Subject: [MOBILE-IP] Challenge Response issues

From: Patrice Calhoun <[email-masked]>
Date: Mon, 20 Dec 1999 11:02:59 -0800

All,

Some comments were received some time back, and it seems like Charlie and
I missed them. The issue that was raised was that it would be nice to
enable the Mobile Node to receive the challenge from the Foreign Agent without
having to constantly listen for Advertisements.

Of course, the first time that the Mobile Node connects to the network, it
will need a challenge value, which can be used. The subsequent registrations
shouldn't require that the Mobile Node listen for advertisements.

I believe that the conclusion that we came up with was that the Foreign Agent
could include a new challenge in the Registration Reply, which the Mobile
Node needed to include in the subsequent registration. Further, should the
Mobile Node move to a new service area, the challenge could be authenticated
via the binding update.

We are proposing to include this new text in a separate section entitled
"optimized approach".

Does anyone have any issues with the above proposal?

PatC

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From: Yoshiyuki Tsuda <[email-masked]>
Date: Tue, 21 Dec 1999 14:16:23 +0900

Hello, Pat:

>> Does anyone have any issues with the above proposal?

 For an MN's implementor, this will make much easier to implement the
 Challenge/Response mechanisms on MNs.  I'd like to confirm the following
 two more things:

 1) The challenge value in the Registration Reply is the same one in the
    previous Advertisement ?

 2) For backward compatibility, the following scenario may work fine:
        - If a challenge value is included in the Registration Reply,
          an MN should use the value in the next Registration Request.
        - If not, use the challenge value in the previous Advertisement.
    My question is your proposal is an approach or an additional requirement ?

Cheers.
-Yoshi