PROTECTION OF NEAR-FIELD COMMUNICATION EXCHANGES

• US 20130130614A1
• Filed: 01/07/2013
• Published: 05/23/2013
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Cubic Corporation
• Original Assignee: Cubic Corporation
• Inventors: Busch-Sorensen, Thomas
• Granted Patent: US 9,509,436 B2
• Time in Patent Office: Days
• US Class Current: 455/1
• CPC Class Codes: G06K 19/07336 Active means, e.g. jamming or scrambling of the electromagnetic field
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 7/10287 the arrangement including a further device in the proximity of the interrogation device, e.g. signal scrambling devices
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/75 for isolation purposes
• CPC Class Codes: H04K 3/86 related to preventing deceptive jamming or unauthorized interrogation or access, e.g. WLAN access or RFID reading record carriers with integrated circuit chips including means for preventing undesired reading or writing from or to record carriers by hindering electromagnetic reading or writing G06K19/07318; arrangements for sensing record carriers including arrangements for protecting the interrogation against piracy attacks G06K7/10257

Abstract

Techniques are disclosed for protecting communication of an NFC-enabled device by generating one or more blocking signals during an NFC data exchange. The blocking signal(s) can include a similar carrier frequency, modulation type, and/or modulation rate an NFC signal, thereby effectively masking the NFC signal. Furthermore, the blocking signal(s) can have a varying amplitude and/or length, which can further mask when an NFC signal is transmitted.

Claims

1. A transmitter for protecting a first near-field communication (NFC) signal transmitted by a mobile device, the transmitter comprising:

a transmit circuit configured to;

generate a first blocking signal having a carrier frequency of the first NFC signal such that the first blocking signal is transmitted while the first NFC signal is transmitted; and

modulate the first blocking signal with a type of modulation of the first NFC signal; and

a first antenna;

communicatively coupled to the transmit circuit so as to radiate the first blocking signal, and

configured to be coupled with the mobile device.

2. The transmitter of claim 1, wherein the transmit circuit is configured to generate a second blocking signal such that the second blocking signal is transmitted while a second NFC signal is transmitted by a device other than the mobile device.

3. The transmitter of claim 1, wherein the transmit circuit is configured to generate the first blocking signal such that the first blocking signal is transmitted while a second NFC signal is transmitted by a device other than the mobile device.

4. The transmitter of claim 1, wherein the transmit circuit is configured to generate the first blocking signal such that the first blocking signal has a varying amplitude.

5. The transmitter of claim 1, wherein the transmit circuit and the first antenna are embedded within an accessory configured to be physically coupled with the mobile device.

6. The transmitter of claim 1, wherein the transmit circuit and the first antenna are embedded within the mobile device.

7. The transmitter of claim 1, further comprising a second antenna configured to be coupled with the mobile device, and configured to transmit the first NFC signal.

8. The transmitter of claim 7, wherein the second antenna is configured to transmit the first NFC signal by modulating a magnetic field.

9. The transmitter of claim 1, further comprising a detection circuit configured to detect the first NFC signal, wherein the detection circuit is coupled to the transmit circuit such that the transmit circuit generates the first blocking signal when the detection circuit detects the first NFC signal.

10. The transmitter of claim 9, wherein the detection circuit is configured to detect a second NFC signal from a device other than the mobile device, wherein the detection circuit is coupled to the transmit circuit such that the transmit circuit generates the a second blocking signal when the detection circuit detects the second NFC signal.

11. The transmitter of claim 1, further comprising a second antenna coupled to the transmit circuit, wherein the transmit circuit is configured to drive the first antenna and the second antenna with the first blocking signal in an alternating fashion.

12. The transmitter of claim 11, wherein the second antenna is disposed perpendicular to the first antenna.

13. The transmitter of claim 1, further comprising a pseudo-random number generator coupled to the transmit circuit.

14. The transmitter of claim 13, wherein the transmit circuit is configured to modulate the first blocking signal using values from the pseudo-random number generator.

15. The transmitter of claim 13, wherein the transmit circuit is configured to vary an amplitude of the first blocking signal using values from the pseudo-random number generator.

16. A method of protecting near-field communication (NFC) signals, the method comprising:

generating a first blocking signal at a carrier frequency of a first NFC signal generated by a mobile device such that the first blocking signal has a varying amplitude;

modulating the first blocking signal with a certain modulation having the same modulation type and modulation rate of the first NFC signal; and

driving an antenna coupled to the mobile device with the modulated first blocking signal while the mobile device transmits the first NFC signal.

17. The method of claim 16, further comprising:

detecting a second NFC signal generated by a device other than the mobile device; and

driving the antenna with a second modulated blocking signal in response to detecting the second NFC signal.

18. The method of claim 16, further comprising driving the antenna the modulated first blocking signal while a second device transmits a second NFC signal.

19. A mobile device comprising:

an NFC antenna;

a signal-blocking antenna; and

a processing unit coupled to the NFC antenna and the signal-blocking antenna, the processing unit configured to perform functions including;

causing the NFC antenna to transmit an NFC signal having a carrier frequency, a modulation rate, and a modulation type;

generating a blocking signal at the carrier frequency of the NFC signal;

modulating the blocking signal with a certain modulation having the same carrier frequency, modulation rate, and modulation type as the NFC signal; and

causing the signal-blocking antenna to transmit the modulated blocking signal while the NFC antenna is transmitting the NFC signal.

20. The mobile device of claim 19, wherein the processing unit is configured to cause the signal-blocking antenna to transmit the modulated blocking signal while the NFC antenna receives one or more NFC signals from another device.