John Stracke wrote: > > David J. Aronson wrote: > > >Now, suppose you salt the plaintext with rarer characters, so as to > >flatten out the distribution. > > I believe compression has the same effect, actually--compression uses > fewer bits for common characters, and the result is that the > distribution of bytes is flatter, and harder to attack. Come to think of it, that's even better than the salting I was proposing, as it (usually) isn't restricted to printable chars. So, let's go with that approach. Say you take the plaintext, zip it, then encrypt it. The question remains, given that the frequency distribution is fairly even, how does a cryptanalysis program know when it's got it right? (If "they" know you've used a specific publicly available compression program, they can look for its "signature" at the start, but let's ignore that for now....) -- David J. Aronson, Software Engineer for hire in Philadelphia area Resume, and other details, online at: http://dja2001.home.att.net Looking for work[ers] in Philly? See the Yahoo group PhillyJobs.