Re: draft-nordmark-multi6-threats-01.txt

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

On 12 jun 2004, at 18:22, Brian E Carpenter wrote:

> > What does make sense is to look at how the ability to cause 
> > redirection
> > has an impact on I, C, and A.

> And we certainly should not attempt to solve at network or transport
> level security issues that can only actually be solved at applications
> level, where the network and all its characteristics like multihoming
> are just viewed as a cloud anyway. If Santa Claus lets an elf use his
> computer, that is not our problem.

Unfortunately, some of these issues can't be solved in higher layers if 
lower layers are vulnerable. An example of this is an attack on TCP 
when TLS is in use. Since TLS sits on top of TCP, it can't improve on 
availability (in the presence of an attack) over regular TCP. It can 
only guarantee the integrity and confidentiality of communication that 
actually makes it through. Alternatively, IPsec rejects falsified 
packets before TCP sees them so it also improves availability.