Subject: RE: [eap] Strawman -10/EMSK deletion requirement?

From: "Glen Zorn (gwz)" <[email-masked]>
Date: Thu, 9 Mar 2006 09:09:23 -0800

Jari Arkko <mailto:[email-masked]> supposedly scribbled:

> Glen Zorn (gwz) wrote:
> 
>> Joseph Salowey (jsalowey) <> supposedly scribbled:
>> 
>> 
>> 
>>> The EMSK is the root of all AMSKs, so a compromise of the EMSK
>>> compromises all AMSKs.  Therefore I would like to see the EMSK
>>> protected as much as possible.  Once the EMSK is securely deleted
>>> it cannot be compromised. 
>>> 
>>> 
>> 
>> OK, but is that not equally true of Jari's proposed AMSK_root_0
>> approach? 
>> 
>> 
> The problem is that since EMSK is the root, its compromise will lead
> to the compromise of all derived keys. This also holds locally for
> the AMSK_root_0 approach. That is, if AMSK_root_0 is compromised then
> any keys derived from that root are compromised (but not keys in
> other apps).    

I guess I'm just confused, then (not a first!).  I thought that the major problem was that it is basically impossible to no which (if any) _applications_ a person would choose to use during a session.  If that is accurate, I can't really see how the AMSK_root_0 approach solves the problem.  If that's not the problem, what is?

> --Jari

Hope this helps,

~gwz

Why is it that most of the world's problems can't be solved by simply
  listening to John Coltrane? -- Henry Gabriel
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From: Jari Arkko <[email-masked]>
Date: Thu, 09 Mar 2006 20:01:12 +0200

>I guess I'm just confused, then (not a first!).  I thought that the major problem was that it is basically impossible to no which (if any) _applications_ a person would choose to use during a sessio…
Oh. Maybe I was confused. AMSK_root_0 does not solve that
problem. It solves the problem that if your application requires
multiple keys (as in fast handoff to AP2, AP3, etc) then you still
only need one AMSK from the EMSK for the application. That
AMSK_root_0 can then be used to generate all the keys that
the application in question needs.

--Jari