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[TLS] Re: Key Hierarchy TLS 1.3 RFC8446(bis)

Muhammad Usama Sardar <muhammad_usama.sardar@tu-dresden.de> Mon, 06 October 2025 23:35 UTC

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From: Muhammad Usama Sardar <muhammad_usama.sardar@tu-dresden.de>
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Subject: [TLS] Re: Key Hierarchy TLS 1.3 RFC8446(bis)
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I have consolidated my current analysis of the TLS 1.3 key schedule in 
this pre-print [0]. I have organized it as one section (1.3) independent 
of ProVerif and the other section (1.4) maps to it such that those with 
no knowledge of ProVerif can also see how intuitive the mapping is.

Some of the PSK part is still a mystery to me. That needs a careful review.

I welcome any thoughts or comments on how it can be improved, such that 
it can serve as reference formal artifacts for TLS 1.3 key schedule.

I started work on provision of functionality of ExtendedKeyUpdate in my 
model but that is subject to precise clarifications [1]. In my 
understanding, ProVerif alone will be insufficient. I think it 
additionally needs a computational analysis, but I have no experience 
with that.

-Usama

[0] 
https://www.researchgate.net/publication/396245726_Perspicuity_of_Attestation_Mechanisms_in_Confidential_Computing_Validation_of_TLS_13_Key_Schedule

[1] https://github.com/tlswg/tls-key-update/issues/59

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