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Re: key change for TCP-MD5

  • From: Jared Mauch
  • Date: Wed Jun 21 09:05:27 2006

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 [email protected]
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.