NOVA Online (click here for NOVA home)
Decoding Nazi Secrets
Site Map

Comments from William's Team and Jim Gillogly
Back to Hall of Fame

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.

Crack the Ciphers | Send a Coded Message | A Simple Cipher
Are Web Transactions Safe? | Mind of a Codebreaker | How the Enigma Works
Resources | Teacher's Guide | Transcript | Site Map | Decoding Nazi Secrets Home

Editor's Picks | Previous Sites | Join Us/E-mail | TV/Web Schedule
About NOVA | Teachers | Site Map | Shop | Jobs | Search | To print
PBS Online | NOVA Online | WGBH

© | Updated November 2000

Support provided by

For new content
visit the redesigned
NOVA site