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:
May. 30, 1995
Filed:
Mar. 03, 1994
Paul A Michaels, Livonia, MI (US);
Lectron Products, Inc., Rochester Hills, MI (US);
Abstract
An encryption process for a rolling code of a remote keyless entry system. The encryption process makes use of a command code shift register, a security code shift register, and a sequence code shift register in which the contents of these registers is transmitted from a portable transmitter to a receiver associated with the vehicle in order to perform a desirable function. The command code shift register provides the code of the function to be performed and the sequence code shift register provides a sequence code for updating the sequence of the receiver. The security code shift register includes a security code which is updated by a first and second pseudo random number generator after each transmission. Each of two pseudo random number generators include associated shift registers and exclusive NOR gates such that a first bit location and a tap bit location of each of the shift registers are exclusively NORed to provide a first bit location in the shift register. A series of the bit locations of the first and second shift registers are exclusively ORed together to set the bits of the security code register.