Remote ATtestation procedureS (RATS) Architecture
draft-ietf-rats-architecture-22

[Ballot comment]
Thanks for the document. A few comments only.

#1 Figure 3

I cannot make sense of Figure 3. I understand the text in Section 3.2, so it might
not matter. But for instance the figure does not show to me at all that the bootloader
attested the kernel.

#2 Dark sides

Obviously, this architecture can be misused for bad things. It might be nice to have a section on this as per RFC 8280, but I am also not sure what to say other than "don't use this to restrict people based on discriminatory features".

#3  IPR

I am a little concerned about the IPR claims filed. Intel reserves the right to charge, and Huawei only allows free use for Section 4.3 and 6 despite that there is no Section 4.3 and it makes little sense for Section 6 ? I also believe that this document merely lists very generic concepts based on known prior art (but I am not a lawyer)

[Ballot comment]
I have very little to add, other than noting that I find Use-Case and Architecture documents to be really helpful.
They help "set the stage" when reading a new set of document, or deploying a new technology. Thank you!

[Ballot comment]
# GEN AD review of draft-ietf-rats-architecture-21

CC @larseggert

Thanks to Gyan S. Mishra for the General Area Review Team (Gen-ART) review
(https://mailarchive.ietf.org/arch/msg/gen-art/weBLFxmD2doRWhcZDm-kGjv8m0A).

## Comments

### Boilerplate

This document uses the RFC2119 keyword ['SHOULD'], but does not contain the
recommended RFC8174 boilerplate.

I don't think you need to add the boilerplate, simply rephrase the sentence
so it is more clear that you are in fact citing RFC4086 here?

### Inclusive language

Found terminology that should be reviewed for inclusivity; see
https://www.rfc-editor.org/part2/#inclusive_language for background and more
guidance:

* Terms `native` and `natively`; alternatives might be `built-in`,
  `fundamental`, `ingrained`, `intrinsic`, `original`

## Nits

All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

### Grammar/style

#### Section 2.6, paragraph 2
```
uthenticator. Relying Party: Any web site, mobile application back-end, or s
                                ^^^^^^^^
```
Nowadays, it's more common to write this as one word.

#### Section 3, paragraph 2
```
em component, device is often used as a illustrative synonym throughout this
                                      ^
```
Use "an" instead of "a" if the following word starts with a vowel sound, e.g.
"an article", "an hour".

#### Section 3, paragraph 4
```
l messages shown in Figure 1. Section Section 4 provides a more complete def
                              ^^^^^^^^^^^^^^^
```
Possible typo: you repeated a word.

#### Section 3.2, paragraph 4
```
-entity can be called an Attester. Among all the Attesters, there may be onl
                                  ^^^^^
```
Do not mix variants of the same word ("among" and "amongst") within a single
text. (Also elsewhere.)

#### Section 3.2, paragraph 5
```
final Evidence to the Verifier. Therefore the router is a composite device,
                                ^^^^^^^^^
```
A comma may be missing after the conjunctive/linking adverb "Therefore".

#### Section 3.2, paragraph 6
```
t that connects to the Verifier. Typically one router in the group is design
                                ^^^^^^^^^
```
A comma may be missing after the conjunctive/linking adverb "Typically".

#### Section 4.1, paragraph 9
```
ation (e.g., birth certificate) is the the Evidence, the passport is an Attes
                                  ^^^^^^^
```
Possible typo: you repeated a word.

#### Section 5.2, paragraph 7
```
e Verifier is an expected one by out of band establishment of key material, c
                                ^^^^^^^^^^^
```
Did you mean "out-of-band"?

#### Section 7.4, paragraph 1
```
e 1 illustrates the flow of a conceptual messages between various roles. This
                            ^^^^^^^^^^^^^^^^^^^^^
```
The plural noun "messages" cannot be used with the article "a". Did you mean "a
conceptual message" or "conceptual messages"?

#### Section 7.5, paragraph 1
```
n Attester, which can include privacy sensitive information as discussed in s
                              ^^^^^^^^^^^^^^^^^
```
This word is normally spelled with a hyphen.

#### Section 7.5, paragraph 2
```
ve information as discussed in section Section 11. Unlike Evidence, which is
                              ^^^^^^^^^^^^^^^
```
Possible typo: you repeated a word.

#### Section 9, paragraph 10
```
new epoch, such as by using a counter signed by the Epoch ID Distributor as
                              ^^^^^^^^^^^^^^
```
This word is normally spelled as one word.

#### Section 9, paragraph 10
```
essages that might be associated with a epoch ID that the receiver has not ye
                                      ^
```
Use "an" instead of "a" if the following word starts with a vowel sound, e.g.
"an article", "an hour".

