[Rats] RFC 9999 on Remote ATtestation procedureS (RATS) Conceptual Message Wrapper (CMW)

A new Request for Comments is now available in online RFC libraries.

        RFC 9999

        Title:      Remote ATtestation procedureS (RATS) Conceptual Message Wrapper (CMW)
        Author:     H. Birkholz,
                    N. Smith,
                    T. Fossati,
                    H. Tschofenig
        Status:     Proposed Standard
        Stream:     IETF
        Date:       July 2026
        Mailbox:    henk.birkholz@ietf.contact,
                    ned.smith.ietf@outlook.com,
                    tho.ietf@gmail.com,
                    Hannes.Tschofenig@gmx.net
        Pages:      35

        I-D Tag:    draft-ietf-rats-msg-wrap-23

        URL:        https://www.rfc-editor.org/info/rfc9999

        DOI:        10.17487/RFC9999

The conceptual messages introduced by the Remote ATtestation procedureS (RATS) architecture (RFC 9334) are protocol-agnostic data units that are conveyed between RATS roles during RATS interactions. Conceptual messages describe the meaning and function of such data units within RATS data flows without specifying a wire format, encoding, transport mechanism, or processing details. The initial set of conceptual messages is defined in Section 8 of RFC 9334 and includes Evidence, Attestation Results, Endorsements, Reference Values, and Appraisal Policies.

This document introduces the Conceptual Message Wrapper (CMW) that provides a common structure to encapsulate these messages. It defines a dedicated Concise Binary Object Representation (CBOR) tag, corresponding JSON Web Token (JWT) and CBOR Web Token (CWT) claims, and an X.509 extension.

Together, these mechanisms allow CMWs to be used in CBOR-based protocols, web APIs using JWTs and CWTs, and PKIX artifacts such as X.509 certificates. Additionally, this document defines media types and CoAP Content-Formats that may be used to identify CMWs when transported over protocols such as HTTP, MIME, and CoAP.

The goal is to improve the interoperability and flexibility of remote attestation protocols. Introducing a shared message format such as CMW enables consistent support for different attestation message types, enables the evolution of message serialization formats without breaking compatibility, and avoids the need to redefine how messages are handled within each protocol.

This document is a product of the Remote ATtestation ProcedureS Working Group of the IETF.

STANDARDS TRACK: This document specifies an Internet Standards Track
protocol for the Internet community, and requests discussion and
suggestions for improvements. Distribution of this memo is unlimited.

This announcement is sent to the IETF-Announce and rfc-dist lists.
To subscribe or unsubscribe, see
  https://www.ietf.org/mailman/listinfo/ietf-announce
  https://mailman.rfc-editor.org/mailman/listinfo/rfc-dist

For searching the RFC series, see https://www.rfc-editor.org/search/
For downloading RFCs, see https://www.rfc-editor.org/series/rfc-download/

Requests for special distribution should be addressed to either the
author of the RFC in question, or to rfc-editor@rfc-editor.org.  Unless
specifically noted otherwise on the RFC itself, all RFCs are for
unlimited distribution.

The RFC Editor Team