eap Mailing List: Re: Proposed Resolution of Issue 361: Child Key Expiry

[Narayanan, Vidya (vidyan]

> 
> >In the above, are you talking about an EMSK compromise after expiry 
> >affecting any keys that may still be in use?
> 
> If the EMSK expires and the session is still in progress, 
> presumably the result is an EAP re-authentication which 
> results in new child keys.
> 
> >If so, I'm wondering how
> >viable that is - basically, the point that I'm not clear on 
> is this - 
> >if the EMSK is used to derive any keys that are handed out to other 
> >entities, depending on the purpose of the key, the EAP server may 
> >really have no control over that lifetime.
> 
> It can provide a maximum lifetime (Session-Timeout) to the 
> authenticator, requesting EAP re-authentication to occur when 
> the maximum lifetime expires.
> 
> The distinction we're making here is between maximum lifetime 
> (controlled by
> Session-Timeout) and deletion.  If the EMSK is deleted on the 
> peer or server, this doesn't cause child keys to be deleted.  
> However, expiry of the maximum lifetime does result in new child keys.
> 

Ok. The revised text for section 3.3 then looks good. 

Vidya