PASSIVE REMOTE KEYLESS ENTRY SYSTEM WITH LEVEL-BASED ANTI-THEFT FEATURE

• US 20150022332A1
• Filed: 07/09/2014
• Published: 01/22/2015
• Est. Priority Date: 07/22/2013
• Status: Active Grant

• Current Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Automotive USLLC (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Lin, Xing Ping
• Granted Patent: US 10,543,808 B2
• Time in Patent Office: Days
• US Class Current: 340/426.1
• CPC Class Codes: B60R 25/00 Fittings or systems for preventing or indicating unauthorised use or theft of vehicles locks for vehicles E05B77/00-E05B85/00
• CPC Class Codes: B60R 25/20 Means to switch the anti-theft system on or off
• CPC Class Codes: G07C 2009/00555 comprising means to detect or avoid relay attacks
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2209/61 Signal comprising different frequencies, e.g. frequency hopping
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

Method for preventing security breaches via the two-thief method of attack of passive remote keyless entry systems for vehicles. The method involves the transmission of a signal between a fob and the vehicle, where the level of the signal changes in a particular pattern. At the receiving side, anomalies in the pattern of the received signal (e.g., levels, timing) are detected and used to detect attempts to mimic the signal.

Claims

1. A method for preventing security breaches of passive remote keyless entry systems for a vehicle comprising the steps of transmitting a signal between a fob and the vehicle at a level which changes in a particular pattern and detecting at the receiving side anomalies in the pattern of the received signal.

2. A method as set forth in claim 1, wherein said step of transmitting a signal between a fob and the vehicle comprises the step of transmitting a signal from said fob to said vehicle at a level which changes in a particular pattern.

3. A method as set forth in claim 2, further comprising the steps of establishing said particular pattern at said vehicle and communicating said particular pattern to said fob.

4. A method as set forth in claim 2, wherein said step of transmitting a signal from said fob comprises the step of transmitting in a particular pattern that includes high level and low level transmissions having levels sufficiently different that it is difficult to receive both high and low level transmissions without reconfiguration of a receiver.

5. A method as set forth in claim 1, wherein said step of detecting anomalies comprises the step of detecting incorrect time delays in said pattern.

6. A method as set forth in claim 1, wherein said step of detecting anomalies comprises the step of detecting incorrect signal amplitudes in said pattern.

7. A method as set forth in claim 6, wherein said step of detecting incorrect signal amplitudes comprises the step of detecting both incorrect relative amplitudes and incorrect absolute amplitudes.

8. A method as set forth in claim 6, wherein said step of detecting anomalies further comprises the step of detecting incorrect time delays in said pattern.

9. A method as set forth in claim 6, wherein said step of detecting anomalies further comprises the step of detecting incorrect frequency content of said pattern.

10. A method as set forth in claim 6, wherein said step of detecting anomalies further comprises the step of detecting incorrect ASK/FSK modulation of said pattern.

11. A method as set forth in claim 1, and further comprising the step of changing said particular pattern each time said fob and said vehicle communicate.

12. A method as set forth in claim 11, wherein said step of changing further comprises the steps of establishing said particular pattern at one of said fob and said vehicle, and communicating said established particular pattern to the other of said fob and said vehicle.

13. A method as set forth in claim 1, and further comprising the step of performing a vehicle function only if there are no unexpected anomalies in said pattern of said received signal.

14. A method as set forth in claim 1, wherein said signal has data modulated thereon and wherein said transmitting step comprises the step of transmitting at a level which changes at a rate that is slower than the rate of said data.

15. A method for preventing security breaches of a passive remote keyless entry system for a vehicle comprising the steps of transmitting a signal from a fob to the vehicle at a level which changes in a particular pattern, receiving said signal at said vehicle, detecting deviations of the received signal from said particular pattern, and performing a vehicle function only if said deviations are within acceptable limits.

16. A method as set forth in claim 15, and further comprising the step of changing said particular pattern each time said fob and said vehicle communicate.

17. A method as set forth in claim 16, wherein said step of changing said particular pattern further comprises the steps of establishing said particular pattern at one of said fob and said vehicle, and communicating said established particular pattern to the other of said fob and said vehicle.

18. A method as set forth in claim 15, wherein said signal has data modulated thereon and wherein said transmitting step comprises the step of transmitting at a level which changes at a rate that is slower than the rate of said data.

19. A method as set forth in claim 15, wherein said step of performing a vehicle function comprises the step of unlocking a vehicle door to allow entry into the vehicle.

20. A method as set forth in claim 15, wherein said step of performing a vehicle function comprises the step of starting the vehicle.