Re: key change for TCP-MD5

[Jared Mauch <jared () puck nether net>]

On Tue, Jun 20, 2006 at 05:18:20PM -0700, Randy Bush wrote:
> > > The added cost for CPU-bound systems is that they have to try
> > > (potentially) multiple keys before getting the **right** key
> > > but in real life this can be easily mitigated by having a rating
> > > system on the key based on the frequency of success.
> >
> > This mitigates the effect of authenticating valid packets. However,
> > this does not appear to help at all in terms of minimizing the DOS
> > effect of an intentional DoS attack that uses authenticated packets
> > (with the processing time required to check the keys the intended
> > damage of the attack).
>
> gstm

        this doesn't help if the vendor can't implement it
correctly and does the md5 calc before checking the ttl :(

        - jared

-- 
Jared Mauch  | pgp key available via finger from jared () puck nether net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.