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:
Apr. 10, 2007
Filed:
Dec. 29, 2003
Takashi Endo, Musashimurayama, JP;
Masahiro Kaminaga, Sakado, JP;
Takashi Watanabe, Kokubunji, JP;
Kunihiko Nakada, Koganei, JP;
Takashi Tsukamoto, Kodaira, JP;
Takashi Endo, Musashimurayama, JP;
Masahiro Kaminaga, Sakado, JP;
Takashi Watanabe, Kokubunji, JP;
Kunihiko Nakada, Koganei, JP;
Takashi Tsukamoto, Kodaira, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi ULSI Systems Co., Ltd., Tokyo, JP;
Abstract
An object of the present invention is to prevent secret information that is being internally processed from being inferred through operational information of a secured device, including the current consumption information. One solution is provided by an information processing device having at least a key generation apparatus that generates key data automatically, an encryption unit that encrypts data with the corresponding key data, a register that stores a plurality of encrypted data items with the corresponding encryption key data items, and an arithmetic unit that performs operations using data expressed with the corresponding encryption key data and new key data as the input, encrypts the operation result with new input key data, and outputs the result, thereby being capable of performing internal processing on an encrypted data expression. Accordingly, only encrypted data is transferred on the internal or external data bus line.