Comments from William's Team (John Hanson, William Rowden, and Tobin Stelling)
William used a computer script to find allowable positions for
RED PENGUIN FRENZY and then create possible Playfair squares. Each team member
then took a square and looked for possible words. The correct square was soon
evident; the team filled it in by guessing additional words. We would like to
thank sci.crypt for inspiration.
Comments from Jim Gillogly
William enlarged on his team's solution method in his Usenet postings in
the newsgroup sci.crypt. The program appears to do a very nice job of
automating the crib-dragging process mentioned by Martin Cope.
One can test for confirmations by finding repeated digraphs or reversed digraphs,
or for contradiction by finding repeated or reversed digraphs that do not match,
or single letters that do match between plaintext and ciphertext. Their exercise
also shows a technique that was important both at Bletchley Park and in modern
distributed cryptographic attacks: the Human Wave approach. Cryptanalysis
attacks can often be segmented into pieces that can be farmed out to others,
so that parallelism with very little overhead can be achieved.