SYSTEM AND METHOD FOR AUTHORIZED COMPRESSION OF DIGITIZED MUSIC

• US 20020161714A1
• Filed: 11/24/1999
• Published: 10/31/2002
• Est. Priority Date: 11/24/1999
• Status: Active Grant

• Current Assignee: LinkedIn Corporation (Microsoft Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: BELL, ALAN EDWARD, LOTSPIECH, JEFFREY BRUCE
• Granted Patent: US 7,082,413 B2
• Time in Patent Office: Days
• US Class Current: 705/57
• 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 20/00123 the record carrier being identified by recognising some of its unique characteristics, e.g. a unique defect pattern serving as a physical signature of the record carrier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00884 involving a watermark, i.e. a barely perceptible transformation of the original data which can nevertheless be recognised by an algorithm

Abstract

A system and method for enabling authorized music from a CD or DVD to be compressed by a user for the user'"'"'s own use, but to prevent the recompression of unauthorized music from, e.g., the Internet, includes hashing the music during recording with a cryptographic hash, and then signing the hash with a digital signature derived from the hash. Subsequent unauthorized compression and recompression will destroy the digital signature. Accordingly, music to be recorded is hashed to obtain a test digital signature and if, after hashing, the test digital signature matches the digital signature accompanying the music, compression and recording are allowed to proceed.

Claims

1. A computer-based system for inhibiting unauthorized recording of digitized music, comprising:

a cryptography module including logic executable by a provider computer, the logic including, for at least a segment of the music, obtaining an authorized digital signature, and then associating the authorized digital signature with the music; and

a consumer module associated with a consumer music player and executable thereby to undertake logic including processing at least the segment of the music to obtain a test digital signature, and, only if the test digital signature matches the authorized digital signature, permitting at least one of;

compression of the music, and recording the music, on the consumer music player;

2. The system of claim 1, wherein the cryptography module derives authorized digital signatures for respective plural segments of the music, and associates the authorized digital signatures with the music.

3. The system of claim 2, wherein the consumer module determines test digital signatures for respective plural segments of the music, the consumer module preventing at least one of:

compression of the music, and recording of the music, unless a predetermined relationship exists between test digital signatures and the authorized digital signatures.

4. The system of claim 1, wherein the music is stored in a data stream on a disk, and the authorized digital signature is associated with the music by storing the authorized digital signature on the disk, apart from the stream.

5. The system of claim 1, wherein the music is stored in a data stream on a disk, and the authorized digital signature is associated with the music by storing the authorized digital signature on the disk as part of the stream.

6. The system of claim 1, wherein the authorized digital signature is tagged with a signature date, and the consumer module processes the music using a current key or an expired key having a key date equal to or later than the signature date.

19. The system of claim 4, further comprising a robust watermark on the disk.

7. A computer program storage device including a program of instructions for determining whether a request to compress and record digitized music should be honored, the program of instructions including:

computer readable code means for processing at least one segment of the music to obtain a test digital signature;

computer readable code means for receiving an authorized digital signature associated with the music; and

computer readable code means for permitting compression and recording of the music only if at least the test digital signature matches the authorized digital signature.

8. The device of claim 7, further comprising:

computer readable code means for determining test digital signatures for respective plural segments of the music; and

computer readable code means for preventing at least one of;

compression of the music, and recording of the music, unless a predetermined number or percentage of matches exist between test digital signatures and authorized digital signatures.

9. A computer program storage device including a program of instructions for associating digitized music with at least digital signature derived from at least a segment of the music, the program of instructions including structure comprising:

computer readable code means for deriving an authorized digital signature from at least the segment of the music;

computer readable code means for storing the music on a recording medium; and

computer readable code means for storing the authorized digital signature on the recording medium along with the music.

10. The device of claim 9, further comprising:

computer readable code means for deriving authorized digital signatures for respective plural segments of the music; and

computer readable code means for associating the authorized digital signatures with the music.

11. The device of claim 10, further comprising:

computer readable code means for storing the music on a location of the recording medium apart from the stream.

12. The device of claim 10, further comprising:

computer readable code means for storing the music on a location of the recording medium as part of the stream.

14. The method of claim 13, further comprising the acts of:

deriving plural authorized digital signatures from respective segments of the music; and

recording the plural authorized digital signatures on the disk.

15. The method of claim 14, further comprising the acts of:

deriving plural test digital signatures from plural segments of the music; and

undertaking the compressing and recording act only if a predetermined number or percentage of matches exist between test digital signatures and authorized digital signatures.

16. The method of claim 13, wherein the authorized digital signature is stored on the disk, apart from the music.

17. The method of claim 13, wherein the authorized digital signature is stored on the disk in the music.

18. The method of claim 13, wherein the authorized digital signature is tagged with a signature date, and the deriving act includes processing the music using a current key or an expired key having a key date equal to or later than the signature date.

21. The method of claim 13, further comprising recording a robust watermark on the disk.

13. A method for facilitating the compression and storage, on a personal music player, of digitized music received on a disk in an authorized transaction, comprising the acts of:

recording the music on the disk along with at least one authorized digital signature derived from the music;

receiving the disk;

engaging the disk with a personal music player compression device;

deriving at least one test digital signature from the music; and

compressing the music and recording the music on the personal music player only if the test digital signature matches the authorized digital signature.