Face Authentication via TEE-REE Segmentation

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Solution Overview

Problem

Executing face recognition software in the Trusted Execution Environment of mobile devices is slow due to high computing and memory requirements, especially for 3D face recognition, which compromises authentication speed.

Innovation Solution

The method involves acquiring biometric samples in the Trusted Execution Environment, transmitting them to the Rich Execution Environment for classification, and verifying intermediary outputs back in the Trusted Execution Environment, utilizing the Rich Execution Environment's computing power while ensuring security by random verification of a subset of outputs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If face recognition software is executed in the Trusted Execution Environment, then security is improved, but recognition time increases (speed deteriorates)

Engineering Contradiction:
ImprovesecurityVSAvoidrecognition time
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent divides the face recognition process into two segments: security-critical operations (biometric sample acquisition, verification) are executed in the Trusted Execution Environment, while computationally intensive operations (classification using neural networks) are executed in the Rich Execution Environment. This segmentation allows the system to leverage the security of TEE while utilizing the processing power of REE to avoid unacceptable recognition times.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary mechanism where biometric samples are transmitted from TEE to REE for classification, and intermediary outputs are transmitted back from REE to TEE for verification. This intermediary approach allows the system to benefit from both environments: the security of TEE and the processing power of REE, resolving the contradiction between security and speed.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If 3D face recognition is implemented, then reliability of recognition is improved, but computing power requirements increase (device complexity worsens)

Engineering Contradiction:
Improverecognition reliabilityVSAvoidcomputing power requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the computationally intensive 3D face recognition tasks (neural network classification) from security-critical tasks, executing the former in REE and the latter in TEE. This allows 3D face recognition to be implemented with high reliability while managing device complexity by distributing computational loads appropriately across different execution environments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables the mobile device to utilize multiple processing resources (CPU cores, GPU, neural network modules) in the REE for 3D face recognition while maintaining security through TEE verification. This multi-functional approach allows the system to handle complex 3D recognition tasks without requiring all high-performance components to be exclusively available to TEE.

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

Data Source

PatentUS11308188B2Method used in a mobile equipment with a trusted execution environment for authenticating a user based on his face
Publication Date: 2022.04.19 AMS INTERNATIONAL AG

AI summary

A method used in a mobile equipment for authenticating or identifying a user based on his face includes acquiring at least one biometric face sample corresponding to at least one image frame of the user in a Trusted Execution Environment of the mobile equipment, transmitting the biometric face sample to a Rich Execution Environment of the mobile equipment, and classifying at least one portion of the biometric face sample using a classifier in the Rich Execution Environment, so as to generate a set of intermediary outputs and preferably a classification result. The method further includes sending at least some of the intermediary outputs to the Trusted Execution Environment, and verifying at least some of the intermediary outputs in the Trusted Execution Environment.