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:
Nov. 16, 2004
Filed:
Apr. 06, 2000
Takumi Okaue, Kanagawa, JP;
Yoshihito Ishibashi, Tokyo, JP;
Yukihiro Sakamoto, Kanagawa, JP;
Asami Mizuno, Kanagawa, JP;
Nobuyuki Kihara, Tokyo, JP;
Teppei Yokota, Chiba, JP;
Sony Corporation, Tokyo, JP;
Abstract
A security unit to prevent unauthorized retrieval of data includes an encrypting unit for encrypting data in accordance with commands received by the security unit, and a common register for storing both intermediate results and final results of the data encryption. A switching element operatively coupled to the register selectively outputs the contents of the register. The switching element is controlled to prevent external access to the intermediate results of the encryption. The security unit is particularly useful as part of a memory unit that is attachable to a recording/reproduction device such as a digital audio recorder/player.