Master digital data creation device and digital data reproduction device

• US 7,076,063 B2
• Filed: 06/04/2001
• Issued: 07/11/2006
• Est. Priority Date: 06/06/2000
• Status: Expired due to Term

• Current Assignee: Rakuten Group, Inc.
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Kuroiwa, Toshio
• Primary Examiner(s): Sheikh, Ayaz
• Assistant Examiner(s): Baum, Ronald
• Application Number:
  US09/871,905
• Publication Number:
  US 20010049665A1
• Time in Patent Office: 1,863 Days
• Field of Search: 380201-203, 705 50- 59
• US Class Current: 380/201
• CPC Class Codes: G06F 21/109 by using specially-adapted hardware at the client
• 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 20/00746 wherein the usage restriction can be expressed as a specific number
• CPC Class Codes: H04N 1/32128 attached to the image data, e.g. file header, transmitted message header, information on the same page or in the same computer file as the image for information embedded in the image H04N1/32144
• CPC Class Codes: H04N 2201/3246 of data relating to permitted access or usage, e.g. level of access or usage parameters for digital rights management [DRM] related to still images
• CPC Class Codes: H04N 2201/3274 Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 2201/3278 Transmission
• CPC Class Codes: H04N 2201/3281 Encryption; Ciphering

Abstract

Data C generated by scrambling user-desired digital data P and a control word CW_p corresponding to the number of reproductions p are recorded on recording media. When creating a master, a user has already been charged for the number of reproductions p. A decryption block decrypts the control word CW_p, which is read from the recording media, to CW₀. A de-scrambler uses the decryption control word CW₀ to decrypt the digital data P for output to a reproduction unit. After confirming the end of reproduction, the decryption block writes a control word CW_(p−1) back to the recording media. The recording media may be reproduced p times with no need for communication between a reproduction device and an accounting manager.

Claims

1. A master digital data creation device for supplying second digital data obtained by scrambling first digital data to a digital data reproduction device having a recording medium, comprising:

an encryption block generating a first control word for identifying an allowable number of reproductions specified by the digital data reproduction device and applying a one-way function to the first control word a number of times corresponding to the allowable number of reproductions to generate a second control word for scrambling the first digital data and representing a number of times said first digital data has been reproduced;

a scrambler receiving the second control word and using the second control word to produce the second digital data; and

an output block outputting the second digital data and the first control word to the digital data reproduction device.

2. A digital data reproduction device comprising:

an acceptor accepting recording media on which first digital data and a first control word are recorded, said first control word being generated based on a specified allowable number k of reproductions and being an identifier of said allowable number k of reproductions, said first digital data having been generated by scrambling desired second digital data using a second control word having been generated by applying a one-way function to the first control word k times;

a decryption block receiving the first control word and applying the one-way function to the first control word k times to produce the second control word;

a de-scrambler receiving the first digital data and the second control word and de-scrambling the first digital data using the second control word to produce the second digital data; and

a reproduction unit reproducing the second digital data generated by said de-scrambler,

wherein, after every reproduction by said reproduction unit, said decryption block writes a third control word back to said recording media representing a remaining number of allowable reproductions of said second digital data, said third control word being generated by applying the one-way function to the first control word once, and wherein, if the first control word received from the recording media equals the second control word, the de-scrambling by said de-scrambler and the reproduction by said reproduction unit are inhibited.

3. The digital data reproduction device according to claim 2, wherein, when a desired number of reproductions, n, is received from some other reproduction device, said decryption block receives the first control word from the recording media and, if k≧

n, applies the one-way function to the first control word (k−

n) times to produce the third control word representing a remaining number of allowable reproductions of said second digital data and applies the one-way function to the first control word n times to produce the fourth control word representing a replacement identifier for said first control world for representing an allowable number of reproductions of said second digital data; and

records the fourth control word on the recording media for updating, further comprising;

an output block outputting the first digital data recorded on the recording media, and the third control word, obtained from the decryption block, to the other reproduction device.