Storage device, storage method, and image display device

• US 8,307,448 B2
• Filed: 07/08/2005
• Issued: 11/06/2012
• Est. Priority Date: 07/23/2004
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shimizu, Yukitaka, Ohno, Ryoji, Ichikawa, Akio
• Primary Examiner(s): Homayounmehr, Farid
• Assistant Examiner(s): LEWIS, LISA C
• Application Number:
  US11/632,721
• Publication Number:
  US 20080052536A1
• Time in Patent Office: 2,678 Days
• Field of Search: 726 26- 33
• US Class Current: 726/26
• 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 20/00181 using a content identifier, e.g. an international standard recording code [ISRC] or a digital object identifier [DOI]
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00768 wherein copy control information is used, e.g. for indicating whether a content may be copied freely, no more, once, or never, by setting CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/0084 wherein the usage restriction can be expressed as a specific time or date
• CPC Class Codes: G11B 20/00847 wherein the usage restriction is defined by a licence file
• CPC Class Codes: H04L 2209/60 Digital content management, e.g. content distribution
• CPC Class Codes: H04L 9/088 Usage controlling of secret information, e.g. techniques for restricting cryptographic keys to pre-authorized uses, different access levels, validity of crypto-period, different key- or password length, or different strong and weak cryptographic algorithms network architectures or network communication protocols for using time-dependent keys in a packet data network H04L63/068
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/42669 the medium being removable
• CPC Class Codes: H04N 21/4334 Recording operations recording of a television signal H04N5/76; arrangements for recording or accumulating broadcast information or broadcast-related information H04H60/27
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/4408 involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network
• CPC Class Codes: H04N 21/4623 Processing of entitlement messages, e.g. ECM [Entitlement Control Message] or EMM [Entitlement Management Message] arrangements for conditional access to broadcast information or to broadcast-related services H04H60/14
• CPC Class Codes: H04N 21/835 Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 21/8355 involving usage data, e.g. number of copies or viewings allowed
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection

Abstract

When data whose storage period is limited by copy control information is temporarily stored in a removable recording medium, the data are encrypted and decoding information (encryption key) necessary to decrypt the encrypted data is held on the device side. By doing so, the data cannot be used beyond a permitted period of the temporary storage. A storage device has an external input/output I/F for removably connecting a removable recording medium; a reception section for receiving copy control information and data (such as video data), the storage period of which data is limited by the copy control information; an encrypting section for encrypting the received data; and a control section for storing the encrypted data in the removable recording medium and storing decryption information (encryption key), necessary to decrypt the encrypted data, in a place in the storage device, outside the removable recording medium. The data stored in the removable recording medium can be reproduced only by the storage device.

Claims

1. A storage device storing broadcasting data in a removable hard disk having a tamper resistant module (TRM) region, comprising:

a processor which receives broadcasting data that includes copy control information, the copy control information limits the storage period of the broadcasting data, wherein the receiving section extracts the copy control information from the broadcasting data while the broadcasting data is in the unencrypted state;

the processor encrypts the broadcasting data whose storage period is limited; and

the processor stores the encrypted broadcasting data in the removable hard disk, wherein the processor generates license information including both decryption information required to decrypt the encrypted broadcasting data and expiration date information for limiting storage period of the encrypted broadcasting data in accordance with the copy control information and stores the generated license information in the TRM region of the removable hard disk before storing the encrypted broadcasting data in the removable hard disk, and wherein the processor updates the expiration date information stored in the TRM region of the removable hard disk while the processor stores encrypted broadcasting data in the removable hard disk.

2. The storage device as defined in claim 1, wherein

the processor counts the period for which the broadcasting data is stored in the removable hard disk and updates expiration date information of the broadcasting data in accordance with the period counted.

3. The storage device as defined in claim 1 or 2, wherein the processor is enabled to store the broadcasting data together with attribute information for identification of the broadcasting data in the removable hard disk.

4. The storage device as defined in claim 3, wherein the processor deletes the broadcasting data whose expiration date is expired when the storage device is initialized.

5. A storage method by a storage device for storing broadcasting data in a removable hard disk having a tamper resistant module (TRM) region, comprising the steps of:

receiving broadcasting data that includes copy control information, the copy control information limits the storage period of the broadcasting data by the storage device;

extracting the copy control information from the broadcasting data while the broadcasting data is in an unencrypted state;

generating license information including both decryption information required to decrypt the encrypted broadcasting data and expiration date information for limiting storage period of the encrypted broadcasting data in accordance with the copy control information and storing the generated license information in the TRM region of the removable hard disk,

encrypting the broadcasting data whose storage period is limited; and

storing the encrypted broadcasting data in the removable hard disk,

wherein said step of storing the encrypted broadcasting data is performed after the step of storing the generated license information and includes updating the expiration date information of the broadcasting data and storing the updated expiration date information in the TRM region of the removable hard disk.

6. An image display device having an input/output unit to removably connect a removable hard disk having a tamper resistant module (TRM) region and a storage unit to temporarily store broadcasting data in the removable hard disk, comprising:

a processor that receives broadcasting data that includes copy control information, the copy control information limits the storage period of the broadcasting data;

the processor extracts the copy control information from the broadcasting data while the broadcasting data is in an unencrypted state;

the processor encrypts the broadcasting data whose storage period is limited; and

the processor stores the encrypted broadcasting data in the removable hard disk, wherein

the processor generates license information including both decryption information required to decrypt the encrypted broadcasting data and expiration date information for limiting storage period of the encrypted broadcasting data in accordance with the copy control information and stores the generated license information in the TRM region of the removable hard disk before storing the encrypted broadcasting data in the removable hard disk, and

wherein the processor updates the expiration date information stored in the TRM region of the removable hard disk while the processor stores the encrypted broadcasting data in the removable hard disk.