recorded onto media that contain the proper sequence of light sensitive material in or on the medium. The system may, for example, prevent the downloading of a digital data file without a properly encoded disk, or in another embodiment, may result in an unplayable copy if not downloaded onto an appropriate disk.

[0018] In another embodiment, access, copying and unauthorized installation of digital data may be prevented by placing light sensitive material in the light path of the reader so that the light sensitive compound interferes with the reading of the underlying data. For example, instructions provided to authorized users of a software program may instruct an installation program to read a specific track and then to wait a specified time to access an adjacent track. Absent these instructions, a light sensitive material will have been activated upon reading the first track and will interfere with the reading of adjacent, or nearby, tracks, for a period of time equal to the time of persistence of the light sensitive material. Thus, authentic reading or installation instructions will provide a map for avoiding these traps. Areas of light sensitive material may be large enough to defeat sophisticated error-correction programs, such as EFM and parity bit correction techniques known to those of skill in the art.

[0020] Light sensitive material may be placed on a medium in a pattern that provides a code to unlock access to data stored on the medium, or elsewhere, such as from an attached data storage device. Thus, the coded optical medium may be used as an uncopyable key to provide access to data, files and information. The light sensitive material may be placed on the medium so that, upon reading, a unique data string is produced that allows the data files to be opened. The data string may be a function of, for example, emission, absorption, wavelength shift, time delay, persistence or intensity of the light sensitive material. Thus, a wide variety of variables may be used with a single medium to provide a sophisticated code. For example, an unscrupulous copyist may try to decode a medium by determining where on the medium delayed emission compounds have been placed. However, other variables such as absorbing compounds, compounds exhibiting different persistence, and compounds emitting at different intensities may be used to further thwart the copyist. Alternatively, the code may be simple, such as the placement of a single spot of light sensitive material on the medium.

Problems solved by technology

However, the material may provide a delayed, persistent response that can be detected upon a later reading.

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