#### Section 9, paragraph 11
```
ID approach minimizes the state kept to be independent of the number of Att
                                ^^^^^^^^^^
```
The verb "kept" is used with the gerund form.

#### Section 11, paragraph 7
```
avoid attacks where an attacker is able get a key they control endorsed. To s
                                  ^^^^^^^^
```
The preposition "to" is required before the verb "get".

#### Section 11, paragraph 8
```
authentication, * auditing, * fine grained access controls, and * logging. S
                              ^^^^^^^^^^^^
```
This word is normally spelled with a hyphen.

#### Section 12.1.1, paragraph 1
```
pants in a certain epoch of choice for ever, effectively freezing time. This
                                  ^^^^^^^^
```
The adverb "forever" is spelled as one word.

```
station Result contains an expiry time time(RX_v) then it could explicitly ch
                                  ^^^^^^^^^
```
Possible typo: you repeated a word.

#### Section 16.2, paragraph 20
```
it to its own clock or timestamps. Thus we use a suffix ("a" for Attester, "
                                    ^^^^
```
A comma may be missing after the conjunctive/linking adverb "Thus".

#### "Appendix A.", paragraph 3
```
me(EG_a)-time(VG_a) < Threshold. Similarly if, based on an Attestation Resul
                                ^^^^^^^^^
```
A comma may be missing after the conjunctive/linking adverb "Similarly".

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool

[Ballot comment]
Hi,

Thanks for this architecture document.  I only have a few minor/nit level comments:

Minor level comments:

(1) p 35, sec 10.4.  Discussion

  Implicit and explicit timekeeping can be combined into hybrid
  mechanisms.  For example, if clocks exist and are considered
  trustworthy but are not synchronized, a nonce-based exchange may be
  used to determine the (relative) time offset between the involved
  peers, followed by any number of timestamp based exchanges.

By trustworthy, I assume that this means that it is known that the clock on the device isn't suffering from clock skew?

Nit level comments:

(2) p 3, sec 1.  Introduction

  in making one's decision to trust it or not.  This is subtle

This is a subtle ...


(3) p 22, sec 5.3.  Combinations

      .-------------.
      |            | Compare Evidence
      |  Verifier  | against appraisal policy
      |            |
      '--------+----'
            ^  |
  Evidence |  | Attestation
            |  | Result
            |  v
      .----+--------.
      |            | Compare
      |  Relying  | Attestation Result
      |  Party 2  | against appraisal policy
      '--------+----'
            ^  |
  Evidence |  | Attestation
            |  | Result
            |  v
      .----+--------.              .-------------.
      |            +-------------->|            | Compare Attestation
      |  Attester  |  Attestation  |  Relying  | Result against
      |            |    Result    |  Party 1  | appraisal policy
      '-------------'              '-------------'

As a very minor nit, I'm surprised that the numbering of the relying parties is not the other way round, since presumably the flow talks to relying party 2 before relying party 1.  As alternative suggestion could be to label them something like "Main Relying Party" and "Secondary Relying Party".

Regards,
Rob

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Functions Operator has reviewed draft-ietf-rats-architecture-21, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

Sabrina Tanamal
Lead IANA Services Specialist

The following Last Call announcement was sent out (ends 2022-09-01):

From: The IESG
To: IETF-Announce
CC: Kathleen.Moriarty.ietf@gmail.com, draft-ietf-rats-architecture@ietf.org, rats-chairs@ietf.org, rats@ietf.org, rdd@cert.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Remote Attestation Procedures Architecture) to Informational RFC


The IESG has received a request from the Remote ATtestation ProcedureS WG
(rats) to consider the following document: - 'Remote Attestation Procedures
Architecture'
  as Informational RFC

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2022-09-01. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

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.
  An attempt is made to provide for a model that is neutral toward
  processor architectures, the content of claims, and protocols.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-rats-architecture/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/5042/
  https://datatracker.ietf.org/ipr/4106/

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Informational. The document describes the architecture for Remote Attestation Procedures, providing foundational information for developers and implementors. Yes, informational is appropriately indicated.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

  In Remote Attestation Procedures (RATS), one peer (the "Attester")
  produces believable information about itself - Evidence - to enable a
  remote peer (the "Relying Party") to decide whether to consider that
  Attester a trustworthy peer or not.  RATS are facilitated by an
  additional vital party, the Verifier.
 
This document describes the supporting architecture for RATS.

  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.
  An attempt is made to provide for a model that is neutral toward
  processor architectures, the content of claims, and protocols.

Working Group Summary:

This document represents a unification of the working group on architectural considerations. While earlier versions did come with some disagreement, this version has had very good cross working group participation and the editor team did a nice job of incorporating feedback as appropriate. The working group also reviewed IPR submitted and ultimately determined to go ahead with this informational document (see response to question #8 below).

