Quantum Probe Signal Distribution for Optical Fiber Eavesdropping Detection

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Solution Overview

Problem

Current eavesdropping detection methods in optical fiber communication systems are limited to detecting interception on the Quantum Channel and cannot effectively detect eavesdropping attempts on the Service Channel or Data Channel, which are critical for secure data transmission.

Innovation Solution

The system generates and distributes quantum probe signals and data signals randomly and alternately across multiple channels, using a Controlling Unit to synchronize and authenticate these signals, allowing for the detection of eavesdropping attempts on any channel by employing quantum key distribution units and commutating devices that switch channels based on a shared key, thereby triggering an alarm or rerouting data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If attenuation monitoring is used to detect eavesdropping, then detection capability is provided, but false positive results occur and pre-existing interception devices cannot be detected

Engineering Contradiction:
Improveeavesdropping detection capabilityVSAvoiddetection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary actions by randomly distributing quantum probe signals across multiple channels before eavesdropping can occur. This proactive approach allows the system to detect pre-existing interception devices that traditional attenuation monitoring would miss, as the quantum signals are already in place to reveal any tampering.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Quantum probe signals serve as intermediaries between the transmitter and receiver. These probe signals mediate the detection process by interacting with the communication channel and revealing eavesdropping attempts through quantum state changes, providing more accurate detection than direct attenuation monitoring.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If quantum probe signals are distributed randomly across multiple channels, then eavesdropping detection on any channel is enabled, but system complexity increases

Engineering Contradiction:
Improveeavesdropping detection coverageVSAvoidsignal distribution system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The quantum probe signal distribution system performs multiple functions: it detects eavesdropping on any channel, maintains communication security, and provides channel monitoring. By making the probe distribution system universal and multi-functional, the patent reduces overall system complexity while improving detection coverage across all channels.

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

Solution Approach 2:

The system dynamically distributes quantum probe signals across multiple channels based on random selection rather than fixed assignment. This dynamic approach allows the system to adapt to different communication scenarios and detect eavesdropping on any channel without requiring a static, overly complex distribution architecture.

Inventive Principle:
Principle #15Dynamics

3Loss of information

If encryption is used to protect optical signals, then information security is improved, but encrypted data can still be deciphered through software or hardware means

Engineering Contradiction:
Improveinformation securityVSAvoidprotection against deciphering
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent converts the harmful effect of potential eavesdropping into a beneficial detection mechanism. By using quantum probe signals that are sensitive to any interception attempt, the system transforms the risk of encryption being broken into an opportunity to detect and alert about eavesdropping attempts, providing an additional layer of security beyond encryption alone.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This approach enables the detection of eavesdropping attempts on any channel between the emitter and receiver, ensuring secure data transmission by preventing eavesdroppers from anticipating which channels carry quantum or data signals, thus enhancing the security of optical fiber communication systems.

Implementation Method 1

exchanging probe signals on a channel between quantum key distribution units

Methodology Applied
Scientific EffectOptical signal transmission: Optical Fibre

Data Source

PatentEP3094038B1Apparatus and method for providing eavesdropping detection of an optical fiber communication
Publication Date: 2019.08.07 ID QUANTIQUE SA
  • EP3094038B1 patent drawingFigure 1
  • EP3094038B1 patent drawingFigure 2a
  • EP3094038B1 patent drawingFigure 2b

AI summary

A method for providing eavesdropping detection of an optic fiber communication between two users comprises the steps of exchanging both data and probe signals through at least two channels (400, 500) between the users, exchanging probe signals (143) on one channel (500 or 400) between quantum probe signal terminals, extracting a key for authentication from the probe signals, exchanging data signals (142) between transmission units on another channel (400 or 500). A first portion of the key generated by the quantum probe signal terminals is used to authenticate the terminals, wherein a second portion of the key is dedicated to define commutation occurrences of commutation devices adapted to commutate the use of the channels (400, 500) for data (142) and probe (143) signals, thus detecting an eavesdropping event (300) which triggers an alarm (750). A further portion of the key can be used to encrypt said messages.