CD-PROM

• US 5,596,639 A
• Filed: 01/30/1995
• Issued: 01/21/1997
• Est. Priority Date: 07/26/1993
• Status: Expired due to Fees

• Current Assignee: PDACO LIMITED
• Original Assignee: Elonex IP Holdings Limited
• Inventors: Kikinis, Dan
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/380,049
• Time in Patent Office: 722 Days
• Field of Search: 380/3, 380/4, 380/49, 380/23, 380/25
• US Class Current: 705/52
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/629 to features or functions of an application
• CPC Class Codes: G06F 21/80 in storage media based on magnetic or optical technology, e.g. disks with sectors preventing unauthorised reproduction or copying of disc-type recordable media G11B20/00
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• CPC Class Codes: G11B 20/00086 Circuits for prevention of unauthorised reproduction or copying, e.g. piracy indicating unauthorised use of record carriers in general G11B23/28; scrambling for television signal recording H04N5/913; network architectures or network protocols for network security H04L63/00; cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00253 wherein the key is stored on the record carrier
• CPC Class Codes: G11B 20/00492 wherein content or user data is encrypted
• CPC Class Codes: G11B 20/00528 wherein each title is encrypted with a separate encryption key for each title, e.g. title key for movie, song or data file
• CPC Class Codes: G11B 20/00659 involving a control step which is implemented as an executable file stored on the record carrier
• CPC Class Codes: G11B 20/00927 wherein said defects or errors are generated on purpose, e.g. intended scratches
• CPC Class Codes: G11B 20/00949 said intentional errors occurring due to bad sectors, which are either physically destroyed or which are declared defective in the defect management information
• CPC Class Codes: G11B 2220/211 Discs having both read-only and rewritable or recordable areas containing application data; Partial ROM media
• CPC Class Codes: G11B 2220/2545 CDs
• CPC Class Codes: G11B 7/0037 with discs
• CPC Class Codes: G11B 7/00736 Auxiliary data, e.g. lead-in, lead-out, Power Calibration Area [PCA], Burst Cutting Area [BCA], control information sector headers or adresses in prepits G11B7/00745; address data in track wobble G11B7/24082

Abstract

Data on a CD-PROM disk is selectively accessed in a secure manner by selectively encoding binary digital passwords and decryption keys onto the same disk in a separate area. Passwords and decryption keys may be programmed onto the disk after manufacture, such as at the point of sale, by selectively obliterating the readability of bits in addressable sectors. A binary digital key is then later recognized as the result of a string of addressable sectors, with the readable and unreadable sectors providing the digital string. In an embodiment, a manufacturer may place several or all versions and features of a large program on a single CD-ROM, encrypted, and later provide keys to enable only selected ones of the features and versions for retrieval. By programming a password or decryption key over an area of a programming region having a storage capacity of at least a megabyte, and in some cases several megabytes, existing methods of intercepting and defeating such security schemes may be defeated.

Claims

1. A method for providing digital information to a host computer in a secure fashion on a compact disk read-only memory (CD-ROM), wherein information is recorded in physical structure of a recording track, comprising steps of:

(a) providing the digital information in formatted sectors of a recording region on the CD-ROM; and

(b) programming a password into a programming region on the CD-ROM by damaging the physical structure of the recording track in selected sectors in the programming region, forming thereby a sequence of physically damaged and undamaged sectors, the sequence providing the password for use in enabling reading of the digital information in the recording region by a host computer;

wherein the password is recorded over an area of the programming region having a digital storage capacity of at least one megabyte of data storage.

2. The method of claim 1 wherein the password extends over an area of at least four megabytes of data storage.

3. The method of claim 1 wherein the digital information is provided on the CD-ROM in an encrypted fashion requiring a keyword for decryption, and the password programmed into the programming region is the keyword for decrypting the encrypted digital information.

4. The method of claim 1 wherein the digital information comprises plural files, each requiring a separate password to be accessed, and wherein separate passwords are programmed into the programming region for enabling the separate files.

5. The method of claim 3 wherein the digital information comprises plural encrypted files, each requiring a separate keyword to be decrypted, and wherein separate keywords are programmed into the programming region for decrypting the plural encrypted files.

6. A method for providing access control to only individual computer files purchased by a customer of multiple computer files stored on a compact disk read-only memory (CD-ROM), wherein information is recorded in physical structure of a recording track, comprising the steps of:

(a) providing the individual computer files in formatted sectors of a recording region on a compact disk read-only memory (CD-ROM);

(b) programming digital passwords for enabling access to only the computer files purchased by a customer into a programming region of the CD-ROM by damaging the physical structure of the recording track in selected sectors in the programming region, forming thereby a sequence of physically damaged and undamaged sectors;

wherein the passwords are recorded over an area of the programming region having a digital storage capacity of at least one megabyte of data storage.

7. The method of claim 6 wherein the individual files are recorded on the CD-ROM in an encrypted fashion requiring a keyword for decryption, and the password programmed into the programming region is the keyword for decrypting the encrypted digital information.

8. A compact disk read-only memory (CD-ROM), comprising:

a recording region wherein digital information is recorded digitally by physical structure within formatted sectors along a spiral track; and

a programming region having formatted sectors wherein a password is recorded by selectively damaging the physical structure of the data track in selected sectors in the programming region, forming thereby a sequence of physically damaged and undamaged sectors, the sequence providing the password for use in enabling access to the digital information recorded in the recording region;

wherein the password is recorded over an area of the programming region having a digital storage capacity of at least one megabyte of data storage.

9. A compact disk read-only memory as in claim 8, wherein the digital information recorded in the recording region is recorded in an encrypted fashion, and the password recorded in the programming region is a digital keyword for use in decrypting the digital information recorded in the recording region.