Re: [Last-Call] Last Call: <draft-knodel-e2ee-definition-07.txt> (Definition of End-to-end Encryption) to Informational RFC

John Levine <johnl@taugh.com> Wed, 12 October 2022 21:58 UTC

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From: John Levine <johnl@taugh.com>
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Subject: Re: [Last-Call] Last Call: <draft-knodel-e2ee-definition-07.txt> (Definition of End-to-end Encryption) to Informational RFC
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 [[ sigh, unhelpful text editor ]]

It appears that John Levine  <johnl@taugh.com> said:
>It appears that Brian E Carpenter  <brian.e.carpenter@gmail.com> said:
>>Hi,
>>
>>I assume this draft has been discussed widely in the Security Area, to
>>have reached last call, but I don't follow discussions there, so I'm
>>sorry if my comments are repetitive.
>>
>>> These dimensions taken as a whole comprise a generally comprehensible picture of consensus at the IETF as to what is end-to-end encryption,
>>
>>I'm not sure that we have any real consensus about this. I guess this
>>last call will tell us.
>
>I read the draft in detail and I have no idea whether webmail could be considered E2E encrypted.

I'm not looking for the answers to these questions, but for guidelines that would let us
come up with consistent answers.

Imagine we have webmail, encrypted connection between server and browser, mail encrypted with PGP or S/MIME.

If the mail is encrypted and decrypted on the server, so the server is part of the endpoint, is that E2E?

I have a mail account on a server on which I personally control the hardware and software, one at Protonmail,
one at Gmail.  Are the answers the same?

Or assume the encryption is in the browser or phone app.  Does the key management matter for E2E?
How about if the key is stored on the server, but the server promises not to use it, only to
provide it to the user's browser?  (You can check their 150,000 lines of code on Github to see
whether they actually do this.)

I realize this may seem somewhat nitpicky but if we're going to say end to end, we really need
a clear understanding of what "end" implies or requires.

R's,
John