Re: [quicwg/base-drafts] Keep PN out of AEAD (#1578)

MikkelFJ <notifications@github.com> Sun, 29 July 2018 06:54 UTC

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Subject: Re: [quicwg/base-drafts] Keep PN out of AEAD (#1578)
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Based on discussion on the mailing list there are two issues to be aware of:

1. There is no clear text packet number length and this makes parallel operations less effective
2. A verified tag does not lead to a unique packet

The first issue can be resolved by keeping the length in clear text. The second issue can be resolved by either including the packet number length field in AEAD or by requiring the packet number length to be the shortet possible.

It is not clear if making the PN length visible would cause problems, but even encrypted the length can be learned after transmitting a few modified packets and observing if the packet gets accepted.

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