Programmable Ultrasonic Transceiver for Secure Key Exchange

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Solution Overview

Problem

Current ultrasonic transceiver systems require separate hardware designs for different applications, and existing key generation and exchange processes are vulnerable to randomness limitations and man-in-the-middle attacks, making them inefficient and insecure.

Innovation Solution

A programmable ultrasonic transceiver system with a transmitter block, receiver block, state machine, computing unit, and program memory that can be reprogrammed for various functions, incorporating a public key encryption submodule using recorded ultrasonic noise to generate random keys and secure key exchange over an ultrasonic medium.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If separate hardware systems are designed for different applications, then application-specific performance is optimized, but device complexity and development time increase

Engineering Contradiction:
Improveapplication versatilityVSAvoidhardware complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a single ultrasonic transceiver hardware platform that can perform multiple applications including proximity detection, rangefinding, triangulation, data transmission, and public key cryptography. This is achieved through a reconfigurable architecture where the same physical hardware (transducer, transmitter, receiver, processor) can be programmed to execute different protocols and functions, eliminating the need for separate dedicated hardware systems for each application.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system employs dynamic reconfigurability through programmable control logic and software-defined protocols. The transceiver can dynamically switch between different operational modes and applications by loading different protocol implementations and configuration parameters, allowing the hardware to adapt its behavior based on the required application without physical reconfiguration.

Inventive Principle:
Principle #15Dynamics

2Reliability

If conventional key generation processes are used, then key exchange is simplified, but security vulnerability increases due to limited randomness

Engineering Contradiction:
Improvekey generation securityVSAvoidkey generation process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses ultrasonic noise as an intermediary medium to generate random keys. The system captures ambient ultrasonic noise through the ultrasonic transceiver, processes this noise to extract random bits, and uses these bits for key generation. This intermediary approach leverages the randomness inherent in environmental ultrasonic signals to create secure keys without relying on conventional pseudo-random number generators with limited entropy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If public keys are exchanged over traditional networks, then communication establishment is straightforward, but susceptibility to man-in-the-middle attacks increases

Engineering Contradiction:
Improvekey exchange securityVSAvoidkey exchange complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces traditional network-based key exchange mechanisms with ultrasonic wave-based key exchange. Instead of transmitting public keys over vulnerable digital networks, the system encodes public keys into ultrasonic signals that are transmitted through the air using the ultrasonic transceiver. This substitution leverages the physical properties of ultrasonic waves (directionality, attenuation, requiring line-of-sight) to create a more secure key exchange channel that is inherently resistant to eavesdropping and man-in-the-middle attacks.

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

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

Enables multiple applications with a single hardware system by updating firmware remotely and provides secure key exchange resistant to interception, ensuring truly random keys and preventing man-in-the-middle attacks.

Implementation Method 1

Ultrasonic transducers can be used for a variety of applications

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a transmitter block containing circuitry configured to drive an ultrasound transducer

Methodology Applied
Scientific EffectElectroacoustic conversion:

Implementation Method 3

receiver block containing circuitry configured to receive signals from the ultrasound transducer and convert the signals into digital data

Methodology Applied
Scientific EffectAcoustoelectric conversion:

Data Source

PatentEP3350589B1Programmable ultrasonic transceiver
Publication Date: 2024.08.21 INVENSENSE INC
  • EP3350589B1 patent drawingFigure 1A
  • EP3350589B1 patent drawingFigure 1B
  • EP3350589B1 patent drawingFigure 2~3

AI summary

An ultrasonic transceiver system includes a transmitter block, a receiver block, a state machine, a computer unit. The transmitter block contains circuitry configured to drive an ultrasound transducer. The receiver block contains circuitry configured to receive signals from the ultrasound transducer and convert the signals into digital data. The state machine is coupled to the transmitter and receiver blocks and contains circuitry configured to act as a controller for those blocks. The computing unit is coupled to the transmitter block, the receiver block, and the state machine and is configured to drive the transmitter block and process data received from the receiver block by executing instructions of a program. The program memory is coupled to the computing unit and is configured to store the program. The computing unit is configured to be reprogrammed with one or more additional programs stored in the program memory.