Facial Dynamics Verification for Anti-Spoofing

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Solution Overview

Problem

Traditional face recognition systems are vulnerable to spoofing attacks, where malicious actors can gain access by presenting photographs or three-dimensional models that duplicate the appearance of authorized users, and existing liveness tests can be circumvented.

Innovation Solution

A computer-implemented technique that verifies identity through two phases of face analysis: first, by matching captured face information against a structural face signature describing pose-invariant characteristics, and second, by matching dynamic face signatures that encode movement and relations of face parts during gestures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional face recognition systems use pose-invariant features and liveness tests, then basic identity verification is achieved, but the system remains vulnerable to spoofing attacks using photographs or three-dimensional models

Engineering Contradiction:
Improveanti-spoofing capabilityVSAvoidface analysis complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The face verification process is segmented into two distinct phases: enrollment-phase analysis capturing structural face information, and verification-phase analysis comparing both structural and dynamic characteristics. This segmentation allows the system to handle complexity in manageable stages while improving reliability through multi-phase validation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from static face recognition to dynamic verification by capturing and analyzing face dynamics during gesture performance. The verification-phase face information includes temporal variations as the user performs gestures, making spoofing with static photographs or models ineffective.

Inventive Principle:
Principle #15Dynamics

2Reliability

If liveness tests require successive actions, then spoofing resistance improves, but malicious actors can still present static snapshots of these actions

Engineering Contradiction:
Improveliveness detection accuracyVSAvoidspoofing countermeasure effectiveness
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system requires continuous capture of face dynamics throughout the entire gesture performance rather than discrete snapshots. The verification process analyzes the continuous temporal evolution of face information, ensuring that spoofing attempts with static or pre-recorded images cannot succeed.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The enrollment-phase face information is captured and stored in advance, establishing a baseline of genuine face dynamics. This preliminary data is then used to train or configure the verification system, enabling it to recognize authentic gesture patterns and reject spoofing attempts.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If face recognition systems capture detailed face information, then verification accuracy improves, but the risk of spoofing through duplicate appearance increases

Engineering Contradiction:
Improveface matching accuracyVSAvoidspoofing vulnerability
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system adds the temporal dimension to face verification by analyzing how face characteristics change over time during gestures. This transforms the verification from a two-dimensional spatial comparison to a three-dimensional spatio-temporal analysis, making it impossible to spoof with static images while maintaining high accuracy.

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

Data Source

PatentUS10776470B2Verifying identity based on facial dynamics
Publication Date: 2020.09.15 MICROSOFT TECHNOLOGY LICENSING LLC
  • US10776470B2 patent drawing
  • US10776470B2 patent drawing
  • US10776470B2 patent drawing

AI summary

A computer-implemented technique is described for verifying the identity of a user using two components of face analysis. In a first part, the technique determines whether captured face information matches a previously stored structural face signature pertaining to the user. The structural face signature describes, at least in part, gross structural characteristics of the face that are largely invariant from pose to pose. In the second part, the technique determines whether the captured face information matches a dynamic face signature associated with the user. The dynamic face signature describes movement of parts of the face over a span of time as the user performs a gesture, and the correlation of different parts of the face during the movement. The technique reduces the risk that a malicious actor can successfully artificially duplicate the appearance of an authorized user.