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From: camilo ayerbe <cayerbe@gmail.com>
Date: Thu, 30 Jul 2026 13:35:17 +0200
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To: Songbo Bu <bluedognull@gmail.com>
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Subject: =?utf-8?q?=5BSeat=5D_Re=3A_Comments_on_formal_analysis_of_relay_attacks_in_a?=
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Hi all,

I'd like to add one point from an independent angle, and be clear about
what it does and doesn't claim. For disclosure, I'm a co-author of TRIP
<https://datatracker.ietf.org/doc/draft-ayerbe-trip-protocol/>, which is
post-handshake, so I have a stake here.

The CVE stands on its own =E2=80=94 the relay on the self-asserted-key bind=
ers is
real, and the response to it was right. From the timeline shared
<https://github.com/muhammad-usama-sardar/intra-handshake.fail#detailed-vul=
nerability-disclosure-timeline>,
I see that all the relevant stakeholders have acknowledged the relay
attacks:

   -

   Cocos AI created the security advisory
   <https://github.com/ultravioletrs/cocos/security/advisories/GHSA-vfgg-mv=
xx-mgg7>
   and acknowledged the formal analysis
   -

   CCC Intra-handshake attestation implementation
   <https://github.com/ccc-attestation/attested-tls-poc> has been
declared vulnerable
   to relay attacks,
   <https://github.com/CCC-Attestation/attested-tls-poc/pull/58>and the
   repository has been archived.
   -

   Vulnerable intra-handshake draft draft-fossati-tls-attestation
   <https://datatracker.ietf.org/doc/draft-fossati-tls-attestation/10/> has
   been withdrawn by authors.
   -

   Edgeless Systems has created the security advisory
   <https://github.com/edgelesssys/contrast/security/advisories/GHSA-hjgc-j=
c5v-fw7h>
   and acknowledged the formal analysis.



On the question the thread is actually asking =E2=80=94whether a hybrid int=
ra+post
design gives a security property post-handshake alone cannot =E2=80=94 I mo=
deled
the specified =C2=A75.1.1 (CA-backed TIK) of
draft-fossati-seat-early-attestation-05 binder independently and landed
where Usama and all others in the thread have: I couldn't find a property
achievable in intra-handshake that a post-handshake step right after secure
channel establishment couldn't also achieve. So I'm not offering a
counter-example =E2=80=94 if anything, my look supports the "no separation"
reading, and it leaves the open question where Songbo has put it: what does
the intra-handshake version establish that post alone doesn't? If there is
no such property, the complexity of intra-handshake is unnecessary, which
is itself a security problem that I would like to avoid for my draft. I'd
also agree the symbolic security analysis doesn't settle the computational
questions raised here =E2=80=94 proof-of-possession for a key placed in rep=
ort
data, and cryptographic key-separation for reusing TLS-derived secrets both
need more than symbolic security analysis. I'd leave those open.

The dimension I'd add is *continuity*, as an architectural requirement
rather than a formal property. An intra-handshake binder attests once, at
setup; for use cases where the peer's measured state can change over the
life of the connection, that single attestation goes stale, and only
post-handshake =E2=80=94 repeated or interval =E2=80=94 attestation keeps i=
t fresh. This is
the case TRIP is built around, and a one-shot intra-handshake binder
structurally can't provide it. I raise it because it points the same way as
the thread: post-handshake is the load-bearing mechanism, and for these use
cases it isn't optional.


Thanks, Camilo


On Thu, Jul 30, 2026 at 11:48=E2=80=AFAM Songbo Bu <bluedognull@gmail.com> =
wrote:

