Subject: [nemo] RRH security draft

From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Fri, 30 Jul 2004 19:34:30 +0200

Hi Fan:

Thanks a lot for this work. I believe that there's a lot to say and a
lot that can be done for RRH security.

I must say that in our initial spec, we did have a subentry in the RRH
for MRs to sign the RRH till himself, as I understand that you propose.
We dropped it because we thought that the hop by hop checking of
topological correctness did provide a same level of protection. You must
think deeper about the handling of RH 2, as we already discussed that on
this list about draft-na-nemo-nested-path-info-00.txt: a MR will only
forward a RRH DOWN the tree. So loops are impossible. Also, an attacker
within the tree must send topologically correct packets (and source
packet from himself), so the attack always backfires on itself since the
MR above adds that address to the RRH. As a result, some of the attacks
you mention can actually NOT take place, though heave drooping is quite
feasible. I hope we can meet and discuss that. 

The other reason not to add the signature inside the RRH was that we
wanted a clean standard RH, easy to reverse. So we thought that the
signature -if one is wanted- should be outside the RRH. As you have
realized already:

- Entries in the RRH do not have to be addresses. The MR that writes an
entry is the only user for it.
- A MR is allowed to fully modify a RRH as long as it is able to restore
the right RH2 on the way back (but for entry 0). In particular, a MR may
transform the source address that he adds to the RRH using some
reversible crypto and a private key. 
- Prefixes advertised in the clear by a MR for other MRs to visit may
not be global prefixes. The MR may keep it global MNP for trusted (L2
authenticated) users and forge the prefix on the fly, renewing it every
so often, for the visitors. As a result, the CareOf are not global but
who cares. Only the MR that forged and exposed the prefix needs to route
on it. This preserves the privacy of the visited MR the way RFC 3041
preserves the privacy of the visitor.

So you see there's quite a lot of cool stuff we can do :)

Pascal

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf
Of Fan Zhao
> Sent: samedi 17 juillet 2004 00:56
> To: [email-masked]
> Subject: [nemo] new draft submitted
> 
> 
> Hello,
> 
> We have submitted a new draft on the security analysis and mechanisms
> of RRH, a proposed route optimization solution. Your comments are
> appreciated.
> 
>
http://www.ietf.org/internet-drafts/draft-zhao-nemo-rrh-security-00.txt
> 
> Abstract: In this draft, we begin with an extensive security analysis
> on a NEMO RO proposal, RRH, and then propose effective security
> mechanisms to resist those new threats introduced by the RRH header in
> the nested mobile network.
> 
> Thanks.
> 
> fan

---

From: "Fan Zhao" <[email-masked]>
Date: Fri, 30 Jul 2004 16:12:37 -0700 (PDT)

Dear Pascal,

Thank you very much for your insightful comments.
I have to admit that my original draft is very 
preliminary and immature. RRH is a very interesitng 
solution. Recently I rethink about some RRH security 
issues and general questions about RO, 
some of which you have already pointed out.
The document is quite long so I send it as an attachment. 
Please correct me if there are some errors. 
Look forward to meet you in SD.

Sincerely,
fan