Subject: RE: [mobile-ip] Re: mobile-ip] RFC2002bis

From: [email-masked]
Date: Mon, 13 Aug 2001 16:54:21 -0500

Hi,

>> 
>> The working group chairs recently asked the working group,
>> by way of the mailing list, whether this incompatible
>> change would be acceptable.  The discussion was quite
>> limited, somewhat to my surprise.  This has been taken
>> as evidence that going with HMAC_MD5 is more-or-less
>> O.K.  Thus, it has been decided to go ahead with the
>> change.  On the other hand, it is conceivable that not
>> all interested parties have been notified of the possible
>> change, or have had time to reply.  If there are dissenters
>> to this change, now would be the time to express that
>> opinion.
>
>A quick question...when this was discussed on the mailing list last
>month, Kent and Gopal raised the issue of making MD5 also a MUST
>in RFC2002bis.  Discussion followed whether MD5 should be a MUST
>or a SHOULD for backwards compatibility...with the understanding that 
>HMAC_MD5 would be a MUST.  So, is the idea now not to even mention this

>use of MD5?  Please clarify.
>

The intent is to have HMAC-MD5 as the MUST for the authentication
algorithm. But MD5 will still be mentioned in the updated I-D.

>Thanks,
>Madhavi 

-Basavaraj

---

From: "Madhavi W. Chandra" <[email-masked]>
Date: Mon, 13 Aug 2001 18:04:08 -0400

> algorithm. But MD5 will still be mentioned in the updated I-D.

OK...but, mentioned HOW?  MUST or SHOULD?  The issue is that 
even though IESG advised on HMAC_MD5 as default, we need to ensure
backwards compatibility.  And I am still unclear on the ramifications
that Charlie outlined.  

Bottom line...breaking backwards compatibility is not acceptable or 
advisable, especially since there are MIP deployments out there.

Thanks,
Madhavi

---

From: Pat Calhoun <[email-masked]>
Date: Mon, 13 Aug 2001 15:16:31 -0700

> backwards compatibility.  And I am still unclear on the ramifications

As a SHOULD

> advisable, especially since there are MIP deployments out there.

But wouldn't it be irresponsible for us to tell folks to use something
that is known to be cryptographically weak? Do we really want another
WEP fiasco?

As I've mentioned before, the fact that is a SHOULD will lead people to
add a switch to allow admins to turn it on/off. That's all we want.
People that care, and want to make money, will support both modes.

Further, shipping products based on a proposed standard has always been
risky, since things can change when moving to Draft Standard (and believe
me, I've been on the receiving side more than once).

PatC