US 7,689,100 B2Granted

Digital signal recording/reproducing apparatus

AssigneeHitachi, Ltd.

InventorsManabu Sasamoto, Hiroo Okamoto, Toshifumi Takeuchi, Masaru Takahashi

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Abstract

A digital signal recording apparatus is disclosed, which is capable of protecting the copyright of the analog input information encoded into a first digital signal in a recording medium. A second digital signal encrypted based on the key information and the input analog signal encrypted based on the key information are converted into a second digital signal and encrypted, and the resulting signal is selectively recorded in a recording medium. The digital signal recording apparatus further comprises a circuit for encrypting the digital signal converted from the input analog signal with a key obtained by a predetermined calculation of the key information according to a scheme similar to the second digital signal protection scheme through a digital interface, and a signal recording circuit for recording the key information and the encrypted digital signal in a recording medium.

Claims9

Dependent claims

A digital signal recording apparatus comprising:

a first input circuit which inputs an analog signal;
a converter which converts said analog signal into a first digital signal;
a tuner circuit which receives a digital broadcasting information signal and converts said digital broadcasting information signal into a second digital signal;
and
a recording circuit which records at least one of said first digital signal and said second digital signal in a predetermined area of a recording medium;
wherein said recording circuit enables generation of key information and enables updating of said key information, and performing a predetermined calculation with said key information to generating a key, and encrypting said first digital and said second digital signal with said key and recording at least one of said first digital signal and said second digital signal, which is encrypted with a compatible method, together with said key information in a predetermined area on said recording medium, and
wherein said first digital signal and said second digital signal have a packet format of a predetermined length.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/928,242Filed 30 Aug 2004 · continuation
Priority: JP 11-13233113 May 1999
Published: US 2005/0025458 A13 Feb 2005
Granted: 30 Mar 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04N 5/913
Television signal processing therefor: for scrambling ; for copy protection
H04L 9/0869
Generation of secret information including derivation or calculation of cryptographic keys or passwords: involving random numbers or seeds
H04L 2209/605
Digital content management, e.g. content distribution: copy protection
H04N 9/7921
Processing of colour television signals in connection with recording: for more than one processing mode