David rote:
If so, then using the dictionary as the key seems bad---the compression dictionary is not designed to obscure the data, but to aid in compression. The dictionary might well be easy to guess. For example, some compression schemes use a Huffman coding on their dictionary. If so, one can guess that short pointers into the dictionary correspond to common plaintext strings. Using such a dictionary as an encryption system is security through obscurity.
Oh Heavens to Betsy, I was not trying to describe *crypto*, that might be regulated. Was describing a mechanism to comply with the new Scudderite laws concerning protecting the innocent from nasty sights. Figure it this way: can duplicate CD-Roms for a quarter. If a subscription costs $19.95/yr then who is going to bother with cloning it ? "controlled circulation" magazines would save postage. Web pages could be posted with nothing but pointers (don't tell me you have never sat waiting for a little red bar to reach the end) and assurance that only a specified audience could look at the pretty pictures (which compress the best of all 8*). Further, if the intent is to satisfy a law then would this not be a "good faith" attempt to do so ? Zippy's friends have decided what is not safe to be on the net in the clear but they have not said what it takes to protect the innocent while allowing consenting adults their freedom to communicate. If I want good crypto I just use PGP (and the Enclyptor makes it real easy). This is something completely different. Warmly, Padgett