Encryption Technique Using Pseudo and Physical Random Numbers

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Solution Overview

Problem

Conventional mathematical encryption methods, such as stream ciphers, are vulnerable to known plaintext attacks, and quantum cryptography systems require quantum-mechanical properties, limiting their application range and compatibility with various media types.

Innovation Solution

A cryptographic technique using a combination of pseudo random numbers and physical random numbers to generate discrete values for encryption, allowing for channel coding and decryption, with the number of states of pseudo random numbers, physical random numbers, and discrete values configured to provide high encryption strength suitable for diverse media types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quantum cryptography is used to achieve high encryption strength, then encryption strength is improved, but application range is limited due to requirement of quantum-mechanical properties

Engineering Contradiction:
Improveencryption strengthVSAvoidapplication range
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent replaces the quantum-mechanical system with a classical information processing system. Instead of using quantum states and quantum-mechanical properties for encryption, the invention uses classical pseudo-random number generation combined with channel coding to achieve high encryption strength that is applicable to various media including electric memories and electromagnetic wave communication.

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

2Ease of operation

If pseudo random numbers are used for encryption, then ease of operation is improved, but encryption strength deteriorates due to vulnerability to known plaintext attacks

Engineering Contradiction:
Improveease of operationVSAvoidencryption strength
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent creates a composite encryption system that combines pseudo-random number generation with channel coding techniques. This composite approach maintains the ease of operation of pseudo-random methods while adding the cryptographic strength of channel coding, making the system resistant to known plaintext attacks.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent transitions from one-dimensional pseudo-random number sequences to a multi-dimensional encryption space by incorporating channel coding dimensions. This adds structural complexity and redundancy that prevents attackers from recovering the encryption key even when obtaining plaintext-ciphertext pairs.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP1780934B1Quantum cryptography encryption, decryption method apparatus and systems
Publication Date: 2017.03.22 FUJITSU LTD
  • EP1780934B1 patent drawingFigure 1
  • EP1780934B1 patent drawingFigure 2
  • EP1780934B1 patent drawingFigure 3

AI summary

A quantum encryption technique including a step for modulating one-bit input data into a coded signal by associating it with a discrete value of at least two bits determined by pseudo random numbers and physical random numbers and a step for channel-coding and 10 outputting the coded signal, wherein 1) the coded signal can be demodulated into the input data by the pseudo random number, 2) the number of sets of input data, pseudo random number, and physical random number corresponding to a particular discrete value is equal for two values of the 15 input data, and 3) the number of sets of pseudo random number and physical random number corresponding to respective values of the input data and respective values of the discrete value is equally associated also with any set of them.