This is a new version of the DES encryption program.  It is eight times
smaller than the first version, and about 10 percent slower.  One minor
bug fix was made, but this version is still compatible with the old
version.

The old version was based on 8-bit and 12-bit wide look-up tables.  The
new versions uses 4-bit and 6-bit ones.  In addition, the S and P boxes
could now be combined, and a number of the look-up tables were either
all zeros or contained numbers in the range of "unsigned short int".
All in all, the program became even smaller and much of the lost speed
was bought back.

This program runs correctly on the VAX/780.  It should compile on PDP-11
and 3B-20 computers, but it may not run correctly!  I have not tried it.

I strongly advise that people bringing this code up do not modify the
code (like the "numbersoup" or "canofbugs" constants).  Many sites run
this program, and it would be nice to keep it standard so people can
exchange encrypted data.
