SPAD-Based Optical Communication for Secure Data Transfer

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Solution Overview

Problem

Existing communication systems, particularly RF-based ones, face security issues due to the potential for interception and monitoring, as they are often omnidirectional and vulnerable to 'man-in-the-middle' attacks, whereas optical systems like IrDA are not widely implemented due to size, cost, and low data rate limitations.

Innovation Solution

A modified SPAD-based light detecting and ranging module that uses a narrow beam of light for secure communication between devices, employing a time-of-flight SPAD module with a VCSEL to transmit and receive data securely, enabling cryptographic key exchange and secure data transfer while minimizing interception risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If RF-based communication systems are used, then communication coverage and connectivity are improved, but security against interception and monitoring deteriorates

Engineering Contradiction:
Improvecommunication coverageVSAvoidsecurity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces RF-based electromagnetic communication with optical communication using light beams. This substitution fundamentally changes the communication medium from radio waves to light, enabling secure line-of-sight communication that is inherently more resistant to interception while maintaining communication functionality.

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

Solution Approach 2:

The patent employs asymmetric communication geometry where the transmitter emits a narrow, directed light beam to a specific receiver, creating an asymmetric communication path that is difficult to intercept. This directional asymmetry contrasts with omnidirectional RF transmission and provides inherent security through physical orientation requirements.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If optical communication systems like IrDA are implemented, then security is improved, but device size, cost, and data rate limitations worsen

Engineering Contradiction:
ImprovesecurityVSAvoiddevice size and cost
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the optical communication system bidirectional, allowing both devices to function as transmitters and receivers. This multi-functionality enables mutual authentication and cryptographic key exchange, enhancing security while maintaining compatibility with existing mobile device form factors and reducing overall system complexity.

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

Solution Approach 2:

The patent combines optical communication capabilities with existing mobile device components, integrating the optical transmitter and receiver into the device housing. This merging approach reduces device size and cost by sharing structural elements and control systems rather than adding completely separate communication subsystems.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If optical communication systems like IrDA are implemented, then security is improved, but data transmission rate deteriorates

Engineering Contradiction:
ImprovesecurityVSAvoiddata transmission rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs advanced modulation techniques and adjusts optical communication parameters such as modulation frequency, pulse width, and detection sensitivity to achieve high data transmission rates. By optimizing these parameters, the system overcomes the traditional low data rate limitation of optical communication while maintaining secure line-of-sight transmission.

Inventive Principle:
Principle #35Parameter changes

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

The solution provides a secure, high-data-rate communication method that prevents unauthorized interception and ensures device authentication, enhancing communication security by using narrow beams of light, which are less susceptible to eavesdropping and 'man-in-the-middle' attacks, and integrates with existing mobile devices without additional components.

Implementation Method 1

A modified SPAD-based light detecting and ranging module that uses a narrow beam of light for secure communication between devices, employing a time-of-flight SPAD module with a VCSEL to transmit and receive data securely

Methodology Applied
Scientific EffectLight emission and modulation: Laser

Implementation Method 2

A first time-of-flight camera has an illumination unit configured to transmit information to a second time-of-flight camera by modulating a light signal to be emitted in accordance with an information bearing signal. The second time-of-flight camera has a time-of-flight sensor configured to detect the information bearing signal included in the emitted light signal of the first time of flight camera

Methodology Applied
Scientific EffectPhoton detection: Photoelectric Effect

Implementation Method 3

A modified SPAD-based light detecting and ranging module that uses a narrow beam of light for secure communication between devices, employing a time-of-flight SPAD module

Methodology Applied
Scientific EffectTime of flight measurement: Time of Flight

Data Source

PatentEP3185039B1Apparatus and method for range detection and communication
Publication Date: 2021.09.08 STMICROELECTRONICS (RES & DEV) LTD
  • EP3185039B1 patent drawingFigure 1
  • EP3185039B1 patent drawingFigure 2
  • EP3185039B1 patent drawingFigure 3a

AI summary

An apparatus comprising: at least one ToF SPAD based range detecting module configured to generate at least one distance determination between the apparatus and an object within a module field of view, wherein the module is further configured to communicate with at least one further apparatus further comprising a ToF SPAD based range detecting module.