Subject: [Rats] Fwd: New Version Notification for draft-birkholz-rats-reference-interaction-model-03.txt

From: Henk Birkholz <[email-masked]>
Date: Wed, 8 Jul 2020 08:52:50 +0200

Hi list,

this version of the reference interaction models I-D now includes the 
three main models that are used across several related documents:

* challenge/response remote attestation (charra)
* uni-directional remote attestation, and
* streaming remote attestation

New diagrams for all three interaction models can be found in section 8:

> https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model#section-8

As an attester's identity is vital to all interaction models in RATS -- 
but also has severe implications -- we welcome Liqun and Chris as 
co-authors. They are experts for direct anonymous attestation (DAA) and 
remote attestation in general.

An overview about DAA can be found in section 5:

> https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model#section-5

Viele Grüße,

Henk

-------- Forwarded Message --------
Subject: New Version Notification for 
draft-birkholz-rats-reference-interaction-model-03.txt
Date: Tue, 7 Jul 2020 23:41:20 -0700
From: [email-masked]
To: Liqun Chen <[email-masked]>, Michael Eckel 
<[email-masked]>, Christopher Newton 
<[email-masked]>, Henk Birkholz <[email-masked]>

A new version of I-D, draft-birkholz-rats-reference-interaction-model-03.txt
has been successfully submitted by Henk Birkholz and posted to the
IETF repository.

Name:		draft-birkholz-rats-reference-interaction-model
Revision:	03
Title:		Reference Interaction Models for Remote Attestation Procedures
Document date:	2020-07-08
Group:		Individual Submission
Pages:		22
URL: 
https://www.ietf.org/internet-drafts/draft-birkholz-rats-reference-interaction-model-03.txt
Status: 
https://datatracker.ietf.org/doc/draft-birkholz-rats-reference-interaction-model/
Htmlized: 
https://tools.ietf.org/html/draft-birkholz-rats-reference-interaction-model-03
Htmlized: 
https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model
Diff: 
https://www.ietf.org/rfcdiff?url2=draft-birkholz-rats-reference-interaction-model-03

Abstract:
    This document describes interaction models for remote attestation
    procedures (RATS).  Three conveying mechanisms - Challenge/Response,
    Uni-Directional, and Streaming Remote Attestation - are illustrated
    and defined.  Analogously, a general overview about the information
    elements typically used by corresponding conveyance protocols are
    highlighted.  Privacy preserving conveyance of Evidence via Direct
    Anonymous Attestation is elaborated on for each interaction model,
    individually.

Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.

The IETF Secretariat

---

From: Anders Rundgren <[email-masked]>
Date: Wed, 8 Jul 2020 13:17:56 +0200

> Hi list,

Hi Henk,

> * streaming remote attestation

This is great but I don't see that the session-based attestation concept[1] used in Saturn[2,3], is covered by this I-D.

Best regards,
Anders

1] https://cyberphone.github.io/doc/research/session-based-remote-attestation.pdf

2] https://cyberphone.github.io/openbankingwallet
3] https://cyberphone.github.io/doc/security/keygen2.html

> _______________________________________________
> RATS mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/rats
>

---

From: Henk Birkholz <[email-masked]>
Date: Wed, 8 Jul 2020 14:24:11 +0200

Hi Anders,

thanks for your reach-out :) As far as I know, session-based creation of 
evidence is map-able to every kind of interaction model. I'll quickly 
illustrate how I think that typically works. Please step in, if I am 
erring here.

Session-based remote attestation "bundles" a certain amount of 
"evidence-generating primitive operations" of an Attesting Environment 
in a way that corresponding results are packaged in relative large set 
of Claims collected over time - in one piece of evidence.

Some solutions call these bundles audit sessions. If these bundles 
constitute evidence that can represent past states, some solutions call 
the resulting evidence secure audit logs.

Looking at the referenced write-up [1], the audit approach seems to be 
combined with a roll-back feature. That is an implementation feature for 
remediation that is typically not directly in-scope of RATS. But - RATS 
of course play a vital role in assessing the need for & and the result 
of remediation procedures, as well as selecting appropriate remediation 
procedures in the first place (see TEEP).

In summary, my early feedback is that the illustrated Protected API can 
be mapped to all three interaction model - it was probably designed with 
CHARRA in mind. Maybe it is useful to note here that a subscription 
session is not the same thing as an audit session.

Viele Grüße,

Henk

On 08.07.20 13:17, Anders Rundgren wrote:
> This is great but I don't see that the session-based attestation 
> concept[1] used in Saturn[2,3], is covered by this I-D.
> 
> Best regards,
> Anders
> 
> 1] 
> https://cyberphone.github.io/doc/research/session-based-remote-attestation.pdf 
> 
> 
>> A new version of I-D,

---

From: Anders Rundgren <[email-masked]>
Date: Wed, 8 Jul 2020 16:13:50 +0200

Hi Henk,

> of Claims collected over time - in one piece of evidence.

It is possible that you can characterize session-based remote attestations
like that but at least in my case the goal is different because it is only
about creating a secure session with an entity that has an attested quality.
The protected API is subsequently used for executing arbitrary secure
operations that for some reasons must be performed in a specific sequence.

This is pretty much a carbon copy of smart card provisioning where a session
is created based on an embedded key which indirectly provides attestation
(the card must be known).  The difference is that session-based remote
attestation does not presume a explicit knowledge of each trusted container.
The rollback feature is another enhancement.

It's not a big deal w.r.t. to the I-D, but it might be worth knowing anyway :)

Regards,
Anders