Optical Network Traffic Segmentation for Tapping Security

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Solution Overview

Problem

Fibre tapping attacks in optical networks are difficult to detect and prevent, as they introduce minimal loss in optical signals, making current security methods either expensive or unreliable, and existing solutions fail to prevent access to encrypted data.

Innovation Solution

A method of transmitting communications traffic in an optical communication network by dividing it into portions and switching them across spatially separate optical paths, ensuring that no single portion can be reconstructed without others, which can be used in conjunction with existing security methods without requiring radical changes in network equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If fibre tapping is used to intercept optical signals, then access to communications traffic is gained, but detection of the attack becomes extremely difficult

Engineering Contradiction:
Improvesecurity vulnerability to tappingVSAvoiddetection of tapping attack
Core Design Contradiction:
Object-affected harmful factorsVSDifficulty of detecting and measuring

Solution Approach 1:

The optical signal is divided into multiple segments that are transmitted through different spatial paths. Each segment alone is insufficient to reconstruct the original information, making tapping ineffective unless all segments are intercepted simultaneously, which is detectable due to the coordinated switching mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches the optical signal between multiple spatial paths in real-time. This dynamic path switching prevents static tapping devices from capturing continuous traffic, as the signal location changes unpredictably between segments.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If encryption is used to protect communications traffic, then security against interception is improved, but encryption can ultimately be broken

Engineering Contradiction:
Improvesecurity protectionVSAvoidsecurity reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

Instead of relying solely on encryption, the system segments the optical signal into multiple physical paths. Even if encryption is broken, the attacker cannot reconstruct the original signal without capturing all segments simultaneously, adding a physical layer security mechanism that complements cryptographic protection.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If physical protection of optical fibre cables is implemented, then security against tapping is improved, but the cost and complexity increases significantly

Engineering Contradiction:
Improvephysical securityVSAvoidprotection system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Rather than implementing static physical protection measures along entire fibre routes, the system uses dynamic optical switching to move signal segments between paths. This reduces the need for extensive physical security infrastructure while maintaining security through active path management.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The optical switching infrastructure serves dual purposes: normal traffic routing and security protection through path diversification. The same switching mechanisms used for network management and load balancing also provide the security function of distributing signal segments across multiple paths.

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

4Difficulty of detecting and measuring

If network monitoring systems are deployed to detect fibre tapping, then detection capability is improved, but the systems are expensive and prone to false alarms

Engineering Contradiction:
Improvetapping detection capabilityVSAvoidmonitoring infrastructure cost
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The system proactively prevents tapping effectiveness by segmenting and distributing the signal before transmission, rather than relying on reactive monitoring to detect attacks. This preliminary security measure reduces the need for expensive monitoring systems while maintaining detection capability through the inherent structure of the transmitted signal.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3058686B1Transmitting communications traffic across an optical communication network
Publication Date: 2020.04.29 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3058686B1 patent drawingFigure 1
  • EP3058686B1 patent drawingFigure 2
  • EP3058686B1 patent drawingFigure 3

AI summary

A method (10) of transmitting communications traffic in an optical communication network comprising a plurality of nodes, the method comprising, at a source node: receiving communications traffic to be transmitted across the optical communication network to a target node (12); obtaining a path sequence defining an order in which a plurality of optical paths from the source node to the target node across the optical communication network are to be used, at least part of each optical path being spatially separate from each other optical path (14); and transmitting the communications traffic as a series of traffic portions, each traffic portion being transmitted for a respective preselected transmission period on a respective optical path according to the path sequence (16, 18, 20, 22, 24, 26).