Re: Messages lost on sci.crypt ?

Kristian Gjøsteen wrote:
> Francois Grieu <fgrieu@francenet.fr> wrote:
>
>>On the Usenet servers of my two competing ISPs (free aka proxad,
>>noos aka lyonnaise communication), all sci.crypt traffic
>
>>from Sep 24, 2005 to Oct 22, 2005 seems gone.
>
>>Google groups seems to have trouble too
>>http://groups.google.com/group/sci.crypt
>>
>>The problem does not seem to affect nearby sci.* groups
>>
>>Any idea of what is going on ?
>
> The same thing happened in July. At the time, I think it was said
> that somebody is forging cancel messages to the group. ISPs that
> accept cancel messages drop all the traffic. Some ISPs do not accept
> cancel messages (because they are easy to forge), and therefore do
> not see this.

   This fits the Internet security heuristic "Everything that can be
abused will be abused."

> This is very annoying. In order to inject a bit of cryptographical
> discussion again, here's a proposal:
>
> How do we protect against such attacks? What if every message
> includes a commitment to a secret (say a hash of a random string)?
> The newsreader records the secret for every message it posts. When
> you need to cancel a message, you include the secret in the cancel
> message. Every news server verifies that the secret matches the
> commitment.
> [snip]

   Not bad, but is it more likely to be adopted than, say, hashcash?

--Mike Amling
Received on Mon Oct 24 02:08:09 2005