Distributed Brute Force Projects

From: foo (foo_at_foo.com)
Date: 05/29/04 

Date: Sat, 29 May 2004 00:25:11 +0100

There are several distributed brute force crypto projects currently
underway, MD5CRK and distributed.net to name a couple. Can anyone tell
me how these projects verify the information given to them by the
various distributed clients? What's to stop some attacker from
decompiling/disassembling the various client programs, finding out how
the program reports it's findings to the server, and re-implementing the
their own client which reports false information?

Many thanks in advance

regards,

foo