Remote control security system

• US 5,604,488 A
• Filed: 08/11/1995
• Issued: 02/18/1997
• Est. Priority Date: 04/10/1992
• Status: Expired due to Fees

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Lambropoulos, George P.
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US08/514,398
• Time in Patent Office: 557 Days
• Field of Search: 340/825.3, 340/825.31, 340/825.32, 340/825.69, 340/825.72, 380/21, 380/28, 380/36, 380/37, 380/49, 380/43, 380/23, 371/37.7
• US Class Current: 340/5.26
• CPC Class Codes: G07C 2009/00253 dynamically, e.g. variable code - rolling code
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: H04K 1/00 Secret communication

Abstract

A remote control keyless security system for remotely controlling the locking and unlocking control functions of a lock mounted on a vehicle or the like. A receiver is mounted on a vehicle proximate to the lock to be controlled. A transmitter is located remote from the receiver and includes a plurality of selectively actuatable switches each representative of a control function to be performed by the lock and circuitry responsive to actuation of one of the switches for transmitting a digital signal including a first portion having a multi-bit security code uniquely identifying the transmitter from that of a plurality of similar transmitters, a multi-bit sequence control code adapted to be sequentially changed in response to each actuation of a switch and a multi-bit function code identifying one of a plurality of control functions to be performed by the lock. The transmitter changes the sequence control code after each operation with the change being dependent upon information contained in the security code identifying the transmitter. The receiver stores a multi-bit receiver security code identifying a specific transmitter from which the receiver may validly receive a digital signal. The received security code is compared with the stored receiver security code to determine whether the security codes match. The receiver also stores a multi-bit sequence control code.

Claims

1. A method of operating a portable transmitter to remotely control at least one function on a vehicle in a secure manner, comprising the steps of:

providing a manually operable switch on said transmitter for use in manually signalling that a function on the vehicle is to be operated;

generating a message for transmission to the vehicle for controlling a function on the vehicle in response to operation of the manually operable switch;

generating an error detecting code based upon said message for use in detecting errors in transmission of said message;

scrambling said message in dependence upon the generated error detecting code and one of a fixed plurality of scrambling algorithms and wherein said error detecting code is generated for a primary purpose unrelated to any of said scrambling algorithms but wherein a secondary purpose is to describe said one of a fixed plurality of scrambling algorithms for selection in accordance with said error detecting code; and

transmitting the scrambled message and the unscrambled error detecting code to said vehicle.

2. A portable transmitter for remotely controlling at least one function on a vehicle in a secure manner, comprising:

a small, hollow transmitter housing adapted for easy transportation in a person'"'"'s pocket;

a manually operable switch mounted in said housing and manually operable from the outside of said housing to control operation of the function;

electronic means contained within said housing and responsive to said switch for (a) generating a message for transmission to the vehicle for controlling a function on the vehicle, (b) generating an error detecting code based upon said message for use in detecting errors in transmission of said message, (c) scrambling said message in dependence upon the generated error detecting code and one of a fixed plurality of scrambling algorithms and wherein said error detecting code is generated for a primary purpose unrelated to any of said scrambling algorithms but wherein a secondary purpose is to describe said one of a fixed plurality of scrambling algorithms for selection in accordance with said error detecting code and (d) transmitting the scrambled message and the unscrambled error detecting code to said vehicle; and

portable power source means contained within said housing for powering said electronic means.

3. A portable transmitter for remotely controlling at least one function on a vehicle in a secure manner, comprising:

a small, hollow transmitter housing adapted for easy transportation in a person'"'"'s pocket;

a manually operable switch mounted in said housing and manually operable from the outside of said housing to control operation of the function;

electronic means contained within said housing and responsive to said switch for (a) generating a message for transmission to said vehicle, said message containing a control code indicative of the desired operation and a security code uniquely identifying said transmitter, (b) generating an error detecting code based upon said message for use in detecting errors in transmission of said message, (c) scrambling said message in dependence upon the generated said error detecting code and one of a fixed plurality of scrambling algorithms and wherein said error detecting code is generated for a primary purpose unrelated to any of said scrambling algorithms but wherein a secondary purpose is to describe said one of a fixed plurality of scrambling algorithms for selection in accordance with said error detecting code, and (d) transmitting the scrambled message and the unscrambled error detecting code to said vehicle; and

portable power source means contained within said housing for powering said electronic means.