> Hi all,
>
> I agree with the clarifications in Usama's message. The question is
> not whether a modified construction can satisfy selected correlation
> properties under its own assumptions. My question was whether a hybrid
> intra- and post-handshake design establishes a specific security
> property that post-handshake attestation alone cannot establish.
>
> The public artifact separates three correlation goals: Evidence with
> the DH shared secret (G1), the client handshake traffic key (G2), and
> the client application traffic key (G3). It shows that its proposed
> intra-handshake construction establishes G1 and G2 but not G3. The
> artifact does not model a hybrid design against a post-handshake-only
> baseline, so it does not demonstrate a hybrid-over-post separation.
>
> For that reason, I think a claimed counter-example should state:
>
> 1. the exact property satisfied by hybrid but not post-only;
> 2. the identical adversary, trust, and deployment assumptions under
> which both are compared;
> 3. the exact statement in Section 9 that the result contradicts; and
> 4. the endpoint events and correspondence query used to establish the
> separation.
>
> Without that separation, changing the construction may still produce a
> useful design, but it does not answer the question I posed. It also
> leaves the additional intra-handshake machinery=E2=80=94Evidence availabi=
lity
> during the handshake, interaction with transcript and key state, new
> failure paths, and implementation burden=E2=80=94without a demonstrated
> security benefit over post-handshake attestation alone.
>
> I also agree that two questions should be evaluated separately from
> symbolic equality. Placing an infrastructure public key or identity in
> signed report data does not by itself prove possession of the
> corresponding private key. Reusing TLS-derived traffic keys for
> another purpose also needs an explicit key-separation and
> computational-security justification. These questions are not settled
> merely because a symbolic model can express an equality.
>
> This does not rule out operational reasons for a hybrid design. It
> asks that operational motivation be separated from the claimed
> security property, and that the latter be stated in a form that can be
> formally verified. ProVerif code is never wired up in real
> implementations.
>
> On Tue, 28 Jul 2026 15:37:02 -0600, Nathanael Ritz <nathanritz@gmail.com>
> wrote:
> > Top posting. It appears I have been asked to set aside falsifiable
> formal analysis effort or to suggest that such work is itself
> unfalsifiable. While that may or may not be true, I believe this thread h=
as
> truly run its course.
> >
> > Sincerely,
> >
> > Nathanael
> >
> > On Tue, 28 Jul 2026 at 14:37, Muhammad Usama Sardar <
> muhammad_usama.sardar@tu-dresden.de> wrote:
> >
> > Hi Nathanael,
> >
> > Markus kindly clarified what he would like to see in more detail.
> > Could you please do the same to help keep this discussion more
> > focused? Here is my understanding of the points where you
> > disagree:
> >
> > - While the paper [6] claims it 'may not be possible' to achieve
> > level 3 binding in intra-handshake attestation, you believe it
> > is possible. Setting aside what you model and prove is correct
> > or not, I don't see how this contradicts the claim 'may not be
> > possible' in the paper.
> >
> > - We haven't yet seen a property that the hybrid construction
>
> > (intra- + post-handshake attestation) can satisfy, but
> > post-handshake attestation alone cannot satisfy, unless
> > you are implicitly implying that level-3 binding cannot be
> > achieved by post-handshake attestation. Please clarify
> > explicitly.
> >
> > Is there something I have missed? As mentioned before to Markus,
> > I believe it is much more organized to have them answered in
> > detailed technical report. So more important than the discussion