Document Quality:

There are existing implementations of the RATS architecture and supporting documents. Industry points to RATS when discussing remote attestations to follow the standards being developed. The approach encompasses other existing formats and protocols that are well excepted for conveying, signing, and validating evidence. This document is an important one to explain the overall architecture and considerations for remote attestation, a very important capability for information security assurance. With industry's push for increased use of encryption, the endpoint must be more secure and there must be a way to detect variances from what is expected on a system. Attestation provides a simplified way to do this over previous posture assessment technologies. This particular document is very important toward the goal of understanding this simple, but complex set of standards.  The editors have done a nice job of working through the identified issues.

Personnel:

Document Shepherd: Kathleen Moriarty
Responsible Area Director: Roman Danyliw

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The document shepherd has followed the progress of this document from its inception and the merger of two prior documents. The shepherd has provided multiple reviews and all comments were addressed. The shepherd, WG Chairs, and AD also followed the IPR review process and documented WG agreement to proceed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed? No

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
No.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
No Concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes, each author has confirmed all IPR disclosures appropriate have been submitted.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
There was an extended review process of the working group on submitted IPR for this informational document. The outcome of this process was to proceed with publication. The summary of this agreement is noted in the responsible Area Director's message to the list with references to input from working group participants. https://mailarchive.ietf.org/arch/msg/rats/3nCTOkNYW8ydEo0zHZlQoY8F92A/

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
There is strong consensus among the working group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
No.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
No extra reviews were required (or appropriate).

(13) Have all references within this document been identified as either normative or informative?
Yes.

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
No.

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
There are no downrefs.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No.

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
There are no IANA considerations in this document.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
N/A

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A, reviews of diagrams and tables only.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Informational. The document describes the architecture for Remote Attestation Procedures, providing foundational information for developers and implementors. Yes, informational is appropriately indicated.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

  In Remote Attestation Procedures (RATS), one peer (the "Attester")
  produces believable information about itself - Evidence - to enable a
  remote peer (the "Relying Party") to decide whether to consider that
  Attester a trustworthy peer or not.  RATS are facilitated by an
  additional vital party, the Verifier.
 
This document describes the supporting architecture for RATS.

  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.
  An attempt is made to provide for a model that is neutral toward
  processor architectures, the content of claims, and protocols.

Working Group Summary:

This document represents a unification of the working group on architectural considerations. While earlier versions did come with some disagreement, this version has had very good cross working group participation and the editor team did a nice job of incorporating feedback as appropriate. The working group also reviewed IPR submitted and ultimately determined to go ahead with this informational document (see response to question #8 below).

Document Quality:

There are existing implementations of the RATS architecture and supporting documents. Industry points to RATS when discussing remote attestations to follow the standards being developed. The approach encompasses other existing formats and protocols that are well excepted for conveying, signing, and validating evidence. This document is an important one to explain the overall architecture and considerations for remote attestation, a very important capability for information security assurance. With industry's push for increased use of encryption, the endpoint must be more secure and there must be a way to detect variances from what is expected on a system. Attestation provides a simplified way to do this over previous posture assessment technologies. This particular document is very important toward the goal of understanding this simple, but complex set of standards.  The editors have done a nice job of working through the identified issues.

Personnel:

Document Shepherd: Kathleen Moriarty
Responsible Area Director: Roman Danyliw

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The document shepherd has followed the progress of this document from its inception and the merger of two prior documents. The shepherd has provided multiple reviews and all comments were addressed. The shepherd, WG Chairs, and AD also followed the IPR review process and documented WG agreement to proceed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed? No

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
No.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
No Concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes, each author has confirmed all IPR disclosures appropriate have been submitted.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
There was an extended review process of the working group on submitted IPR for this informational document. The outcome of this process was to proceed with publication. The summary of this agreement is noted in the responsible Area Director's message to the list with references to input from working group participants. https://mailarchive.ietf.org/arch/msg/rats/3nCTOkNYW8ydEo0zHZlQoY8F92A/

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
There is strong consensus among the working group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
No.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
No extra reviews were required (or appropriate).

(13) Have all references within this document been identified as either normative or informative?
Yes.

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
No.

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
There are no downrefs.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No.

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
There are no IANA considerations in this document.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
N/A

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A, reviews of diagrams and tables only.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Informational. The document describes the architecture for Remote Attestation Procedures, providing foundational information for developers and implementors. Yes, informational is appropriately indicated.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

  In Remote Attestation Procedures (RATS), one peer (the "Attester")
  produces believable information about itself - Evidence - to enable a
  remote peer (the "Relying Party") to decide whether to consider that
  Attester a trustworthy peer or not.  RATS are facilitated by an
  additional vital party, the Verifier.
 
