High security evolutive coding process and device for carrying out this process

• US 4,922,533 A
• Filed: 10/29/1987
• Issued: 05/01/1990
• Est. Priority Date: 10/31/1986
• Status: Expired due to Term

• Current Assignee: N E I M A N
• Original Assignee: N E I M A N
• Inventors: Philippe, Patrick
• Primary Examiner(s): Buczinski, Stephen C.
• Assistant Examiner(s): GREGORY, BERNARR E
• Application Number:
  US07/114,005
• Time in Patent Office: 915 Days
• Field of Search: 380/46, 380/35, 380/28, 375/1, 358/263
• US Class Current: 380/46
• CPC Class Codes: G07C 2009/0023 with encription of the transmittted data signal
• CPC Class Codes: G07C 2009/00253 dynamically, e.g. variable code - rolling code
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: H04L 9/0869 involving random numbers or seeds

Abstract

An evolutive coding process using a pseudo-random discontinuous function for coding remote controls, such as for automobiles. A message containing at least two pseudo-random values calculated by the pseudo-random discontinuous function is transmitted. Preferably the pseudo-random values are successive values of the pseudo-random discontinuous function, and the message optionally includes a code derived as a function of a specific base code associated with the system. The general preferred form of complete code message may take the form T(C) plus FA(C,n-1), plus FA(C,n) where T is a continuous function and FA is a pseudo-random discontinuous function.

Claims

1. An evolutive code process using a pseudo-random discontinuous function, wherein a message containing at least two pseudo-random values calculated by said function is transmitted and wherein further the message contains, in addition, a code calculated by calculation of a continuous function of a specific base code for each system.

2. A process according to claim 1, wherein said pseudo-random values are successive values of said pseudo-random discontinuous function.

3. A device for carrying out an evolutive process according to claim 1, comprising means for transmitting a message containing at least two pseudo-random values calculated by said function and wherein the message contains, in addition, a code calculated by calculation of a continuous function of a specific base code for each system.

4. A device according to claim 3, wherein said pseudo-random values are successive values of said pseudo-random discontinuous function.