QKD Key Management Node Encrypted Tunnel Relay

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In large-scale Quantum Key Distribution (QKD) networks, the processing load and delay for encryption key relay increase, making it difficult to provide encryption keys in a timely manner due to the need for multiple key relays, which affects scalability.

Innovation Solution

Implementing an encrypted tunnel using a middle key (M key) shared between key management nodes to reduce the number of nodes involved in encryption/decryption, thereby simplifying the key relay process and distributing the processing load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the scale of QKD network increases to provide more encryption keys, then the coverage and functionality of the network is improved, but the processing load and delay for key relay increases

Engineering Contradiction:
Improvenetwork coverageVSAvoidkey relay efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent introduces a key management node as an intermediary component in the QKD network. This node establishes encrypted tunnel communication with other key management nodes and relays encryption keys through these tunnels, thereby mediating the key distribution process and reducing the processing burden on individual nodes while maintaining network scalability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the key relay process by establishing dedicated encrypted tunnels between key management nodes. Instead of having every node directly participate in every key relay operation, the system divides the network into segments connected through these pre-established tunnels, reducing the number of nodes involved in each specific key relay operation.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If multiple key relays are performed to provide encryption keys between distant nodes, then the network connectivity is improved, but the processing delay increases

Engineering Contradiction:
Improvenetwork connectivityVSAvoidkey relay delay
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements preliminary action by pre-establishing encrypted tunnel communication between key management nodes before actual key relay operations. These tunnels are set up in advance with shared encryption keys, so when key relay is needed, the communication path is already prepared, significantly reducing the processing delay.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If the number of nodes involved in encryption/decryption is reduced to decrease processing load, then the key relay efficiency is improved, but the network scalability may be affected

Engineering Contradiction:
Improvekey relay efficiencyVSAvoidnetwork scalability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The key management node is designed with universal functionality to establish encrypted tunnels with any other key management node in the network. This multi-functional capability allows the system to reduce the number of nodes involved in each specific key relay operation while maintaining the ability to scale to any network size, as the same node can communicate with multiple partners through standardized tunnel protocols.

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

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 reduces the processing load and delay of key relays, ensures timely key delivery, and improves efficiency by establishing an encrypted tunnel between key management nodes that frequently communicate, thus minimizing congestion and maintaining key security.

Implementation Method 1

Quantum key distribution (QKD) is a technology for securely sharing an encryption key between a QKD device that continuously transmits a single photon and a QKD device that receives a single photon, where the QKD devices are connected by an optical fiber link. An encryption key shared by the QKD is guaranteed not to be eavesdropped based on the principle of quantum mechanics.

Methodology Applied
Scientific EffectQuantum key distribution:

Data Source

PatentEP4529079A1Information processing device, QKD network system, information processing method, and computer program product
Publication Date: 2025.03.26 KK TOSHIBA
  • EP4529079A1 patent drawingFigure 1A
  • EP4529079A1 patent drawingFigure 1B
  • EP4529079A1 patent drawingFigure 2A

AI summary

According to one arrangement, an information processing device (1) includes a processing unit (11) configured to establish encrypted tunnel communication with a second node by using a second encryption key subjected to encrypted relay transmission to the second node by a first encryption key shared, by quantum key distribution, with a plurality of first nodes adjacent to each other. The second node is one of the plurality of first nodes. The processing unit (11) is configured to cause a network interface (IF) unit (12) to transfer a third encryption key to the second node by the encrypted tunnel communication.