Ultrasonic NFC Transaction Security via Angle Detection

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Solution Overview

Problem

NFC-based secure payment systems face security risks due to the need for additional hardware in mobile devices and potential fraudulent transactions from malicious devices that can mimic payment terminals, especially in environments like train stations where devices can communicate from angular positions.

Innovation Solution

Implementing a device with multiple microphones to detect and calculate the angle of arrival of ultrasonic signals, disregarding signals outside a preset threshold range and performing transactions only when the angle is within the threshold, ensuring secure communication by encrypting data using public-private keys and rejecting communications from devices outside the intended range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If NFC technology uses RFID with additional hardware in mobile phones, then secure payment functionality is enabled, but device complexity and cost increase

Engineering Contradiction:
Improvesecure payment functionalityVSAvoidadditional hardware
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the traditional RFID electromagnetic field-based communication with ultrasonic acoustic wave communication. This substitution eliminates the need for additional NFC hardware in mobile devices, utilizing only the existing microphone and speaker components. The ultrasonic signals carry encoded payment information, enabling secure transactions without increasing device complexity or requiring specialized RFID components.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If NFC devices communicate without angle verification, then communication convenience is maintained, but security against fraudulent transactions deteriorates

Engineering Contradiction:
Improvecommunication convenienceVSAvoidsecurity against fraudulent transactions
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements a feedback mechanism by using an array of microphones to detect the angle of arrival of ultrasonic signals. The system continuously monitors the angular position of the communicating device and provides feedback by accepting or rejecting transactions based on whether the angle falls within a predetermined safe range. This ensures that only devices in authorized positions can complete transactions, preventing fraudulent communications from angular positions while maintaining convenience for legitimate users.

Inventive Principle:
Principle #23Feedback

3Area of stationary object

If ultrasonic signals are transmitted without directional control, then communication coverage is maximized, but security against angular position fraud deteriorates

Engineering Contradiction:
Improvecommunication coverageVSAvoidsecurity against angular position fraud
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent applies local quality by creating directional ultrasonic signal transmission and reception zones. Instead of omnidirectional communication, the system establishes specific angular sectors where communication is permitted. The microphones are arranged to detect signals only from approved angular positions, creating localized secure communication zones while preventing fraud from other directions. This selective angular acceptance maintains security without unnecessarily restricting legitimate communication coverage.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances security in ultrasonic-based NFC transactions by ensuring only devices in direct line of sight can communicate, reducing the risk of fraudulent transactions and maintaining user privacy through directional ultrasonic signals and encryption.

Implementation Method 1

transmitting from a source at least one ultrasonic acoustic signal, encoded with information to the computer; and receiving the at least one signal by said microphone, to be detected by the computer

Methodology Applied
Scientific EffectUltrasonic acoustic signal transmission: Sound

Data Source

PatentEP2966792B1Ultra-sound communication system
Publication Date: 2018.05.16 NXP BV
  • EP2966792B1 patent drawingFigure 1
  • EP2966792B1 patent drawingFigure 2~3
  • EP2966792B1 patent drawingFigure 4

AI summary

A device is disclosed. The device includes a plurality of microphones to receive ultra-sound signals, wherein the ultra-sound signals include an encoded data. The device also includes a microcontroller coupled to the plurality of microphones. The microcontroller is configured to detect the ultra-sound signals through the plurality of microphones. The detection of the ultra-sound signals includes calculating an angle of arrival of the ultra-sound signals at a microphone in the plurality of microphones. The microcontroller is configured to perform a transaction based on the encoded data received via a microphone in the plurality of microphones.