Minutes IETF115: scitt: Thu 09:30
minutes-115-scitt-202211100930-00

DRAFT SCITT Agenda, IETF 115, London, UK
Donnerstag, 10. November 2022
09:30 - 11:30 Thursday Session I

Note takers: Kay Williams, Steve Lasker

1. Welcome and Introduction (5 min): Chairs

   • [Roman Danyliw] Introduced new chairs Hannes Tschofenig and
     Jon Geater
   • [Hannes] will send out a doodle poll for regular SCITT
     meetings

2. Problem Statement / What Is SCITT (5 mins): Orie Steele (Transmute)

3. Software Supply Chain Uses Case (15min): Yogesh Deshpande (ARM)

4. Architecture (30 mins): Antoine (Microsoft)

   • Discussion on Overview Slide
   • [Dave Thaler] Terminology confusion verification, evidence
     have different meaning in RATS
   • [Antoine] Claim terminology is subject to change
     See Issue: Converge Claim and Statement #34
   • [David Thaler] It would be useful to draw comparisons to RATS
     specifications
   • [Henk Birkholz] If verifier looks into claims, then verifier
     is more like in RATS. Claim is used in a different way in RATS.
     Mapping from SCITT terminology to RATS will give a way to
     improve in the end.
   • [Yogesh Deshpande] Yes, there is some overlap in terms.
     Suggest these can co-exist as long as there is clear
     descriptions.
   • [Dan Drulta - ATT] Question 1: Is there a need for a forked
     verification process, Question 2: Who is the issuer, in the
     Log4J case, there are different issurers.
   • [Antoine] (notes nto captures)
   • [Henk] SCITT provides scalability and offline verifiability
   • [Elliot Lear] Incorporate claim in packaging. Important that
     trust anchos be in place so that trust is possible. Needs to be
     enough information so that viewer of receipt can contact the
     issuer.
   • [Antoine] Verification can happen offline
   • [Brendan Moran] In firmware case you probably don't want to
     deliver all claims to device. SCITT transparency service
     provides a standardized way to store claims.
   • [Mike Prorock] Software package fixed at some time. Being able
     to go back and have a record of what happned in time all in one
     place is valuable. Intersection of time and statements all in
     one place helps with this.
   • [Erik Nordmark] Want to track most recent version of software.
     What is scope, it could be balloon intonn something very big.
   • [Antoine] It could indeed baloon very big. Won't be a single
     transparency service for everyone. Also there will be simple
     notaries that will provide some claims. In summary, complexity
     of notaries in the wild.
   • [Wei Pan] Will Microsoft expose which employee wrote code on
     the transparency service.
   • [Antoine] Question is related to privacy. Should this
     information be released or not. In general, this is a choice of
     the notary. If you want to only partially release this
     information, you have control over information submitted to the
     registry, including access controls.
   • Discussion on Verification & Audit Slide
   • [Brendan] Is the auditor auditing the claim or the signing
     information only.
   • [Antoine] What type of audits are supported is an open
     question
   • [Orie] Three cases for audit - specific claim, set of claims,
     entire transparency registry (this last one would be very
     expensive)
   • Discussion on Security Goals Slide
   • [Dan Drula] (ATT) Issues are verifiers get replicated. How
     will inter-registry trust be implemented?
   • [Antoine] Important question and not easy. Will be addressed
     in Hackathon report
   • [Orie] Discussed inter-leger trust at Hackathon, slides and
     diagrams in Hackathon section of the deck
   • [Dave Thayler] please elaborate on ...
   • [Dave Thayler] definition of correct - same answer (correct or
     incorrect) to everyone.
   • [Jon Geater] you have to have registered your claims in the
     past, you can't selectively lie, cheat, etc. Whole system
     responsibility
   • [Diego Lopez] Transparent registry is not going to make
     additional checks because in that case the notary will become an
     issuer.
   • [Antoine] Accepting registry of a claim is a form of
     endorsement. Baseline is for registry to verify signature.
   • [Diego Lopez] Can an issuer say 'I received this and tested
     it'?
   • [Antoine] Yes
   • Summary
   • [Hannes] Call for adoption of architecture so that it can
     continue to be discussed on the mailining list. Use 'show of
     hands' tool.
   • [Hannes] Poll results - 36 for adopting, 3 against adopting

5. SCITT Receipts (15 min): Maik Riechert (Microsoft)

   • [Hannes] Any imemdiate feedback on the receipt?
   • [Carsten] (thumbs up)
   • [Hannes] Next steps - use case document needs to be rewritten
     and approved, architecture document needs updating (including
     terminology). After that, push forward to COSE receipts)
   • [Roman] First agree on what problem we want to solve, and then
     how to solve it (e.g. Receipt)

