I was pretty sure I was getting somewhere with this approach, but I ended up at 54 characters, just like chipmunk.
sub crypto{ ($_,$a,%h,$h)=@_;s/./chr($h{$&}||=vec$a,$h++,8)/gse;$_ }

In reply to Re: (Golf) Cryptographer's Tool #1 by tadman
in thread (Golf) Cryptographer's Tool #1 by Masem

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":