Managing copy protecting information of encrypted data

• US 20080240442A1
• Filed: 10/31/2007
• Published: 10/02/2008
• Est. Priority Date: 03/13/2001
• Status: Active Grant

• Current Assignee: Byuong Jin Kim, Hyung Sun Kim
• Original Assignee: Byuong Jin Kim, Hyung Sun Kim
• Inventors: Kim, Hyung Sun, Kim, Byuong Jin
• Granted Patent: US 7,680,740 B2
• Time in Patent Office: Days
• US Class Current: 380/277
• CPC Class Codes: G06Q 20/382 insuring higher security of transaction
• 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 20/00094 involving measures which result in a restriction to authorised record carriers
• CPC Class Codes: G11B 20/00115 wherein the record carrier stores a unique medium identifier
• CPC Class Codes: G11B 20/0021 involving encryption or decryption of contents recorded on or reproduced from a record carrier
• CPC Class Codes: G11B 20/00224 wherein the key is obtained from a remote server
• CPC Class Codes: G11B 20/00246 wherein the key is obtained from a local device, e.g. device key initially stored by the player or by the recorder
• CPC Class Codes: G11B 20/00507 wherein consecutive physical data units of the record carrier are encrypted with separate encryption keys, e.g. the key changes on a cluster or sector basis
• CPC Class Codes: G11B 20/00673 wherein the erased or nullified data include a cryptographic key
• CPC Class Codes: G11B 20/0071 involving a purchase action
• CPC Class Codes: G11B 20/00818 wherein the usage restriction limits the signal quality, e.g. by low-pass filtering of audio signals or by reducing the resolution of video signals
• CPC Class Codes: G11B 20/00978 wherein the record carrier stores a trial version of a content
• CPC Class Codes: G11B 2220/213 Read-only discs
• CPC Class Codes: H04N 2005/91364 the video signal being scrambled
• CPC Class Codes: H04N 21/42646 for reading from or writing on a non-volatile solid state storage medium, e.g. DVD, CD-ROM
• CPC Class Codes: H04N 21/4622 Retrieving content or additional data from different sources, e.g. from a broadcast channel and the Internet web site content organization and management for information retrieval from the Internet G06F16/958; transmission by internet of broadcast information H04H60/82; stock exchange data over packet-switching network H04L12/1804; push services including data channel over packet-switching network H04L12/1859
• CPC Class Codes: H04N 21/63345 by transmitting keys key distribution for secret or secure communication H04L9/08; network support of key management H04L63/06
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/85 on discs or drums
• CPC Class Codes: H04N 5/913 for scrambling ; for copy protection
• CPC Class Codes: H04N 7/1675 : Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 9/8205 : involving the multiplexing of an additional signal and the colour video signal
• CPC Class Codes: H04N 9/8227 : the additional signal being at least another television signal

Abstract

The present invention provides according to an embodiment a method of reproducing digital content, comprising the steps of: (a) reading a position information where a sample data is present, the sample data being same as a portion of digital content and not encrypted; and (b) reproducing the sample data based on the read position information without a key information, the key information required for decrypting an encrypted digital content.

Claims

1-3. -3. (canceled)

4. A method of reproducing content, comprising:

checking whether a first key information, required to decrypt encrypted digital content is present;

checking whether sample data associated with the encrypted digital content is present to reproduce the sample data without the first key information;

requesting a second key information from an external source based on URL (Uniform Resource Locator) when the first key information is not present; and

reproducing the sample data using the second key information when the sample data is present.

5. A device for reproducing content, comprising:

a controller adapted to check whether a first key information required to decrypt encrypted digital content is present in the device and to check whether sample data associated with the encrypted digital content is present to reproduce the sample data without the first key information; and

a reproducing unit adapted to reproduce the encrypted digital content using the first key information when the first key information is present,

wherein the controller is adapted to request a second key information from an external source based on URL (Uniform Resource Locator) when the first key information is not present so that the reproducing unit reproduces the sample data using the second key information when the sample data is present.

6. A computer readable medium recording software to perform a method for reproducing content, the method comprising:

checking whether a first key information required to decrypt encrypted digital content is present;

checking whether sample data associated with the encrypted digital content is present to reproduce the sample data without the first key information;

requesting a second key information from an external source based on URL (Uniform Resource Locator) when the first key information is not present; and

reproducing the sample data using the second key information when the sample data is present.