[OTR-dev] session termination

[Ian Goldberg]

On Mon, Apr 30, 2007 at 03:46:08AM +0300, Marti Raudsepp wrote:
> On 4/29/07, Ian Goldberg <ian at cypherpunks.ca> wrote:
> >One problem with dropping to FINISHED when you notice the other side
> >goes offline is that that notification is unauthenticated.  An adversary
> >can trivially spoof a "Bob went offline" message, and it would be
> >unfortunate if that caused Alice to forget her session keys.
> 
> But does it really matter? When the attacker already has the
> capability of spoofing messages on behalf of the IM network, then
> surely they could also just disrupt (deny) communication between the
> parties -- which is effectively the same as far as I can tell.

Yes, an attacker can always cause a DoS by making the network stop
working.  But allowing him to easily force Alice to forget her session
keys seems worse to me.

   - Ian