Trust Zone Client Application Authentication via Source Hashing

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Solution Overview

Problem

In trust zone-based execution environments, there is a risk of malicious client applications disguising as legitimate ones, requesting unauthorized commands to trusted applications, which can compromise security services like encryption and digital rights management.

Innovation Solution

A method and device for authenticating client applications by executing them in a normal world, extracting and hashing source information, and providing this information along with signature and sub-certificates to the secure world for verification against a trusted application's root certificate, ensuring only authorized applications access secure services.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If arbitrary client applications can transmit commands to trusted applications using UUID, then ease of operation is improved, but security reliability deteriorates due to malicious programs disguising as legitimate applications

Engineering Contradiction:
Improveease of operationVSAvoidsecurity reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary authentication mechanism between the client application and trusted application. The system extracts source information from the client application, generates hash information, and verifies it against signature information and certificates. This intermediary verification process prevents malicious applications from directly commanding trusted applications while maintaining ease of use for legitimate applications.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements preliminary authentication actions before allowing client applications to access trusted applications. The system pre-extracts source information, pre-generates hash information, and pre-verified certificates and signature information. This preliminary verification ensures that only authenticated applications can subsequently communicate with trusted applications, addressing the security reliability issue before operation begins.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If authentication mechanisms are implemented to prevent malicious applications, then security reliability is improved, but device complexity increases due to additional verification steps

Engineering Contradiction:
Improvesecurity reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts only the essential authentication elements from the client application - specifically source information, hash information, signature information, and certificate data. By extracting only these critical verification components rather than analyzing the entire application, the system achieves improved security reliability while minimizing the increase in device complexity. The extracted information is then verified against pre-stored reference data.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses copying of authentication data in the form of hash information and certificate verification. Instead of analyzing the original client application code directly, the system creates and verifies cryptographic copies (hashes and digital signatures) of the application's identity information. This copying approach simplifies the verification process while maintaining high security standards, as the copied data can be efficiently compared against reference values.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3921749B1Device and method for authenticating application in execution environment in trust zone
Publication Date: 2024.07.24 SAMSUNG ELECTRONICS CO LTD
  • EP3921749B1 patent drawingFigure 1
  • EP3921749B1 patent drawingFigure 2
  • EP3921749B1 patent drawingFigure 3

AI summary

A device and a method for authenticating an application in an execution environment in a trust zone are provided. The method includes executing a client application (CA) in a normal world, receiving, in the normal world, a request for receiving a service of a trusted application (TA) of a secure world from the CA, acquiring, when the request is received in the normal world, source information of the CA loaded in a memory of the device, acquiring, in the normal world, first hash information from the source information, providing, to the secure world, the first hash information together with signature information and a sub certificate included in the CA, and authenticating the CA based on the sub certificate and a root certificate of the TA in the secure world.