> > below is the correction/addition/edits in above statements.
> >
> > Also, I believe it will be more constructive to respond point by
> > point to [5] where you disagree, so we can do further working to
> > share with the WG/RG.
> >
> > We will then work on it and share with the WG/RG.
> >
> > On 28.07.26 20:51, Nathanael Ritz
> > wrote:
> >
> > On Tue, 28 Jul 2026 at
> > 10:00, Muhammad Usama Sardar <muhammad_usama.sardar@tu-dresden.de>
> > wrote:
> >
> > This does not address any of the questions in [5]
> > where your working was shown to be not correct, and
> > these inaccuracies still remain here too.
> >
> > [NR}: I disagree, but the authors are welcome to cite
> > my work and my words directly in relationship to any
> > questions that are, in their opinion, left unanswered so
> > that I can address them directly rather than guessing.
> >
> > For example, our responses to your #2 in [5].
> >
> > For clarity, nothing has changed in the key schedule
> > of TLS 1.3 for quite long time (I think draft-20 which
> > became RFC8446). Saying that RFC9846 is "new work" for
> > key schedule is almost surely wrong. Maybe Ekr can
> > confirm.
> >
> > [NR]: If it is being stated that I am suggesting
> > RFC9846 includes 'new work for key schedule', please quote
> > me directly, as I am currently unclear to what context and
> > statements are being referenced to right now.
> >
> > Thanks for clarifying. 'non-conformant Key Schedule' and then
> > mention of RFC 9846 =C2=A77.5 was unclear for #2 in [5]; it has stayed
> > the same for pretty much a decade. We believe that both points in
> > your #2 about key schedule are not valid and we justified it
> > technically in [5], to which we have seen no response.
> >
> > Best regards,
> >
> > Usama, Slava, and Jean-Marie
> >
> > [5]
> https://mailarchive.ietf.org/arch/msg/seat/dKVqaL8RJSQLonIEmtzrDYEXEAU/
> >
> > [6]
> https://www.researchgate.net/publication/408219182_Intra-handshakefail_CV=
E-2026-33697_High-severity_CVE_in_Attested_TLS
>
> _______________________________________________
> Seat mailing list -- seat@ietf.org
> To unsubscribe send an email to seat-leave@ietf.org
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<div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div class=3D"gmail_defa=
ult" style=3D"font-family:verdana,sans-serif;font-size:small;color:rgb(0,0,=
0)"><span id=3D"m_85791172376000554gmail-docs-internal-guid-d101e635-7fff-1=
0f8-396f-7f4c4d836a04"><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:=
0pt;margin-bottom:0pt"><span style=3D"background-color:transparent;font-fam=
ily:Arial,sans-serif;font-size:11pt;white-space:pre-wrap">Hi all,</span></p=
><br><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:=
0pt"><span style=3D"font-size:11pt;font-family:Arial,sans-serif;background-=
color:transparent;font-variant:normal;vertical-align:baseline;white-space:p=
re-wrap">I&#39;d like to add one point from an independent angle, and be cl=
ear about what it does and doesn&#39;t claim. For disclosure, I&#39;m a co-=
author of </span><a href=3D"https://datatracker.ietf.org/doc/draft-ayerbe-t=
rip-protocol/" style=3D"text-decoration:none" target=3D"_blank"><span style=
=3D"font-size:11pt;font-family:Arial,sans-serif;background-color:transparen=
t;font-variant:normal;text-decoration:underline;vertical-align:baseline;whi=
te-space:pre-wrap">TRIP</span></a><span style=3D"font-size:11pt;font-family=
:Arial,sans-serif;background-color:transparent;font-variant:normal;vertical=
-align:baseline;white-space:pre-wrap">, which is post-handshake, so I have =
a stake here.</span></p><br><p dir=3D"ltr" style=3D"line-height:1.38;margin=
-top:0pt;margin-bottom:0pt"><span style=3D"font-size:11pt;font-family:Arial=
,sans-serif;background-color:transparent;font-variant:normal;vertical-align=
:baseline;white-space:pre-wrap">The CVE stands on its own =E2=80=94 the rel=
ay on the self-asserted-key binders is real, and the response to it was rig=
