Quantum User Authentication with Pre-Shared Basis Selection

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Solution Overview

Problem

Existing quantum communication systems face challenges in user authentication due to mismatched bases between transmitting and receiving ends, leading to information loss and the need for separate error correction processes.

Innovation Solution

A method and device for user authentication in quantum communication systems using a pre-shared key to encode authentication messages, determining bit elements based on the pre-shared key, and measuring authentication quantum information to authenticate without separate error correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If basis selection is performed randomly in quantum communication authentication, then authentication can be carried out, but information loss occurs due to basis mismatch between transmitting and receiving ends

Engineering Contradiction:
Improveauthentication reliabilityVSAvoidauthentication information loss
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by pre-sharing a key between the transmitting end and receiving end before authentication. This pre-shared key is used to determine the basis for encoding and measuring authentication quantum information, ensuring both parties use the same basis without random selection, thereby eliminating basis mismatch and information loss.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If separate error correction process is added to handle channel errors in authentication, then authentication accuracy improves, but system complexity and processing time increase

Engineering Contradiction:
Improveauthentication accuracyVSAvoidauthentication process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the authentication process with error handling by using quantum mechanical principles where the authentication outcome naturally reflects channel quality. The authentication result itself serves as an indicator of channel errors, eliminating the need for separate error correction processes while maintaining authentication accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The authentication quantum information itself provides information about channel conditions through its measurement results. The system uses the quantum information's inherent properties to self-assess authentication success and channel quality without requiring external error correction mechanisms.

Inventive Principle:
Principle #25Self-service

3Loss of information

If pre-shared key is used for basis determination, then information loss due to basis mismatch is reduced, but key management complexity increases

Engineering Contradiction:
Improveauthentication information lossVSAvoidkey management complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The pre-shared key serves multiple functions: it determines the basis for encoding authentication quantum information, enables the receiving end to select the correct measurement basis, and provides a reference for verifying authentication results. This multi-functionality reduces the need for separate key management protocols.

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

Data Source

PatentEP4597918A1Method for carrying out user authentication by applying pre-shared key to basis selection in quantum communication system, and device therefor
Publication Date: 2025.08.06 LG ELECTRONICS INC
  • EP4597918A1 patent drawingFigure 1
  • EP4597918A1 patent drawingFigure 2
  • EP4597918A1 patent drawingFigure 3

AI summary

The present disclosure provides a method for carrying out user authentication in a quantum communication system. More specifically, the method comprises the steps of: on the basis of a pre-shared key, generating authentication quantum information by encoding an authentication message for user authentication, wherein a basis, for encoding each bit element constituting the authentication message, the respective bit elements corresponding to the respective positions of bit elements constituting the pre-shared key, is determined on the basis of respective bit values of the bit elements constituting the pre-shared key; transmitting the authentication quantum information to a receiving end via a quantum channel; receiving, from the receiving end, authentication quantum information measurement information related to a value derived by means of the receiving end measuring the authentication quantum information; and carrying out user authentication with the receiving end on the basis of the authentication quantum information measurement information.