SolNET suffers a client bug

Nelson Minar (nelson@media.mit.edu)
Sat, 24 May 1997 12:22:22 -0400


Yesterday this announcement was posted to the SolNET mailing list:

Hi!

We've found an ugly bug in the _32bit_ bitslice clients.

As a result we've removed the clients from the web-page and FTP.
New clients without the 32-bit bitslice code will be released shortly.
This will require everybody to upgrade their clients since we have
to shut out all broken 1.11 clients.

Sorry for this screwup...

Regrads,
Fredrik Lindgren
SolNET DES Team

Since the announcement their keyrate has dropped from their recent
2000 MKeys/sec to 738 Mkeys/sec. (We're about 3600 MKeys/sec). Their
stats are worth a look - especially the big drop in the "blocks over
last 24 hours" graph.

It's worth taking a step back and learning from SolNET's recent
mishap. Is anyone on this list actively following SolNET's
development? What exactly was the bug? Can someone comment on their
quality control versus ours?

Did their keyrate have to go to 0 when they invalidated 1.11 clients.
What happened to all the (presumably non-broken) clients older than
1.11? Surely not everyone had upgraded from versions before 1.11? Were
they invalidated as well? Something to remember when designing
protocols - make it possible to obsolete particular versions, not just
"all versions older than X".

The costs of a bug in this type of computation are very high.

I don't want this or my earlier email comparing keyrates to sound like
I'm denegrating SolNET. They are doing an excellent job of cracking
DES. Our efforts are compatible, any competition between deschall and
SolNET should be entirely friendly.

SolNET should be commended for their organization and openness. They
have great mailing list archives, including an open development list.
They are giving out source code for their clients (albeit with a small
piece missing - you can't actually use the client to run on their
keyservers). Making inforomation available makes it much easier to
understand what is going on when a problem is discovered.