6. Hackathon Report (30 min): Henk Birkholz (Fraunhofer SIT) and Orie
   Steele (Transmute)

   Henk's Slides

   • [Brendan] Similar concept in SUIT
   • [Henk] Yes, but will need to be discussed in SCITT
   • [Michael Prorock] Affirm that some statements will be big.
     Also, notice conflict on terminology from slide to slide
   • [Henk] Will need to discuss in the working group, have a few
     good proposals for WG to discuss
   • [Michael Prorock] Example outside of software... in US, Food
     and Drug Agency (FDA) has specified content that must be
     provided. SCITT provides a mechanism for tracking and verifying

   Orie's Slides

   • [Erick Nordmark] FIPS not a great example
   • [Orie] (acknowledged)
   • [Mike Prorock] Did the topic of ?? come up
   • [Orie] Receipt 1 is there and can be given to anyone who
     needs. Did I answer question?
   • [Mike] No. Does author know who is requesting a claim.
   • [Antoine] Comment on idea that when you are consuming a
     receipt it is always downstream. Not always refer to depencency
     by value. Sometimes want to refer to claim by URI
   • [Orie] How do I find all receipts for a specific product (e.g.
     device driver)
   • [Yogesh/Orie] Who is using receipt is at the discretion of the
     people who hold the receipts.
   • [Carsten Bormann] Want to have choice. User does not have
     choice of which transparency service to use. In the end
     important for who system to have certain quality with regards to
     privacy. E.g. I will only work with transparency services that
     provide certain privacy guarantees.
   • [Orie] Discussion of registration policies, e.g. issuer, size
     of statement, etc. User can decide when service to submit data
     to.
   • [Carsten] Different actors may have different privacy needs.
     Can imagine transparency services that improve the guarantees of
     other transparency services (e.g. heighten privacy)
   • [Antoine] Once claim is issued there may be access control.
     Perfectly acceptable for same claim to be registered on multiple
     transparency services.
   • [Dan Druta] Like the way this is depicted. How will we
     implement in a SAAS model? You don't know what you are running
     on top of as a customer. I represent an operator. Risk
     management is an important thing. How do I mitigate risk -
     shutdown service, etc. Want to do things from the other way
     around.
   • [Orie] Yes - also want to support other direction. Start with
     final artifact and trace backwards. Make it easier to identify
     information that is relevant to risk assessment.
   • [Dan Druta] To be clear - from user and operator perspective
     want to know...
   • [Isaac Hepworth] want to know if policy changes how does that
     affect analysis of receipts
   • [Orie] discussion on need for communicating changes in policy.
     Provide a new receipt that notifies of policy changes.
   • [Isaac] Malicious operator of transparency service
   • [Orie] Multiple trees in transparency service. However,
     trusting transparency service operator to manage both trees
     appropriately. Might need to have multiple transparency
     services.
   • [Isaac] Timestamp integrity?
   • [Chris Inacio]If you don't trust transparency service 1, you
     resign? Time matters a lot. If you don't trust transparency
     service, then as an issuer you need to submit to multiple
     transparency services.
   • [Orie] if you submit to multiple transparency services then
     you will have different times at both services
   • [Henk] A transparency service is not a monolithic node.
     Discussions also under Confidential Compute Consortium (CCC),
     Remote Attestation Protocols (RATS). Didn't want to bring up
     complexity of timing in first session, but we are thinking about
     it.
   • [Antoine] Say a few words about policy and policy updates. As
     verifier want to understand policy. As issuer, may want to
     indicate what policies are applied, e.g. sequential claim.
     Declaration of policy that can be interpreted by verifiers. Also
     aspect of freshness which is important. If you are using a piece
     fo code, want to know you are using the latest version. As Orie
     mentioned, you can specialize types of receipts.
   • [Orie] One point on registration - each claim evaluated
     against registration policy of each service. Policies or aspects
     of policies can be shared across transparency services.
   • [Antoine] Also important to be able to audit that registration
     policies were enforces
   • [Yogesh] In confidential computing we talk about workload
     measurements and attestations. (to address Dan's earlier
     comment) Tho we have not explicitely put a slide that goes the
     other direction, we have not ignored that scenario.

7. AOB (Open Mic) & Next Steps (15 min): Chairs

   • [Dan] I like this work and think it will benefit companies
     like mine immensely. Didn't hear a word about SBOM. Perhaps that
     was implied. Acknowledge fact that there are already standards.
     May come out as we are decomposing standards into atomic
     components.
   • [Yogesh] Use case slide does mention SBOMs (SPDX, CycloneDX).
     What we are providing is on top of SBOM where we are providing
     transparency suggestion
   • [Wei Pan] Example specific content. Statement may say 'refer
     to this url'
   • [Orie/all] Yes this is allowed (and covered in hackathon
     content)

8. Wrap-up and Conclusion (5 min): Chairs