Re: SOI QUESTIONS: 2.3 Perfect forward secrecy (PFS)

[Ran Canetti <canetti@watson.ibm.com>]

Not necessarily. In JFK each party locally tunes its own PFS interval (from full
session-by-session PFS to no PFS at all), independently of the other side,
and without need for negotiation. (You can mandate that a party reveals its 
PFS policy to the peer, so that the peer will be able to make its respective 
policy decisions. But this is not necessary for interoperability.)

The same can be done with IKEv2, with the exception of the question 
whether the phase 2 exchange should support PFS. This seems to require
negotiation. (Please correct me if I'm wrong here.)

Ran


> From: "Scott Fanning" <sfanning@cisco.com>
> 
> As for PFS, if its there, it has to be negotiated. I would prefer that it be
> optional so that the widest possible platforms can support IKE/IPsec (CPU
> constraints, memory etc).
>