Introduction ============ Relying parties require evidence about the trustworthiness of remote system components [RFC4949] they interact with. Remote attestation procedures (RATS) enable relying parties to establish a level of confidence in the trustworthiness of remote system components by creating and processing attestation evidence. Based on the provided evidence, a relying party can decide whether to consider a remote system component trustworthy or not. 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, * assertion/claim origination or provenance, * manufacturing origin, * system component integrity, * system component configuration, or * operational state and measurements of steps which led to the operational state. While domain-specific attestation mechanisms such as Trusted Computing Group (TCG) Trusted Platform Module (TPM)/Trusted 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. Goals ===== This WG will standardize formats for describing assertions/claims about system components and associated evidence; and procedures and protocols to convey and appraise these assertions/claims by the relying parties. The working group will cooperate and coordinate with other IETF WG such as TEEP, SUIT and SACM as appropriate. The WG will also evaluate prior work such as NEA and proprietary attestation technologies. Program of Work =============== The working group will develop standards supporting interoperable remote attestation procedures for system components that incorporate roots of trust. The main deliverables are as follows: 1. Specify a terminology, architecture and use cases that enable explicit (a set of verifiable assertion/claims is transported in the attestation) and implicit (a set of assertions/claims is implied by possession of a secret) attestation techniques. The architecture may include a system security model for the signing key material and involve at least the system component, system component provider, and the relying authority. 2. Standardize an information model for assertions/claims which provide information about system components characteristics scoped by the specified use-cases. 3. Standardize data models that implements and secures the defined information model (e.g., CBOR Web Token structures [RFC8392], JSON Web Token structures [RFC7519]). 4. Standardize interoperable protocols to securely convey assertions/claims. 5. Standardize interoperable protocols to appraise attestation evidence via reference values.