Many people have given me help and advice or have unknowingly contributed!

All those involved with Linux development in general and the loop device
in particular.

Bruce Schneier for the Blowfish algorithm.
Colin Plumb for some very helpful criticism.
Bob Jenkins for the whitening algorithm.
Panu Matilainen for the patches for ext2 loop labels.

And of course all of you have tried PPDD and fed back your comments.
