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Remote ATtestation ProcedureS (rats)

WG Name Remote ATtestation ProcedureS
Acronym rats
Area Security Area (sec)
State Active
Charter charter-ietf-rats-02 Approved
Document dependencies
Additional resources Issue tracker, Wiki, Zulip Stream
Personnel Chairs Kathleen Moriarty, Nancy Cam-Winget, Ned Smith
Area Director Deb Cooley
Mailing list Address
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Chat Room address

Charter for Working Group


In network protocol exchanges, it is often the case that one entity (a Relying Party) requires evidence about the remote peer (and system components [RFC4949] thereof), in order to assess the trustworthiness of the peer. Remote attestation procedures (RATS) determine whether relying parties can establish a level of confidence in the trustworthiness of remote peers, called Attesters. The objective is achieved by a two-stage appraisal procedure facilitated by a trusted third party, called Verifier, with trusted links to the supply chain.

The procedures for the two stages are:

  • Evidence Appraisal: a Verifier applies policy and supply chain input, such as Endorsements and References Values, to create Attestation Results from Evidence.

  • Attestation Results Appraisal: a Relying Party applies policy to Attestation Results associated with an Attester's Evidence that originates from a trusted Verifier. The results are trust decisions regarding the Attester.

To improve the confidence in a system component's trustworthiness, a relying party may require evidence about:

  • system component identity,
  • composition of system components, including nested components,
  • roots of trust,
  • an assertion/claim origination or provenance,
  • manufacturing origin,
  • system component integrity,
  • system component configuration,
  • operational state and measurements of steps which led to the operational state, or

  • other factors that could influence trust decisions.

While domain-specific attestation mechanisms such as Trusted Computing Group (TCG) Trusted Platform Module (TPM)/TPM Software Stack (TSS), Fast Identity Online (FIDO) Alliance attestation, and Android Keystore attestation exist, there is no interoperable way to create and process attestation evidence to make determinations about system components among relying parties of different manufactures and origins.


The WG has defined an architecture (draft-ietf-rats-architecture) for remote attestation. The WG will standardize formats for describing evidence and attestation results and the associated procedures and protocols to convey evidence for appraisal to a verifier and attestation results to a relying party. Additionally, the WG will standardize formats for endorsements and reference values, and may apply and/or profile existing protocols (e.g., DTLS, CoAP, or MUD) to convey them to the verifier. Formats and protocols for appraisal policy for evidence and appraisal policy for attestation results are out of scope.

The WG will continue to cooperate and coordinate with other IETF WGs such as TEEP, SUIT, CoRE, ACE, and CBOR; and work with organizations in the community, such as the TCG, Global Platform, and the FIDO Alliance, as appropriate.

Program of Work

The working group will develop standards supporting interoperable remote attestation procedures for system components. The main deliverables are as follows:

  1. Specify use cases for remote attestation (to document and achieve WG consensus but not expected to be published as an RFC).

  2. Specify augmentations to the RATS architecture (draft-ietf-rats-architecture) in support of specific attestation techniques.

  3. Standardize an information model for evidence and attestations results scoped by the specified use-cases.

  4. Standardize data models that implement and secure the defined information model (e.g., CBOR Web Token structures [RFC8392], JSON Web Token structures [RFC7519]).

  5. If feasible, use or extend existing protocols to securely convey evidence and attestation results, or if not, then standardize interoperable protocols for this purpose.

  6. Standardize interoperable data formats to securely declare and convey endorsements and reference values.


Date Milestone Associated documents
Jul 2024 Submit EAT Media types for publication draft-ietf-rats-eat-media-type
Mar 2024 Submit Concise Reference Integrity and Endorsement Manifests for publication draft-ietf-rats-corim
Dec 2023 Submit Entity Attestation Token for publication draft-ietf-rats-eat
Dec 2023 Submit Reference Interaction Models to WGLC draft-ietf-rats-reference-interaction-models
Dec 2023 Submit CBOR Tag for Unprotected CWT Claim sets for publication draft-ietf-rats-uccs
Dec 2023 Submit Network Device Subscription to WGLC draft-ietf-rats-network-device-subscription
Dec 2023 Submit Direct Anonymous Attestation for RATs for publication draft-ietf-rats-daa
Dec 2023 Submit Attestation Results for Secure Interactions for publication draft-fv-rats-ear
Dec 2023 Submit Direct Anonymous Attestation for RATs to WGLC draft-ietf-rats-daa
Dec 2023 Submit Concise Reference Integrity and Endorsement Manifests to WGLC draft-ietf-rats-corim
Nov 2023 Submit Network Device Subscription for publication draft-ietf-rats-network-device-subscription
Nov 2023 Submit Reference Interaction Models draft-ietf-rats-reference-interaction-models
Nov 2023 Submit Attestation Results for Secure Interactions for WGLC draft-ietf-rats-ar4si
Jul 2023 Submit CBOR Tag for Unprotected CWT Claim sets to WGLC draft-ietf-rats-uccs

Done milestones

Date Milestone Associated documents
Done Submit EAT Media types to WGLC draft-ietf-rats-eat-media-type
Done Call for adoption on Concise Reference Integrity and Endorsement Manifests draft-ietf-rats-corim