Biometric Identification Bias Evaluation Method

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Solution Overview

Problem

Biometric identification functions for unidentified latent prints in UL databases face issues with high false rejection and acceptance rates, leading to biased results and excessive human examiner workload due to over-learning and misrepresentation during CNN training, particularly in the context of latent print variability and background confusion.

Innovation Solution

A method to evaluate and minimize the bias of biometric identification functions by calculating a bias score based on false match pairs, which involves determining the number of false matches for candidate and reference prints and using these scores to optimize the identification function, thereby reducing the Doddington risk and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If biometric identification functions are optimized using CNN networks with machine learning, then matching performance improves, but false acceptances and false rejections increase due to over-learning and misrepresentation in training databases

Engineering Contradiction:
Improvematching performanceVSAvoidfalse acceptance rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by evaluating bias before deploying the biometric identification function in production. The bias evaluation process uses training databases to calculate bias scores that predict potential false acceptances, allowing optimization of the identification function before it is used for actual identification tasks. This preliminary evaluation prevents the system from proceeding with biased models that would cause excessive false acceptances.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by using bias evaluation results to iteratively improve the biometric identification function. The bias score calculated from false match analysis provides feedback about the model's tendencies, which is then used to adjust training parameters, select better training databases, or modify the identification algorithm to reduce bias and false acceptances in subsequent iterations.

Inventive Principle:
Principle #23Feedback

2Reliability

If the biometric identification function returns more potential candidates to human examiners, then false acceptances are reduced, but human examiner workload increases excessively

Engineering Contradiction:
Improvefalse acceptance rateVSAvoidexaminer workload
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies partial action by having the biometric identification function return only a moderate number of potential candidates to human examiners, rather than all possible matches or none at all. The bias evaluation helps determine the optimal threshold for returning candidates, balancing the need to reduce false acceptances with the practical constraint of examiner workload and available time.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If biometric identification functions are trained on latent print databases, then identification capability improves, but bias increases due to variability and background confusion in latent prints

Engineering Contradiction:
Improveidentification capabilityVSAvoidbias score
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent converts the harmful effect of latent print variability and background confusion into a benefit by using these challenging examples in bias evaluation. The bias evaluation process specifically tests the identification function against latent prints with various degradation patterns, turning the previously harmful variability into a useful diagnostic tool that reveals bias and guides optimization to improve robustness.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS11816879B2Bias evaluation of a biometric identification function
Publication Date: 2023.11.14 IDEMIA PUBLIC SECURITY FRANCE
  • US11816879B2 patent drawing
  • US11816879B2 patent drawing
  • US11816879B2 patent drawing

AI summary

An evaluation method of a biometric identification function implemented from a candidate biometric data set and a reference biometric data set, the biometric identification function, applied to a candidate biometric data item and a reference biometric data item, returning a match, the method comprising steps of:obtaining pairs of false matches, each pair comprising a candidate biometric data item and a reference biometric data item not associated with a same known individual;determining, for each candidate biometric data item in a pair, a first number associated with said item and equal to the number of pairs of false matches obtained comprising said item, and/or a second number associated with said reference biometric data item and equal to the number of pairs of false matches obtained comprising said item;calculating a bias score based on a maximum of the first numbers and/or based on a maximum of the second numbers.