G'day all.
dontspam-tzeruch(_at_)ceddec(_dot_)com writes:
It seems that most versions of PGPlib use some derivative of the zip
algorithm that offers different compression levels, e.g. gzip defaults to
6. PGP 5.0 defaults to 1. Is there any level that SHOULD be used?
6 (default) is much better than 1, but slower.
I don't see any a priori reason to recommend a specific compression
level since it doesn't affect decompression in any way, nor should it
affect security to any great degree (remember that actually performing
compression is only a MAY; its purpose is to speed up encryption and
decryption as well as to "randomise" the cleartext bit stream).
Recommending a level which implementations SHOULD use seems like overkill.
Also keep in mind that RFC1951 doesn't actually specify what a "level"
means even in its description of the reference implementation.
Cheers,
Andrew Bromage