ht. From the </span><a href=3D"https://github.com/muhammad-usama-sardar/int=
ra-handshake.fail#detailed-vulnerability-disclosure-timeline" style=3D"text=
-decoration:none" target=3D"_blank"><span style=3D"font-size:11pt;font-fami=
ly:Arial,sans-serif;background-color:transparent;font-variant:normal;text-d=
ecoration:underline;vertical-align:baseline;white-space:pre-wrap">timeline =
shared</span></a><span style=3D"font-size:11pt;font-family:Arial,sans-serif=
;background-color:transparent;font-variant:normal;vertical-align:baseline;w=
hite-space:pre-wrap">, I see that all the relevant stakeholders have acknow=
ledged the relay attacks:=C2=A0</span></p><ul style=3D"margin-top:0px;margi=
n-bottom:0px"><li dir=3D"ltr" style=3D"list-style-type:disc;font-size:11pt;=
font-family:Arial,sans-serif;color:rgb(29,28,29);background-color:transpare=
nt;font-variant:normal;vertical-align:baseline;white-space:pre-wrap;margin-=
left:18pt"><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:5pt;margin-b=
ottom:0pt" role=3D"presentation"><span style=3D"font-size:11pt;color:rgb(0,=
0,0);background-color:transparent;font-variant:normal;vertical-align:baseli=
ne;white-space:pre-wrap">Cocos AI created the </span><a href=3D"https://git=
hub.com/ultravioletrs/cocos/security/advisories/GHSA-vfgg-mvxx-mgg7" style=
=3D"text-decoration:none" target=3D"_blank"><span style=3D"font-size:11pt;b=
ackground-color:transparent;font-variant:normal;text-decoration:underline;v=
ertical-align:baseline;white-space:pre-wrap">security advisory</span></a><s=
pan style=3D"font-size:11pt;color:rgb(0,0,0);background-color:transparent;f=
ont-variant:normal;vertical-align:baseline;white-space:pre-wrap"> and ackno=
wledged the formal analysis</span></p></li><li dir=3D"ltr" style=3D"list-st=
yle-type:disc;font-size:11pt;font-family:Arial,sans-serif;color:rgb(29,28,2=
9);background-color:transparent;font-variant:normal;vertical-align:baseline=
;white-space:pre-wrap;margin-left:18pt"><p dir=3D"ltr" style=3D"line-height=
:1.38;margin-top:0pt;margin-bottom:0pt" role=3D"presentation"><a href=3D"ht=
tps://github.com/ccc-attestation/attested-tls-poc" style=3D"text-decoration=
:none" target=3D"_blank"><span style=3D"font-size:11pt;background-color:tra=
nsparent;font-variant:normal;text-decoration:underline;vertical-align:basel=
ine;white-space:pre-wrap">CCC Intra-handshake attestation implementation</s=
pan></a><span style=3D"font-size:11pt;background-color:transparent;font-var=
iant:normal;vertical-align:baseline;white-space:pre-wrap"> has been declare=
d</span><a href=3D"https://github.com/CCC-Attestation/attested-tls-poc/pull=
/58" style=3D"text-decoration:none" target=3D"_blank"><span style=3D"font-s=
ize:11pt;color:rgb(29,28,29);background-color:transparent;font-variant:norm=
al;vertical-align:baseline;white-space:pre-wrap"> </span><span style=3D"fon=
t-size:11pt;color:rgb(18,100,163);background-color:transparent;font-variant=
:normal;vertical-align:baseline;white-space:pre-wrap">vulnerable to relay a=
ttacks, </span></a><span style=3D"font-size:11pt;background-color:transpare=
nt;font-variant:normal;vertical-align:baseline;white-space:pre-wrap">and th=
e repository has been archived.</span></p></li><li dir=3D"ltr" style=3D"lis=
t-style-type:disc;font-size:11pt;font-family:Arial,sans-serif;color:rgb(29,=
28,29);background-color:transparent;font-variant:normal;vertical-align:base=
line;white-space:pre-wrap;margin-left:18pt"><p dir=3D"ltr" style=3D"line-he=
ight:1.38;margin-top:0pt;margin-bottom:0pt" role=3D"presentation"><span sty=
le=3D"font-size:11pt;background-color:transparent;font-variant:normal;verti=
cal-align:baseline;white-space:pre-wrap">Vulnerable intra-handshake draft</=
span><a href=3D"https://datatracker.ietf.org/doc/draft-fossati-tls-attestat=
ion/10/" style=3D"text-decoration:none" target=3D"_blank"><span style=3D"fo=
nt-size:11pt;color:rgb(29,28,29);background-color:transparent;font-variant:=
