Subject: [nemo] RE: RRH security draft

From: "Fan Zhao" <[email-masked]>
Date: Mon, 2 Aug 2004 11:58:43 -0700 (PDT)

Dear Pascal,

Some comments on the folowing text.
1. This may not work in NEMO basic support. It will also prevent
using HA in the security mechanism for RRH. Also MR cannot advertise 
such globally unroutable prefix to MNN/LFN.

2. This also brings out the authorization issues.
what prefix is MR authorized to advertise? What happens
if two different MRs advertise the same prefixes?
 
fan   

> - 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.

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From: "Pascal Thubert \(pthubert\)" <[email-masked]>
Date: Mon, 2 Aug 2004 23:35:22 +0200

Hi Fan,

Thanks a lot for your interest

> 
> Some comments on the following text.

The forged MNPs are not advertised to the HA. They only work within an
RRH, and are only present on that link, for a short period of time.

> if two different MRs advertise the same prefixes?

The MR does not have to be globally authorized; it owns a link and toys
with it. The careof used in the RRH will never be the real source or
destination of a packet in the Internet, but always end up in a routing
header; the only trick is DHAAD. You have to implement a null RRH in
DHAAD messages that is reversed by the HA. This is part of the RRH
support and this is how we override the deadlock problem of the HA
attached to its own MR.

The model I have in mind for this is a link served by a MR (like each MR
has an AP). If you want to use that technique with more then one router,
you have a chance out of 2^61 that they forge the same. If they are
administered together, there's a way to include an short ID as part of
the 61 bits.