Storage Device, Storage Method, and Image Display Device

• US 20080052536A1
• Filed: 07/08/2005
• Published: 02/28/2008
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ichikawa, Akio, Ohno, Ryoji, Shimizu, Yukitaka
• Granted Patent: US 8,307,448 B2
• Time in Patent Office: Days
• US Class Current: 713/193
• 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 data in a removable recording medium, comprising:

an encrypting section to encrypt data whose storage period is limited; and

a storage control section that stores the encrypted data in the recording medium and stores the license information including both decryption information required to decrypt the encrypted data and expiration date information for limiting storage period of the data in a fixed secure region of the recording medium.

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

the storage control section counts the period for which the data is stored in the recording medium and updates expiration date information of the data in accordance with the period counted.

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

the storage control section is enabled to store the data together with attribute information for identification of the data in the recording medium.

4. The storage device as defined in claim 3, wherein

the storage control section deletes the data whose expiration date is expired when the storage device is initialized.

5. The storage device as defined in claim 1, comprising:

a reception section to receive broadcasting data on which copy control information is superimposed, wherein

the storage control section generates license information of the data encrypted by the encrypting section from the copy control information and stores the generated license information in the secure region.

6. A storage method for storing data in a removable recording medium, comprising the steps of:

encrypting data whose storage period is limited; and

storing the encrypted data in the recording medium and storing license information including both decryption information required to decrypt the encrypted data and expiration date information for limiting storage period of the data, in a fixed secure region of the recording medium.

7. An image display device having an input/output unit to removably connect a recording medium and a storage unit to temporarily store data in the recording medium, wherein

the storage unit comprises:

an encrypting section to encrypt data whose storage period is limited; and

a storage control section that stores the encrypted data in the recording medium and stores license information including both decryption information required to decrypt the encrypted data and expiration date information for limiting storage period of the data, in a fixed secure region of the recording medium.

8-11. -11. (canceled)