[Ufmrg] Re: [Seat] Re: Comments on formal analysis of relay attacks in intra-handshake attestation (CVE-2026-33697)

[Markus Rudy <[e-mail]>]

Hi Mark,

Thanks for sharing details about your work! Did you already share a proposal with the list? I would be interested in reading it, but can’t find it right now.

Cheers, Markus

From: Mark Novak <[e-mail]>
Date: Wednesday, 8. July 2026 at 18:39
To: Steve <[e-mail]>; Songbo Bu <[e-mail]>
Cc: Muhammad Usama Sardar <[e-mail]>; Nathanael Ritz <[e-mail]>; [e-mail] <[e-mail]>; [e-mail] <[e-mail]>
Subject: [Seat] Re: Comments on formal analysis of relay attacks in intra-handshake attestation (CVE-2026-33697)

Humbly adding my 2c to this discussion.

TLS protocol can remain unmodified if we separate the credential acquisition flow from credential usage in TLS. The Trustworthy Workload Identity SIG at the Confidential Computing Consortium has been working on just such a proposal. We have defined several mechanisms by which a workload, after performing Remote Attestation, can obtain a certificate to use with TLS. This approach allows a client and a server end of a TLS channel to be upgraded to Remote Attestation independent of each other, which is an important factor in unlocking deployment.

Our proposed mechanism does not suffer from the attacks mentioned in The Register articles. We have performed extensive threat modeling to make sure of that.

I am looking forward to discussing this in Vienna with all interested parties. Please engage with me in person or over email.

________________________________
From: Steve <[e-mail]>
Sent: Monday, July 6, 2026 7:57 AM
To: Songbo Bu <[e-mail]>
Cc: Muhammad Usama Sardar <[e-mail]>; Nathanael Ritz <[e-mail]>; [e-mail] <[e-mail]>; [e-mail] <[e-mail]>
Subject: [Seat] Re: Comments on formal analysis of relay attacks in intra-handshake attestation (CVE-2026-33697)

Dear all,

I am Research Analyst at Cloud Security Alliance (CSA-GCR).

Because of highly severe attacks, the intra-handshake.fail paper deserves close attention from the SEAT WG, UFMRG and the related research community. >From a Cloud Security Alliance community and cloud-security industry perspective, I strongly support bringing the paper and its supporting open-source code into the WG/RG discussion.
Cloud and confidential-computing deployments rely on attestation mechanisms that can be implemented, audited, and operated at scale. In this setting, a protocol extension that adds intra-handshake attestation behavior affects more than message syntax. It affects implementation assurance, conformance testing, incident response, certification, and enterprise risk acceptance.

The paper is therefore important industry input because it connects a concrete protocol-design question with formal analysis, relay-attack risk, and production implementation impact. Its treatment of binding mechanisms gives cloud providers, enterprise relying parties, security vendors, and governance teams a sharper basis for judging whether a proposed attestation transport path delivers security value proportionate to its operational complexity.

I strongly support using the Intra-handshake.fail paper and code as a reference point for further SEAT and UFMRG discussion, and I encourage review by WG participants, UFMRG experts, confidential-computing implementers, and cloud-security stakeholders.

Best regards,
Steve Luo
Research Analyst, Cloud Security Alliance (CSA-GCR)

Songbo Bu <[e-mail]<mailto:[e-mail]>> 于2026年7月6日周一 22:18写道：
Hi Usama, Slava, Jean-Marie, all,

Based on my participation in the related research discussions, I appreciate sharing Intra-handshake.fail paper and code with the WG/RG and strongly support using them as important technical input for the ongoing SEAT discussion.

The paper and code is valuable because it makes the discussion more property-driven. In particular, I think the WG should explicitly examine what security property a hybrid intra-handshake plus post-handshake attestation design can satisfy that post-handshake attestation alone cannot satisfy. This question is independent of any particular specification proposal, and it is important for evaluating whether additional intra-handshake complexity is technically justified.

I also support the paper’s narrower focus on intra-handshake attestation. Keeping the analysis scoped in this way avoids conflating different attestation models and allows the WG/RG to reason more precisely about binding mechanisms, relay attacks, and the relationship between Evidence and the TLS connection.

>From WG charter perspective, the paper is useful because it gives the community a concrete object to review, challenge, reproduce, and improve. This is especially important where formal models, protocol state-machine changes, and production implementations intersect.

It helps bring the standards community and formal methods researchers closer to share experience and ideas and provides UFMRG a concrete methodology for protocol analysis of AI agents.

For these reasons, I strongly support sharing this paper and code with the WG/RG and encourage review from SEAT WG participants and UFMRG formal-methods experts.

Best regards,
Songbo Bu
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