COPY CONTROL METHOD

• US 20120066742A1
• Filed: 06/16/2011
• Published: 03/15/2012
• Est. Priority Date: 09/10/2010
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi Consumer Electronics Company Limited (Hitachi, Ltd.)
• Inventors: Tsuruga, Sadao, Okamoto, Hiroo
• Granted Patent: US 8,532,291 B2
• Time in Patent Office: Days
• US Class Current: 726/3
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: G11B 20/00456 digital transmission content protection [DTCP]
• CPC Class Codes: G11B 20/00753 wherein the usage restriction limits the number of copies that can be made, e.g. CGMS, SCMS, or CCI flags
• CPC Class Codes: G11B 20/0076 wherein the copy frequency, i.e. the number of copies in a given time period, is limited
• CPC Class Codes: H04L 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838

Abstract

The usability while performing copy control can be enhanced in the case of recording a digital broadcast program for which recording of one generation is permitted (“Copy One Generation”). When an output route in the case of copying digital contents from a first recording apparatus to a second recording apparatus is via LAN, authentication is executed between the first recording apparatus and the second recording apparatus. The capability of a move process with a predetermined copy number of multiple copies being kept is confirmed, and dedicated key information is shared to be used for encryption and decryption of the digital contents moved with the predetermined copy number of multiple copies being kept. Then, the digital contents recorded and managed in the first recording apparatus is added with the information about the predetermined copy number of multiple copies, and transmitted.

Claims

1. A copy control method for receiving digital contents and copy control information including a first information and a second information which controls copying the digital contents, and for copying the digital contents from a first recording apparatus to a second recording apparatus according to the copy control information, wherein,

when a first information included in the received control information indicates copy generation information permitting “

Copy One Generation”

,

if a second information included in the received copy control information indicates “

Copy Free with Limit of the Number”

permitting a predetermined copy number of multiple copies,

then the digital contents can be recorded and managed in the first recording apparatus in a state where it is permitted to copy the digital contents up to the predetermined copy number, and the digital contents recorded and managed in the first recording apparatus are moved to the second recording apparatus with the predetermined copy number being kept; and

further

if the digital contents are copied from the first recording apparatus through LAN to the second recording apparatus,

then authentication is executed between the first recording apparatus and the second recording apparatus, and a dedicated key information is shared to be used for confirming the capability of move processing with the predetermined copy number being kept and encrypting/decrypting the digital contents moved with the predetermined copy number being kept, and then

the digital contents recorded and managed in the first recording apparatus is added with the information about the predetermined copy number of copies, and transmitted.