NEAR-FIELD COMMUNICATION (NFC) SYSTEM AND METHOD FOR PRIVATE NEAR-FIELD COMMUNICATION

• US 20130185213A1
• Filed: 01/17/2012
• Published: 07/18/2013
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Raytheon BBN Technologies Corp. (Rtx Corporation)
• Original Assignee: Raytheon BBN Technologies Corp. (Rtx Corporation)
• Inventors: Insanic, Edin
• Granted Patent: US 10,037,522 B2
• Time in Patent Office: Days
• US Class Current: 705/73
• CPC Class Codes: G06Q 20/32 using wireless devices
• CPC Class Codes: H04B 5/72 for local intradevice communication

Abstract

Embodiments of a near-field communication (NFC) system and method for private near-field communication are generally described herein. In some embodiments, a resonance-coupled channel is masked with a random channel-masking signal. The channel-masking signal may be scaled based on near-field channel conditions. Signals received through the channel may be unmasked with the scaled channel-masking signal to determine data that may have been conveyed by an NFC transmitting device by affecting the impedance of the resonance-coupled channel. In some embodiments, a reference signal may be scrambled with a mask to generate the channel-masking signal. The mask may include at least one of a random symbol mask, an amplitude mask and a phase mask. For additional privacy, the mask may include a random symbol mask and at least one of an amplitude mask and a phase mask.

Claims

1. A near-field communication (NFC) system comprising an NFC receiver to receive data privately from an NFC transmitter through a resonance-coupled channel, the NFC receiver comprising:

a channel-masking signal generator to scramble a reference signal and generate a channel-masking signal for application to the resonance-coupled channel;

a scaling element to scale the channel-masking signal based, at least in part, on near-field channel conditions; and

unmasking circuitry to combine the scaled channel-masking signal with resonance-coupled signals received through the resonance-coupled channel to generate binary data as an output comprising unmasked bits.

2. The NFC system of claim 1 wherein the NFC transmitter comprises an impedance-switching element to affect an impedance of the resonance-coupled channel based on binary data to be conveyed to the NFC receiver.

3. The NFC system of claim 2 wherein the impedance-switching element is to affect the impedance of the resonance-coupled channel by switching between a first impedance and a second impedance based on the binary data that is to be conveyed to the NFC receiver.

4. The NFC system of claim 2 wherein the NFC receiver further comprises a reactive element to affect the resonance-coupled channel with the channel-masking signal and receive the resonance-coupled signals, and

wherein the NFC transmitter further comprises a reactive element to modulate die resonance-coupled channel based on a switched impedance signal provided by the impedance-switching element.

5. The NFC system of claim 2 wherein the NFC receiver further comprises a first antenna to provide the resonance-coupled channel affected with the channel-masking signal and receive the resonance-coupled signals, and

wherein the NFC transmitter further comprises a second antenna to modulate the resonance-coupled channel based on a switched impedance signal provided by the impedance-switching element.

6. The NFC system of claim 1 wherein the NFC receiver is part of an NFC reader and the NFC transmitter is part, of an NFC tag.

7. The NFC system of claim 1 wherein the scaling element is to scale the channel-masking signal in both amplitude and phase based on parameters determined during a calibration process.

8. The NFC system of claim 1 wherein the channel-masking signal generator is to scramble the reference signal by modulating the reference signal with a mask to generate the channel-masking signal, and

wherein the mask comprises a random symbol mask, and at least one of an amplitude mask and a phase mask.

9. The NFC system of claim 8 wherein the symbol mask, the amplitude mask and the phase mask comprise non-correlated random sequences.

10. The NFC system of claim 1 wherein the NFC receiver is to receive data privately from the NFC transmitter through the resonance-coupled channel when the NFC receiver is positioned within a near field of the NFC transmitter, the near field being less than ¼

wavelength of an operating frequency.

11. The NFC system of claim 10 wherein when the NFC receiver and the NFC transmitter are configured to perform a calibration process when operating in the near field, the calibration process to determine parameters for use by the scaling element.

12. A method for private communication through a resonance-coupled channel, the method comprising:

masking the resonance-coupled channel with a random channel-masking signal;

scaling the channel-masking signal based on near-field channel conditions; and

unmasking signals received through the resonance-coupled channel with the scaled channel-masking signal to determine data, the data conveyed by a transmitting device by affecting an impedance of the resonance-coupled channel.

13. The method of claim 12 wherein the transmitting device is to affect the impedance of the resonance-coupled channel based on binary data to be conveyed to a receiving device,

wherein masking comprises scrambling a reference signal by modulating the reference signal with a mask to generate the random channel-masking signal, and

wherein the mask comprises one of a random symbol mask, an amplitude mask and a phase mask.

14. The method of claim 13 wherein masking includes affecting the resonance-coupled channel with the channel-masking signal using a first reactive element,

wherein the method includes receiving the signals through the resonance-coupled channel with the first reactive element,

wherein a second reactive element is used by die transmitting device to modulate the resonance-coupled channel based on a switched impedance signal.

15. The method of claim 14 wherein the receiving device is to receive data privately from the transmitting device through the resonance-coupled channel when the receiving device is positioned within a near field of the transmitting device, the near field being less than ¼

wavelength of an operating frequency.

16. A method for secure key exchange between devices using near-field communication, the method comprising:

masking, by a first near-field communication (NFC) device, a resonance-coupled channel with a random channel-masking signal;

scaling, by the first NFC device, the channel-masking signal based on near-field channel conditions; and

unmasking signals received through the resonance-coupled channel by the first NFC device with the scaled channel-masking signal to determine a key conveyed to a second NFC device by affecting an impedance of the resonance-coupled channel based on binary values of the key.

17. A system for secure financial transactions between near-field communication (NFC) devices, the system comprising an NFC transmitter and an NFC receiver to receive financial data from the NFC transmitter through a resonance-coupled channel when positioned within a near-field of the NFC transmitter, the NFC receiver comprising:

a channel-masking signal generator to scramble a reference signal and generate a channel-masking signal for modulating the resonance-coupled channel;

a scaling element to scale the channel-masking signal based on near-field channel conditions; and

unmasking circuitry to combine the scaled channel-masking signal with signals received through the resonance-coupled channel to generate binary data as an output comprising unmasked bits,

wherein the NFC transmitter is to affect an impedance of the resonance-coupled channel based on values of the financial data to be conveyed to the NFC receiver.

18. The system of claim 17 wherein the NFC transmitter is provided with a mobile communication device (smart phone) and wherein the NFC receiver is provided within a point-of-sale (POS) terminal.