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:
Jan. 30, 2001
Filed:
Aug. 22, 1997
Akio Nakano, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
In a remote control system having a transmitter and a receiver, a rolling code is ciphered to generate a ciphered rolling code by repeating, n times, an exclusive-OR operation on a constant code in a rolling code table and the rolling code as well as an-maximum shift keying. A key code specific to each control system is used as a constant code at the k-th exclusive-OR logic operation so that the k-th exclusive-OR logic operation becomes different from system to system resulting in different ciphering method for each system. The key code is set in an EEPROM in the process of control system production so that the rolling code may not be deciphered even by a design engineer as long as the key code is kept undisclosed.