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. 11, 1997
Filed:
Dec. 21, 1995
Applicant:
Inventor:
Michio Shimada, Tokyo, JP;
Assignee:
NEC Corporation, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ; H04L / ; H04L / ;
U.S. Cl.
CPC ...
380 42 ; 380-9 ; 380 28 ; 380 29 ; 380 37 ; 380 43 ; 380 49 ;
Abstract
In a product cipher apparatus, a permutation is performed upon plaintext or ciphertext to generate a first message. At least two successive substitutions are performed upon the first message to generate a second message, and the same permutation is performed upon the second message to generate a third message. The successive substitutions and the permutation are repeatedly performed upon the third message to obtain ciphertext or plaintext.