Biometric Template Protection via XOR Codeword Encoding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Biometric security systems face challenges in securely storing and managing biometric reference data, as it is difficult to change or recover in case of loss, leading to security vulnerabilities.

Innovation Solution

A method involving quantization of feature components from biometric samples, assigning data bit sequences with specific Hamming distances, concatenating these into bit strings, and using an exclusive disjunction (XOR) operation with helper data to create a codeword for secure identity verification, incorporating error-correcting codes for robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If biometric reference data is stored in the system for comparison, then identity verification capability is improved, but security risk increases due to potential loss or compromise of the biometric data

Engineering Contradiction:
Improveidentity verification capabilityVSAvoidsecurity risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the necessary verification capability from the biometric data by using helper data and error-correcting codes. The actual biometric template is not stored in the database; instead, only helper data that enables verification is stored, thereby removing the security risk associated with storing complete biometric references while maintaining verification reliability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces helper data as an intermediary between the biometric sample and the verification process. This helper data, combined with error-correcting codes, acts as a mediator that enables identity verification without requiring storage of the actual biometric template, thus resolving the contradiction between verification capability and security risk

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If error-correcting codes are used to decode codewords, then measurement error tolerance is improved, but system complexity increases

Engineering Contradiction:
Improveerror toleranceVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies error-correcting codes during the enrollment phase to pre-process the biometric data and create helper data with built-in error correction capability. This preliminary action ensures that when verification occurs, the system can tolerate measurement errors without requiring complex real-time correction mechanisms, thus improving error tolerance while keeping verification complexity manageable

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP1932278B1Secure protection of biometric templates
Publication Date: 2017.05.10 KONINKLIJKE PHILIPS NV
  • EP1932278B1 patent drawingFigure 1
  • EP1932278B1 patent drawingFigure 2
  • EP1932278B1 patent drawingFigure 3

AI summary

This invention relates to methods and devices for verifying the identity of a person based on a sequence of feature components extracted from a biometric sample. Thereafter, the feature components are quantized and assigned a data bit sequence in such a way that adjacent quantization intervals have a Hamming distance of 1. The data bit sequences are concatenated into a bit string, and said bit string is combined with a helper data set by using an exclusive disjunction (XOR) operation into a codeword. Finally, the codeword is decoded into a secret V and a secret S is matched with the secret V.