Dynamic Block Size Adjustment for Quantum Key Generation

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Solution Overview

Problem

Conventional quantum key distribution (QKD) systems face challenges in increasing generation speed while maintaining security, particularly due to limitations in resource allocation which lead to reduced cryptographic key lengths and increased estimation errors caused by finite-size effects and environmental fluctuations.

Innovation Solution

A key generation device and method that dynamically adjusts the block size for processing units and hash matrix sizes based on real-time feedback and statistical data to optimize key length calculation and hash operations, ensuring efficient cryptographic key generation under limited resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional QKD techniques are used with fixed resource allocation, then security is maintained, but generation speed cannot be increased

Engineering Contradiction:
Improvekey generation speedVSAvoidkey security
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic resource allocation where the block size for privacy amplification is adjusted in real-time based on observed error rates and security requirements. This allows the system to optimize key generation speed by processing larger blocks when conditions permit, while maintaining security by reducing block size when error rates indicate potential threats, thus resolving the contradiction between productivity and reliability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the parameter of block size dynamically based on observed conditions. By adjusting this parameter according to error rates and security requirements, the system can achieve higher generation speeds when conditions are favorable while maintaining security standards, thereby resolving the contradiction between key generation speed and security

Inventive Principle:
Principle #35Parameter changes

2Productivity

If larger block sizes are used for processing, then processing efficiency increases, but estimation errors due to finite-size effects increase

Engineering Contradiction:
Improveprocessing efficiencyVSAvoiderror rate estimation accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent employs dynamic adjustment of block size based on real-time error rate observations. When error rates are low and stable, larger blocks are used to improve processing efficiency. When error rates increase or show variability, the system reduces block size to maintain accurate estimation, thus dynamically balancing productivity and measurement precision

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from observed error rates to adjust block size. By continuously monitoring error rates and using this information to modify processing parameters, the system optimizes the trade-off between processing efficiency and estimation accuracy, resolving the contradiction between these two parameters

Inventive Principle:
Principle #23Feedback

3Productivity

If resource allocation is increased to improve key generation speed, then productivity increases, but the system becomes less adaptable to environmental fluctuations

Engineering Contradiction:
Improvekey generation speedVSAvoidadaptability to environmental changes
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic resource allocation where computational resources are adjusted in real-time based on observed conditions. This allows the system to allocate more resources for high-speed processing when environmental conditions are stable, while automatically reducing resource allocation when fluctuations are detected, thus maintaining both productivity and adaptability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes resource allocation parameters dynamically based on environmental conditions. By adjusting parameters such as block size and processing intensity according to observed error rates and channel conditions, the system achieves high productivity when possible while maintaining adaptability to environmental fluctuations

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3627757B1Key generation device, key generation method, and computer readable medium
Publication Date: 2022.11.02 KK TOSHIBA
  • EP3627757B1 patent drawingFigure 1
  • EP3627757B1 patent drawingFigure 2
  • EP3627757B1 patent drawingFigure 3

AI summary

According to an arrangement, an information processor includes a calculating unit, a determining unit, and a generating unit. The calculating unit is configured to calculate a key length. The determining unit is configured to determine a block size corresponding to a unit of processing in key generation and an outputtable size indicating the size of a key outputtable by the key generation. The generating unit is configured to generate a key having the key length by a hash operation using a matrix having a size determined by the block size and the outputtable size.