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. 07, 1992
Filed:
Nov. 27, 1990
Applicant:
Inventors:
Assignees:
Hitachi Ltd., both of, JP;
Hitachi Control Systems, Inc., both of, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ; H04L / ;
U.S. Cl.
CPC ...
380 28 ; 380 29 ; 380 50 ; 380 23 ; 380 25 ; 235380 ;
Abstract
There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like and a decipher method of deciphering the ciphertext made by the encipher method at a high speed by using the encipher keys. The encipher method and the decipher method are suitable for, particularly, a 32-bit microcomputer and include a process expressed by the function Rot.sub.2 i(x) (i=2, 3, 4) in each process. Rot.sub.2 i(x) is the process to circular shift a data train x of 32 bits to the left or right by 2.sup.i bits (i=2, 3, 4).