RFC 9334 - Remote ATtestation procedureS (RATS) Architecture

Abstract

In network protocol exchanges, it is often useful for one end of a communication to know whether the other end is in an intended operating state. This document provides an architectural overview of the entities involved that make such tests possible through the process of generating, conveying, and evaluating evidentiary Claims. It provides a model that is neutral toward processor architectures, the content of Claims, and protocols.

Status of This Memo

This document is not an Internet Standards Track specification; it is published for informational purposes.

This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841.

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc9334.

Copyright Notice

Copyright (c) 2023 IETF Trust and the persons identified as the document authors. All rights reserved.

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.

Contents

• 1. Introduction
• 2. Reference Use Cases
  • 2.1. Network Endpoint Assessment
  • 2.2. Confidential Machine Learning Model Protection
  • 2.3. Confidential Data Protection
  • 2.4. Critical Infrastructure Control
  • 2.5. Trusted Execution Environment Provisioning
  • 2.6. Hardware Watchdog
  • 2.7. FIDO Biometric Authentication
• 3. Architectural Overview
  • 3.1. Two Types of Environments of an Attester
  • 3.2. Layered Attestation Environments
  • 3.3. Composite Device
  • 3.4. Implementation Considerations
• 4. Terminology
  • 4.1. Roles
  • 4.2. Artifacts
• 5. Topological Patterns
  • 5.1. Passport Model
  • 5.2. Background-Check Model
  • 5.3. Combinations
• 6. Roles and Entities
• 7. Trust Model
  • 7.1. Relying Party
  • 7.2. Attester
  • 7.3. Relying Party Owner
  • 7.4. Verifier
  • 7.5. Endorser, Reference Value Provider, and Verifier Owner
• 8. Conceptual Messages
  • 8.1. Evidence
  • 8.2. Endorsements
  • 8.3. Reference Values
  • 8.4. Attestation Results
  • 8.5. Appraisal Policies
• 9. Claims Encoding Formats
• 10. Freshness
  • 10.1. Explicit Timekeeping Using Synchronized Clocks
  • 10.2. Implicit Timekeeping Using Nonces
  • 10.3. Implicit Timekeeping Using Epoch IDs
  • 10.4. Discussion
• 11. Privacy Considerations
• 12. Security Considerations
  • 12.1. Attester and Attestation Key Protection
    • 12.1.1. On-Device Attester and Key Protection
    • 12.1.2. Attestation Key Provisioning Processes
  • 12.2. Conceptual Message Protection
  • 12.3. Attestation Based on Epoch ID
  • 12.4. Trust Anchor Protection
• 13. IANA Considerations
• 14. References
  • 14.1. Normative References
  • 14.2. Informative References
• Appendix A. Time Considerations
  • A.1. Example 1: Timestamp-Based Passport Model
  • A.2. Example 2: Nonce-Based Passport Model
  • A.3. Example 3: Passport Model Based on Epoch ID
  • A.4. Example 4: Timestamp-Based Background-Check Model
  • A.5. Example 5: Nonce-Based Background-Check Model
• Acknowledgments
• Contributors
• Authors' Addresses

Document Information

• RFC Number: 9334
• Category: Informational
• Published: January 2023
• ISSN: 2070-1721
• Authors: H. Birkholz (Fraunhofer SIT), D. Thaler (Microsoft), M. Richardson (Sandelman Software Works), N. Smith (Intel), W. Pan (Huawei)