Re: [quicwg/base-drafts] Timing side-channel on key updates (#2792)

Kazuho Oku <notifications@github.com> Mon, 17 June 2019 06:24 UTC

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Subject: Re: [quicwg/base-drafts] Timing side-channel on key updates (#2792)
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@MikeBishop That certainly reduces the information being potentially exposed to the attacker every one bit per key update.

But no less than that for example when an attacker injects two packets slightly more frequent than every 3 PTO, with the only difference between the two packets being the value of the KEY_PHASE bit. In such an attack scenario, the attacker can tell which of the two packets caused the calculation of the updated key for every key update.

Admittedly, the leak is tiny; but I am not sure if it is tiny enough that we can ignore.

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