Re: [TLS] Working Group Last Call for draft-ietf-tls-downgrade-scsv-00

[Bodo Moeller <[e-mail]>]

Martin Rex <[e-mail]>:

> Bodo Moeller wrote:
>


> > (As an aside, if latency is the utmost concern, you don't strictly have
> to
> > try protocol versions in sequence -- you could do multiple connections in
> > parallel.
>


> Ouch?
>
> When using (EC)DHE cipher suites, then is the costly operation for the
> server not already triggered by ClientHello?  I think it would be a bad
> idea
> for *good* clients to perform multiple parallel connections to a server
> that force the server through PK-crypto, because that hits the server
> hard and makes it much more difficult for the server to distinguish
> good and bad clients in order to perform self-defense when the server
> is suffering from high load.


That's a good point, so multiple parallel connections probably aren't a
useful suggestion. (At least with (EC)DHE enabled.)

Of course, since this is about fallback retries, it would only affect
version-intolerant servers; maybe we shouldn't have too much sympathy with
those :-)

Bodo