Code change:
6. An entity in the RATS architecture includes at least one of the roles <del> defined in this document.  As a result, the entity can participate as a constituent of the RATS architecture.  Additionally, an entity can aggregate more than one role into itself.  These collapsed roles combine the duties of multiple roles.  In these cases, interaction between these roles do not necessarily use the Internet Protocol. They can be using a loopback device or other IP-based communication between separate environments, but they do not have to.  Alternative channels to convey conceptual messages include function calls, sockets, GPIO interfaces, local busses, or hypervisor calls.  This type of conveyance is typically found in Composite Devices.  Most importantly, these conveyance methods are out-of-scope of RATS, but they are presumed to exist in order to convey conceptual messages appropriately between roles. </del> <ins> defined in this document.  An entity can aggregate more than one role into itself.  These collapsed roles combine the duties of multiple roles. In these cases, interaction between these roles do not necessarily use the Internet Protocol.  They can be using a loopback device or other IP-based communication between separate environments, but they do not have to.  Alternative channels to convey conceptual messages include function calls, sockets, GPIO interfaces, local busses, or hypervisor calls.  This type of conveyance is typically found in Composite Devices.  Most importantly, these conveyance methods are out-of-scope of RATS, but they are presumed to exist in order to convey conceptual messages appropriately between roles. </ins> For example, an entity that both connects to a wide-area network and to a system bus is taking on both the Attester and Verifier roles.

Related discussion:
text: Proposed: "It is also worth pointing out that the choice of model is generally up to the Relying Party. The same device may need to create Evidence for different Relying Parties and/or different use cases. For instance, a network infrastructure device may attest evidence to gain access to the network or a server holding confidential data may require attestations of evidence to gain access to the data. As such, both models may simultaneously be in use by the same device." Section 6: The first 3 sentences are fine, but if you wanted to reduce it, it could be one sentence. Current: "An entity in the RATS architecture includes at least one of the roles defined in this document. As a result, the entity can participate as a constituent of the RATS architecture. Additionally, an entity can aggregate more than one role into itself. " Proposed: "An entity in the RATS architecture includes at least one [or more] of the roles defined in this document. " Or more is redundant, so that really isn't necessary to convey the same point. Then the last sentence: I'd change it a little from: "In essence, an entity that combines more than one role also creates and consumes the corresponding conceptual messages as defined in this document." To: "In essence, an entity that combines more than one role may create and consume the corresponding conceptual messages as defined in this document." It might not, it could be the verifier and relying party. Section 5: Consider changing from: "That is, it might appraise the trustworthiness of an application component, or operating system component or service, under the assumption that information provided about it by the lower-layer hypervisor or firmware is true. " To: "That is, it might appraise the trustworthiness of an application component, operating system component, or service under the assumption that information provided about it by the lower-layer hypervisor or firmware is true. " Section 7: I'd say it's really a stronger level of assurance of security rather than a stronger level of security in the following: "A stronger level of security comes when information can be vouched for by hardware or by ROM code, especially if such hardware is physically resistant to hardware tampering. "