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:
Dec. 23, 2003
Filed:
Mar. 16, 2001
Masahiro Kaminaga, Sakado, JP;
Takashi Endo, Musashimurayama, JP;
Takashi Watanabe, Kokubunji, JP;
Masaru Ohki, Tokorozawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A tamper-resistant information device for use with IC cards, etc. having high security. The tamper-resistant information device has an input unit for inputting a signal, a storage unit for storing a program, an operation unit for performing predetermined data processing according to a program, and an output unit for outputting a signal. The program stored in the above storage unit includes one or more data processing instructions giving an execution direction to the operation unit. When the signal input from the above data inputting unit is subjected to data processing, at least one of the above data processing instructions instructs an operation on a signal A and a signal B to be performed, where the signal B is used for a given calculation in data processing, the above operation including the steps of: arbitrarily dividing the signal A or B into pieces; performing a given operation on each piece of the divided signal and on the remaining undivided signal, separately; and adding all the operation results to obtain the proper encrypted signal.