The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 2006
Filed:
Apr. 07, 1999
Ryuji Ishiguro, Tokyo, JP;
Masafumi Minami, Tokyo, JP;
Ryuji Ishiguro, Tokyo, JP;
Masafumi Minami, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
Information to be recorded is encrypted using an encryption key based on information inherent in a recording medium. The information inherent in the recording medium is specific information on a disk. When an encrypted information recorded on a recording medium is decrypted, there are reproduced from a recording medium a first file storing information encrypted by using an encryption key generated based on a random data to be inserted into a predetermined portion of the encrypted information to be recorded on a recording medium and a second file storing data indicative of a predetermined portion of the random data to be inserted into a predetermined portion of the encrypted information. The random data is detected from the encrypted information. A decryption key is generated from the detected random data. The encrypted information of the reproduced first file is decrypted using the decryption key.