Re: New multi6 draft: WIMP

[Iljitsch van Beijnum <iljitsch@muada.com>]

On 28-jan-04, at 16:57, Jukka Ylitalo wrote:

> We have submitted a new multi6 draft to I-D directory. The draft 
> defines a Weak Identifier Multihoming Protocol (WIMP), and we wrote it 
> in order to see how opportunistic/weak authentication methods could be 
> used to sove the multi6 problem.

Ok. This is basically a secure negotiation mechanism. All other aspects 
of multihoming are only addressed fleetingly, if at all.

When a host wants to negotiate new addresses, some info is split into n 
pieces and sent to n addresses. What happens if less than the full set 
of n addresses is reachable?

I believe there is a problem with the gradual release of secret 
information (such as hash chains) when a man in the middle can trick 
both sides to become desynchronized such that side A has two messages 
in transit, messages M+1 and M+2, with an ealier message being M. M, 
M+1 and M+2 are protected using hashes X, X+1 and X+2, respectively. 
Side B can check whether message M+1 is authentic by taking X+1, 
performing a function over it and determining whether the result is 
equal to X. However, a man in the middle that already has X+2 could 
create X+1 and then use this value to create an authentic-looking 
message M+1. Or am I missing something?