This document describes the supporting architecture for RATS.

  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.
  An attempt is made to provide for a model that is neutral toward
  processor architectures, the content of claims, and protocols.

Working Group Summary:

This document represents a unification of the working group on architectural considerations. While earlier versions did come with some disagreement, this version has had very good cross working group participation and the editor team did a nice job of incorporating feedback as appropriate. The working group also reviewed IPR submitted and ultimately determined to go ahead with this informational document (see response to question #8 below).

Document Quality:

There are existing implementations of the RATS architecture and supporting documents. Industry points to RATS when discussing remote attestations to follow the standards being developed. The approach encompasses other existing formats and protocols that are well excepted for conveying, signing, and validating evidence. This document is an important one to explain the overall architecture and considerations for remote attestation, a very important capability for information security assurance. With industry's push for increased use of encryption, the endpoint must be more secure and there must be a way to detect variances from what is expected on a system. Attestation provides a simplified way to do this over previous posture assessment technologies. This particular document is very important toward the goal of understanding this simple, but complex set of standards.  The editors have done a nice job of working through the identified issues.

Personnel:

Document Shepherd: Kathleen Moriarty
Responsible Area Director: Roman Danyliw

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The document shepherd has followed the progress of this document from its inception and the merger of two prior documents. The shepherd has provided multiple reviews and all comments were addressed. The shepherd, WG Chairs, and AD also followed the IPR review process and documented WG agreement to proceed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed? No

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
No.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
No Concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?
Yes, each author has confirmed all IPR disclosures appropriate have been submitted.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.
There was an extended review process of the working group on submitted IPR for this informational document. The outcome of this process was to proceed with publication. The summary of this agreement is noted in the responsible Area Director's message to the list with references to input from working group participants. https://mailarchive.ietf.org/arch/msg/rats/3nCTOkNYW8ydEo0zHZlQoY8F92A/

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
There is strong consensus among the working group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
No.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
No extra reviews were required (or appropriate).

(13) Have all references within this document been identified as either normative or informative?
Yes.

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
No.

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
There are no downrefs.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No.

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
There are no IANA considerations in this document.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
N/A

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A, reviews of diagrams and tables only.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?
Informational. The document describes the architecture for Remote Attestation Procedures, providing foundational information for developers and implementors. Yes, informational is appropriately indicated.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

  In Remote Attestation Procedures (RATS), one peer (the "Attester")
  produces believable information about itself - Evidence - to enable a
  remote peer (the "Relying Party") to decide whether to consider that
  Attester a trustworthy peer or not.  RATS are facilitated by an
  additional vital party, the Verifier.
 
This document describes the supporting architecture for RATS.

  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.
  An attempt is made to provide for a model that is neutral toward
  processor architectures, the content of claims, and protocols.

Working Group Summary:

This document represents a unification of the working group on architectural considerations. While earlier versions did come with some disagreement, this version has had very good cross working group participation and the editor team did a nice job of incorporating feedback as appropriate.

Document Quality:

There are existing implementations of the RATS architecture and supporting documents. Industry points to RATS when discussing remote attestations to follow the standards being developed. The approach encompasses other existing formats and protocols that are well excepted for conveying, signing, and validating evidence. This document is an important one to explain the overall architecture and considerations for remote attestation, a very important capability for information security assurance. With industry's push for increased use of encryption, the endpoint must be more secure and there must be a way to detect variances from what is expected on a system. Attestation provides a simplified way to do this over previous posture assessment technologies. This particular document is very important toward the goal of understanding this simple, but complex set of standards.  The editors have done a nice job of working through the identified issues.

Personnel:

Document Shepherd: Kathleen Moriarty
Responsible Area Director: Roman Danyliw

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.
The document shepherd has followed the progress of this document from its inception and the merger of two prior documents. The shepherd has provided multiple reviews and all comments were addressed.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed? No

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.
No.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.
No Concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?
There is strong consensus among the working group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise the areas of conflict in separate email messages to the Responsible Area Director. (It should be in a separate email because this questionnaire is publicly available.)
No.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
No extra reviews were required (or appropriate).

(13) Have all references within this document been identified as either normative or informative?
Yes.

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?
No.

(15) Are there downward normative references references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.
There are no downrefs.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.
No.

(17) Describe the Document Shepherd's review of the IANA considerations section, especially with regard to its consistency with the body of the document. Confirm that all protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).
There are no IANA considerations in this document.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.
N/A

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.
N/A, reviews of diagrams and tables only.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) for syntax and formatting validation? If there are any resulting errors or warnings, what is the justification for not fixing them at this time? Does the YANG module comply with the Network Management Datastore Architecture (NMDA) as specified in RFC8342?
N/A