On Wed, Sep 26, 2007 at 09:58:12AM -0400, Jeff Lightner wrote:
> I also suggest the argument is flawed because it seems to imply that
> only the cksum is stored and no actual the data - it is original
> compressed data AND the cksum that result in the restore - not the cksum
> alone.

It's not that the actual data isn't stored, it's whether or not the
actual data is checked.  Some algorithms search through the hash space,
and if a hit comes up, they assume that the previously stored data is a
match without a comparison.

The original data must always be stored.  Even if it were possible to
run a hash algorithm in reverse quickly, there would be no way to
determine which of various possible input strings was the original.

-- 
Darren Dunham                                           ddunham AT taos DOT com
Senior Technical Consultant         TAOS            http://www.taos.com/
Got some Dr Pepper?                           San Francisco, CA bay area
         < This line left intentionally blank to confuse you. >
_______________________________________________
Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu