> I was mulling over some old emails about randomly-generated > numbers and realized that if I had an imperfectly random > source (something less than 100% unpredictable), that > compressing the output would compress it to the point where > it was nearly so. Would there be any reason to choose one > algorithm over another for this application?
I see where you're coming from, but take an imperfectly random source and apply a deterministic function to it, and if I recall correctly, you still have a imperfectly random output. It would be better to use something like Von Neumann's unbiasing algorithm (or any of the newer improvements) to strip out the non-randomness. > I recall talking to a CS prof once who said that LZW > compression was "optimal", which seemed and still seems > really odd to me because optimal compression would generate a > null output file. So surely he meant asymptotically optimal, > or e-close to optimal, or something like that... anyone know? He probably meant optimal in the information theoretic sense. If that was the case, then no, optimal compression will not yield a null-length output -- it will give you the minimum length output that could represent your input from among all inputs. Or maybe he didn't ;) Regards, Jeremy Hansen, MS, CISSP Director of Security RAIR Technologies Any views or opinions presented in this email are solely those of the author and do not necessarily represent those of RAIR Technologies, Inc. The individual author will be personally liable for any damages or other liability arising from this email. RAIR Technologies * Brookfield, WI * 262-780-6000 --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