normal;vertical-align:baseline;white-space:pre-wrap"> </span><span style=3D=
"font-size:11pt;color:rgb(18,100,163);background-color:transparent;font-var=
iant:normal;vertical-align:baseline;white-space:pre-wrap">draft-fossati-tls=
-attestation</span></a><span style=3D"font-size:11pt;background-color:trans=
parent;font-variant:normal;vertical-align:baseline;white-space:pre-wrap"> h=
as been withdrawn by authors.</span></p></li><li dir=3D"ltr" style=3D"list-=
style-type:disc;font-size:11pt;font-family:Arial,sans-serif;color:rgb(29,28=
,29);background-color:transparent;font-variant:normal;vertical-align:baseli=
ne;white-space:pre-wrap;margin-left:18pt"><p dir=3D"ltr" style=3D"line-heig=
ht:1.38;margin-top:0pt;margin-bottom:5pt" role=3D"presentation"><span style=
=3D"font-size:11pt;background-color:transparent;font-variant:normal;vertica=
l-align:baseline;white-space:pre-wrap">Edgeless Systems has created the</sp=
an><a href=3D"https://github.com/edgelesssys/contrast/security/advisories/G=
HSA-hjgc-jc5v-fw7h" style=3D"text-decoration:none" target=3D"_blank"><span =
style=3D"font-size:11pt;color:rgb(29,28,29);background-color:transparent;fo=
nt-variant:normal;vertical-align:baseline;white-space:pre-wrap"> </span><sp=
an style=3D"font-size:11pt;color:rgb(18,100,163);background-color:transpare=
nt;font-variant:normal;vertical-align:baseline;white-space:pre-wrap">securi=
ty advisory</span></a><span style=3D"font-size:11pt;background-color:transp=
arent;font-variant:normal;vertical-align:baseline;white-space:pre-wrap"> an=
d acknowledged the formal analysis.</span></p></li></ul><br><br><p dir=3D"l=
tr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom:0pt"><span style=
=3D"font-size:11pt;font-family:Arial,sans-serif;background-color:transparen=
t;font-variant:normal;vertical-align:baseline;white-space:pre-wrap">On the =
question the thread is actually asking =E2=80=94whether a hybrid intra+post=
 design gives a security property post-handshake alone cannot =E2=80=94 I m=
odeled the specified =C2=A75.1.1 (CA-backed TIK) of draft-fossati-seat-earl=
y-attestation-05 binder independently and landed where Usama and all others=
 in the thread have: I couldn&#39;t find a property achievable in intra-han=
dshake that a post-handshake step right after secure channel establishment =
couldn&#39;t also achieve. So I&#39;m not offering a counter-example =E2=80=
=94 if anything, my look supports the &quot;no separation&quot; reading, an=
d it leaves the open question where Songbo has put it: what does the intra-=
handshake version establish that post alone doesn&#39;t? If there is no suc=
h property, the complexity of intra-handshake is unnecessary, which is itse=
lf a security problem that I would like to avoid for my draft. I&#39;d also=
 agree the symbolic security analysis doesn&#39;t settle the computational =
questions raised here =E2=80=94 proof-of-possession for a key placed in rep=
ort data, and cryptographic key-separation for reusing TLS-derived secrets =
both need more than symbolic security analysis. I&#39;d leave those open.</=
span></p><br><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin=
-bottom:0pt"><span style=3D"font-size:11pt;font-family:Arial,sans-serif;bac=
kground-color:transparent;font-variant:normal;vertical-align:baseline;white=
-space:pre-wrap">The dimension I&#39;d add is <b>continuity</b>, as an arch=
itectural requirement rather than a formal property. An intra-handshake bin=
der attests once, at setup; for use cases where the peer&#39;s measured sta=
te can change over the life of the connection, that single attestation goes=
 stale, and only post-handshake =E2=80=94 repeated or interval =E2=80=94 at=
testation keeps it fresh. This is the case TRIP is built around, and a one-=
shot intra-handshake binder structurally can&#39;t provide it. I raise it b=
ecause it points the same way as the thread: post-handshake is the load-bea=
ring mechanism, and for these use cases it isn&#39;t optional.</span></p><b=
r><br><p dir=3D"ltr" style=3D"line-height:1.38;margin-top:0pt;margin-bottom=
:0pt"><span style=3D"font-size:11pt;font-family:Arial,sans-serif;background=
-color:transparent;font-variant:normal;vertical-align:baseline;white-space:=
pre-wrap">Thanks, Camilo</span></p><br></span></div></div><br><div class=3D=
"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Thu, Jul 30, 2026 at=
 11:48=E2=80=AFAM Songbo Bu &lt;<a href=3D"mailto:bluedognull@gmail.com" ta=
rget=3D"_blank">bluedognull@gmail.com</a>&gt; wrote:<br></div><blockquote c=
lass=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px soli=
d rgb(204,204,204);padding-left:1ex">Hi all,<br>
<br>
I agree with the clarifications in Usama&#39;s message. The question is<br>
not whether a modified construction can satisfy selected correlation<br>
properties under its own assumptions. My question was whether a hybrid<br>
intra- and post-handshake design establishes a specific security<br>
property that post-handshake attestation alone cannot establish.<br>
<br>
The public artifact separates three correlation goals: Evidence with<br>
the DH shared secret (G1), the client handshake traffic key (G2), and<br>
the client application traffic key (G3). It shows that its proposed<br>
intra-handshake construction establishes G1 and G2 but not G3. The<br>
artifact does not model a hybrid design against a post-handshake-only<br>
baseline, so it does not demonstrate a hybrid-over-post separation.<br>
<br>
For that reason, I think a claimed counter-example should state:<br>
<br>
1. the exact property satisfied by hybrid but not post-only;<br>
2. the identical adversary, trust, and deployment assumptions under<br>
which both are compared;<br>
3. the exact statement in Section 9 that the result contradicts; and<br>
4. the endpoint events and correspondence query used to establish the<br>
separation.<br>
<br>
Without that separation, changing the construction may still produce a<br>
useful design, but it does not answer the question I posed. It also<br>
leaves the additional intra-handshake machinery=E2=80=94Evidence availabili=
ty<br>
during the handshake, interaction with transcript and key state, new<br>
failure paths, and implementation burden=E2=80=94without a demonstrated<br>
security benefit over post-handshake attestation alone.<br>
<br>
I also agree that two questions should be evaluated separately from<br>
symbolic equality. Placing an infrastructure public key or identity in<br>
signed report data does not by itself prove possession of the<br>
corresponding private key. Reusing TLS-derived traffic keys for<br>
another purpose also needs an explicit key-separation and<br>
computational-security justification. These questions are not settled<br>
merely because a symbolic model can express an equality.<br>
<br>
This does not rule out operational reasons for a hybrid design. It<br>
asks that operational motivation be separated from the claimed<br>
security property, and that the latter be stated in a form that can be<br>
formally verified. ProVerif code is never wired up in real<br>
implementations.<br>
<br>
On Tue, 28 Jul 2026 15:37:02 -0600, Nathanael Ritz &lt;<a href=3D"mailto:na=
thanritz@gmail.com" target=3D"_blank">nathanritz@gmail.com</a>&gt; wrote:<b=
r>
&gt; Top posting. It appears I have been asked to set aside falsifiable for=
mal analysis effort or to suggest that such work is itself unfalsifiable. W=
hile that may or may not be true, I believe this thread has truly run its c=
ourse.<br>
&gt;<br>
&gt; Sincerely,<br>
&gt;<br>
&gt; Nathanael<br>
&gt;<br>
&gt; On Tue, 28 Jul 2026 at 14:37, Muhammad Usama Sardar &lt;<a href=3D"mai=
lto:muhammad_usama.sardar@tu-dresden.de" target=3D"_blank">muhammad_usama.s=
ardar@tu-dresden.de</a>&gt; wrote:<br>
&gt;<br>
&gt; Hi Nathanael,<br>
&gt;<br>
&gt; Markus kindly clarified what he would like to see in more detail.<br>
