Re: [TLS] [SUSPECTED URL!]Re: Requiring that (EC)DHE public values be fresh

[Colm MacCárthaigh <[e-mail]>]

On Mon, Jan 2, 2017 at 11:43 AM, Yoav Nir <[e-mail]> wrote:

> I’m assuming that the server generates private keys and saves them to a
> file along with the time period that they were used, and another machine in
> a different part of the network records traffic. It’s not so much that the
> clocks need to be accurate, as that they need to be synchronized, and there
> will still be some misalignment because of (variable) latency.
>
> I guess we are making guesses about systems that haven’t been written yet.
>

Logging the actual session keys is a feature that some Enterprise
appliances have today, and that would continue to work in all scenarios
(sadly). It's not that much data to log (far less than a request log for
example). In that case it's often left unindexed and simple tools like grep
are used for ad-hoc decryption requests,which are typically rare enough not
to merit anything better.

For simplicities sake, I'd prefer single-use ECDHE, rather than
time-delimited. Mostly because it's simpler to implement. The current
generation of IOT and other small embedded systems are already at the point
where they can do this kind of thing.

-- 
Colm