Countermeasure method and system for securing a remote keyless entry system

• US 5,883,443 A
• Filed: 06/27/1997
• Issued: 03/16/1999
• Est. Priority Date: 06/27/1997
• Status: Expired due to Fees

• Current Assignee: Lear Automotive Dearborn, Incorporated (Lear Corporation)
• Original Assignee: UT Automotive Dearborn, Inc.
• Inventors: Wilson, Mark M.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Ganjian, Peter
• Application Number:
  US08/884,576
• Time in Patent Office: 627 Days
• Field of Search: 307/9.1, 307/10.1, 307/10.2, 307/10.3, 307/10.4, 307/10.5, 180/287, 340/425.5, 340/426, 340/825.3, 340/825.31, 340/825.32, 340/825.34, 340/825.54, 340/825.69, 340/825.72, 340/825.56, 701/2, 123/198 B, 70/51, 70/237, 70/256, 70/257, 380/23, 380/24, 380/25
• US Class Current: 307/10.2
• CPC Class Codes: B60R 25/04 operating on the propulsion system, e.g. engine or drive motor
• CPC Class Codes: B60R 25/2072 with means for preventing jamming or interference of a remote switch control signal
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2209/04 Access control involving a hierarchy in access rights
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: H04K 2203/22 for communication related to vehicles
• CPC Class Codes: H04K 3/224 with countermeasures at transmission and/or reception of the jammed signal, e.g. stopping operation of transmitter or receiver, nulling or enhancing transmitted power in direction of or at frequency of jammer
• CPC Class Codes: H04K 3/822 by detecting the presence of a surveillance, interception or detection
• CPC Class Codes: H04K 3/92 related to allowing or preventing remote control

Abstract

The present invention teaches a method for preventing the use of an unauthorized reproduction of a remote unlock signal. In this scenario, the unauthorized reproduction occurs by jamming the receiver from receiving the remote unlock signal while intercepting the remote unlock signal. Generally, the remote unlock signal is transmitted by a transmitter to the receiver within a vehicle having a lock, wherein the receiver initiates an unlock command in response to receiving the transmitted remote unlock signal, and the vehicle lock being mechanically actuated by a key or electronically initiated by the unlock command in a previous locking session. The method for preventing the use of an unauthorized reproduction of a remote unlock signal comprises the steps of sensing whether the vehicle lock is being mechanically actuated by the key in the previous locking session, generating a flag if the vehicle lock has been mechanically actuated by the key, and disabling the receiver from initiating the unlock command in response to receiving the remote unlock signal transmitted by the transmitter if the flag is generated.

Claims

1. A method for preventing access to a vehicle using an unauthorized reproduction of a remote unlock signal that is transmitted by a transmitter to a receiver supported by the vehicle having a lock, the receiver initiating an unlock command in response to receiving the transmitted remote unlock signal, the vehicle lock being mechanically actuated by a key or electronically initiated by the unlock command in a previous unlocking session, the method comprising the steps of:

sensing whether the vehicle lock has been mechanically actuated by the key in the previous unlocking session;

generating a flag if the vehicle lock has been mechanically actuated by the key in the previous unlocking session; and

disabling the receiver from initiating the unlock command in response to receiving the remote unlock signal transmitted by the transmitter if said flag is generated.

2. The method of claim 1, further comprising the steps of:

generating a warning signal if the receiver is disabled and said flag is generated.

3. The method of claim 2, wherein said warning signal comprises at least one of blowing a horn, triggering an alarm, flashing of lights, and initiating a camera for recording images.

4. The system of claim 2, further comprising the step of:

transmitting said warning signal to the transmitter.

5. The method of claim 1, wherein the receiver is disabled from initiating the unlock command

in a subsequent unlocking session, in response to a further remote unlock signal transmitted by the transmitter of said flag is generated.

6. A method for preventing access to a vehicle using an unauthorized reproduction of a first encrypted rolling code signal from a set of encrypted rolling code signals comprising a function unlock code and being transmitted by a remote transmitter to a receiver supported on the vehicle having a lock mechanically actuated by a key or electronically initiated by an unlock command in a previous unlocking session, the receiver initiating the unlock command in response to receiving the function unlock code, the method comprising the steps of:

sensing whether the vehicle lock has been mechanically actuated by the key in the previous unlocking session;

setting a first flag if the vehicle lock has been opened mechanically in the previous unlocking session in response to said sensing step;

disabling the receiver from initiating the unlock command in response to the first encrypted rolling code signal being retransmitted if said first flag is generated; and

generating a warning signal if the receiver is disabled and said first flag is generated.

7. The method of claim 6, wherein said warning signal comprises at least one of blowing a horn, triggering an alarm, flashing of lights, and initiating a camera for recording images.

8. The system of claim 6, further comprising the step of:

transmitting said warning signal to the transmitter.

9. The method of claim 6, further comprising the step of:

disabling the receiver from initiating the unlock command, in a subsequent unlocking session, in response to a subsequent encrypted rolling code signal transmitted by the transmitter if said first flag is generated.

10. A system for preventing access to a vehicle using an unauthorized reproduction of a remote unlock signal that is transmitted by a transmitter to a receiver supported by the vehicle having a lock, the receiver initiating an unlock command in response to receiving the transmitted remote unlock signal, the vehicle lock being mechanically actuated by a key or electronically initiated by the unlock command in a previous unlocking session, the system comprising:

a sensor for determining whether the vehicle lock has been mechanically actuated by the key in the previous unlocking session; and

a processor for generating a flag if the vehicle lock has been mechanically actuated by the key in the previous unlocking session, and for disabling the receiver from initiating the unlock command in response to receiving the remote unlock signal transmitted by the transmitter if said flag is generated.

11. The system of claim 10, where said processor generates a warning signal if the receiver is disabled and said flag is generated.

12. The system of claim 11, wherein said warning signal comprises at least one of blowing a horn, triggering an alarm, flashing of lights, and initiating a camera for recording images.

13. The system of claim 11, wherein said warning signal is transmitted by the receiver to the transmitter.

14. The system of claim 10, wherein said processor disables the receiver from initiating the unlock command, in a subsequent unlocking session, in response to a further remote unlock signal transmitted by the transmitter if said flag is generated.