&gt; Could you please do the same to help keep this discussion more<br>
&gt; focused? Here is my understanding of the points where you<br>
&gt; disagree:<br>
&gt;<br>
&gt; - While the paper [6] claims it &#39;may not be possible&#39; to achie=
ve<br>
&gt; level 3 binding in intra-handshake attestation, you believe it<br>
&gt; is possible. Setting aside what you model and prove is correct<br>
&gt; or not, I don&#39;t see how this contradicts the claim &#39;may not be=
<br>
&gt; possible&#39; in the paper.<br>
&gt;<br>
&gt; - We haven&#39;t yet seen a property that the hybrid construction<br>
<br>
&gt; (intra- + post-handshake attestation) can satisfy, but<br>
&gt; post-handshake attestation alone cannot satisfy, unless<br>
&gt; you are implicitly implying that level-3 binding cannot be<br>
&gt; achieved by post-handshake attestation. Please clarify<br>
&gt; explicitly.<br>
&gt;<br>
&gt; Is there something I have missed? As mentioned before to Markus,<br>
&gt; I believe it is much more organized to have them answered in<br>
&gt; detailed technical report. So more important than the discussion<br>
&gt; below is the correction/addition/edits in above statements.<br>
&gt;<br>
&gt; Also, I believe it will be more constructive to respond point by<br>
&gt; point to [5] where you disagree, so we can do further working to<br>
&gt; share with the WG/RG.<br>
&gt;<br>
&gt; We will then work on it and share with the WG/RG.<br>
&gt;<br>
&gt; On 28.07.26 20:51, Nathanael Ritz<br>
&gt; wrote:<br>
&gt;<br>
&gt; On Tue, 28 Jul 2026 at<br>
&gt; 10:00, Muhammad Usama Sardar &lt;<a href=3D"mailto:muhammad_usama.sard=
ar@tu-dresden.de" target=3D"_blank">muhammad_usama.sardar@tu-dresden.de</a>=
&gt;<br>
&gt; wrote:<br>
&gt;<br>
&gt; This does not address any of the questions in [5]<br>
&gt; where your working was shown to be not correct, and<br>
&gt; these inaccuracies still remain here too.<br>
&gt;<br>
&gt; [NR}: I disagree, but the authors are welcome to cite<br>
&gt; my work and my words directly in relationship to any<br>
&gt; questions that are, in their opinion, left unanswered so<br>
&gt; that I can address them directly rather than guessing.<br>
&gt;<br>
&gt; For example, our responses to your #2 in [5].<br>
&gt;<br>
&gt; For clarity, nothing has changed in the key schedule<br>
&gt; of TLS 1.3 for quite long time (I think draft-20 which<br>
&gt; became RFC8446). Saying that RFC9846 is &quot;new work&quot; for<br>
&gt; key schedule is almost surely wrong. Maybe Ekr can<br>
&gt; confirm.<br>
&gt;<br>
&gt; [NR]: If it is being stated that I am suggesting<br>
&gt; RFC9846 includes &#39;new work for key schedule&#39;, please quote<br>
&gt; me directly, as I am currently unclear to what context and<br>
&gt; statements are being referenced to right now.<br>
&gt;<br>
&gt; Thanks for clarifying. &#39;non-conformant Key Schedule&#39; and then<=
br>
&gt; mention of RFC 9846 =C2=A77.5 was unclear for #2 in [5]; it has stayed=
<br>
&gt; the same for pretty much a decade. We believe that both points in<br>
&gt; your #2 about key schedule are not valid and we justified it<br>
&gt; technically in [5], to which we have seen no response.<br>
&gt;<br>
&gt; Best regards,<br>
&gt;<br>
&gt; Usama, Slava, and Jean-Marie<br>
&gt;<br>
&gt; [5] <a href=3D"https://mailarchive.ietf.org/arch/msg/seat/dKVqaL8RJSQL=
onIEmtzrDYEXEAU/" rel=3D"noreferrer" target=3D"_blank">https://mailarchive.=
ietf.org/arch/msg/seat/dKVqaL8RJSQLonIEmtzrDYEXEAU/</a><br>
&gt;<br>
&gt; [6] <a href=3D"https://www.researchgate.net/publication/408219182_Intr=
a-handshakefail_CVE-2026-33697_High-severity_CVE_in_Attested_TLS" rel=3D"no=
referrer" target=3D"_blank">https://www.researchgate.net/publication/408219=
182_Intra-handshakefail_CVE-2026-33697_High-severity_CVE_in_Attested_TLS</a=
><br>
<br>
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</blockquote></div></div>
</div>

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