Biometric Key Generation via Error Correction and Secret Amplification

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Solution Overview

Problem

Biometric-based communication link security is challenging due to variability in biometric data acquisition and the assumption that biometric data remains secret, making it vulnerable to passive attacks.

Innovation Solution

A method involving biometric data processing through an advantage distillation phase, followed by information reconciliation and secret amplification, ensures a secure communication link by generating a common key between a user and an entity, even if an attacker has biometric data, by introducing errors and using error correction protocols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a key is calculated by applying mathematical algorithms to a user's biometric data, then the key can be used to secure a communication link, but the key will vary between successive captures due to biometric data variability

Engineering Contradiction:
Improvecommunication link securityVSAvoidbiometric data consistency
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary actions by capturing biometric data multiple times before generating the final key. It stores multiple biometric captures and uses error correction codes to handle variability, ensuring that the key remains consistent despite variations in individual biometric measurements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies error correction codes beforehand to cushion against the variability in biometric data. These codes allow the system to tolerate certain variations in biometric measurements while still generating a consistent and reliable key for secure communication.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Ease of manufacture

If a user's key is completely determined from their biometrics, then the key generation process is simple, but an attacker with biometric data can obtain the key and access the communication link

Engineering Contradiction:
Improvekey generation processVSAvoidvulnerability to passive attacks
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary mechanism using error correction codes and multiple biometric captures as a buffer between the raw biometric data and the final key. This intermediary layer prevents direct derivation of the key from any single biometric capture, including those obtained by attackers, while maintaining the simplicity of the overall key generation process.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If multiple biometric captures are performed to improve key consistency, then the key reliability improves, but the complexity of the key generation process increases

Engineering Contradiction:
Improvekey consistencyVSAvoidbiometric data processing
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs multiple biometric captures and error correction processing as preliminary actions before key generation. By preparing and storing multiple captures in advance and using error correction codes, the system achieves consistent keys without requiring complex real-time processing during the actual key generation phase.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1897267B1Method for providing a secured communication between a user and an entity
Publication Date: 2019.11.06 IDEMIA IDENTITY & SECURITY FRANCE SAS
  • EP1897267B1 patent drawingFigure 1~2
  • EP1897267B1 patent drawingFigure 3~5
  • EP1897267B1 patent drawingFigure 6~7

AI summary

The invention relates to a method for providing a secured communication between a user (1;7) and an entity (4;10b) containing a first set of biometric data (Y0) relating to the user. According to the invention, a second set of biometric data (X0) relating to the user is obtained. An error correction protocol is applied to the first set of biometric data and to the second set of biometric data in such a way that the resulting data is identical to a pre-determined level of probability. A secret amplification phase is implemented, in which a hashing function (G) is applied to the resulting data in order to obtain a key (G(Y2*),G(X2*)) which is common to the user and the entity.