Re: Problems with implementation - DoS attacks possible

On Tue, 21 Jan 2003, Naohiro Fukuda wrote:

[...]

> (2) The collector handles that if the ICMP traceback message in the buffer-1
>      is not valid as a result of the authentication, flushing the message
>      or move it to another buffer-2, second.
>
> (3) Finally, the buffer-1 keeps only valid ICMP traceback message.

But the problem remains. The collector can't authenticate the message
right after the message is retrived. It must *wait* for the proper key to
be disclosured by the remote router/host/whatever. It will take minutes,
hours or maybe days(?).

So I think your proposition isn't quite suitable for this.


>
> I think the problem is how to keep the speed of authentication.

Yes, but collector *can't* speed up the authentication process. Look
above.


>    i)   Increase the size of buffer-1

Assuming I have 622 Mbps speed and I'm flooded with ICMP Traceback
messages. The time beetwen key change is one hour. Imagine how big
buffer-1 must be...


>    ii)  Accelarate the process of authentication

But in proposed authentication scheme the process can't be accelerated by
collector.

>    iii) Configure the lifetime of the key much longer

I rather hoped it will be much shorter :)


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Tomasz Grabowski  (0-91)4494234
Akademickie Centrum Informatyki
mailto:[email protected]