HW TEE Secure Channels with Nonce-Bound Payload Attestation

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Solution Overview

Problem

Existing hardware-based Trusted Execution Environments (HW TEEs) from different vendors have non-interoperable attestation mechanisms, lack assurance of continued communication with the same attested payload, and do not provide built-in means to guarantee secure provisioning of secrets, making it difficult for cloud service providers to establish secure channels with payloads.

Innovation Solution

A method is introduced to establish a secure channel between a party and a software payload running in a HW TEE by using a nonce mixed with a payload public key for attestation, generating a session key, and providing persistent storage for authentication means, allowing secure communication and provisioning of secrets.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If HW TEEs from different vendors use their own attestation mechanisms, then each vendor can ensure basic security features, but the attestation mechanisms are not interoperable among different vendors

Engineering Contradiction:
Improvesecurity guaranteeVSAvoidinteroperability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a standardized attestation interface as an intermediary layer between diverse HW TEE implementations and the verification system. This interface translates vendor-specific attestation mechanisms into a common format, enabling interoperability while preserving the security guarantees of each vendor's implementation. The standardized interface acts as a mediator that allows different HW TEEs to communicate through a unified protocol.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a universal attestation framework that can work with multiple HW TEE vendors simultaneously. By defining a common attestation interface that supports various underlying hardware implementations, the system achieves multi-functionality where a single verification mechanism can validate attestation from different vendors without requiring vendor-specific customization.

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

2Ease of operation

If attestation is performed without binding to subsequent communication, then the attestation process is simple, but there is no guarantee that subsequent communication occurs with the same attested payload

Engineering Contradiction:
Improveattestation process simplicityVSAvoidpayload identity assurance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent performs preliminary binding of the attestation to the communication channel by incorporating the payload's public key into the attestation process before any secret provisioning occurs. This preliminary action creates a cryptographic link between the attested payload and the communication channel, ensuring that subsequent communications are guaranteed to occur with the same attested payload while maintaining operational simplicity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If cloud service providers directly handle attestation processes, then attestation can be performed, but the CSP is exposed to attestation processes and security risks

Engineering Contradiction:
Improveattestation verificationVSAvoidCSP security exposure
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts the attestation verification logic from the cloud service provider infrastructure and places it within the hardware-based trusted execution environment. By moving the attestation process into the HW TEE boundary, the CSP is removed from the security-critical attestation path, eliminating their exposure to potential compromise while maintaining the ability to verify attestation through the standardized interface.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4423970B1Method to establish a secure channel
Publication Date: 2025.07.16 THALES DIS FRANCE SA
  • EP4423970B1 patent drawingFigure 1
  • EP4423970B1 patent drawingFigure 2
  • EP4423970B1 patent drawingFigure 3

AI summary

The present invention provides a method to establish a secure channel between the party of a software payload and the software payload itself when running into a hardware-based trusted execution environment, HW TEE, at the instance of a cloud service provider, the method comprising the following steps: sending, by the party, at least a nonce to the software payload; generating, by the software payload, a payload key pair: public key and private key; mixing, by the software payload, the payload public key with the nonce; computing, by the HW TEE, an attestation using at least this nonce mixed with the payload public key; sending, by the software payload, at least the attestation, and the payload public key to the party; verifying, by the party, the attestation using the sent nonce mixed with the received payload public key; generating, by the software payload and the party, a session key between them; and establishing a secure channel between the party and the software payload running into the HW TEE.