Cryptologic Bytes

Cryptanalytic Challenges

On this page, we will periodically post cryptanalytic challenges, including "tools" of the trade. All visitors are invited to provide any solutions to the challenges or information on how a tool was used by cryptographers. A summary of information received will be posted with each article. Unless noted otherwise in the article, submit your comments to, with a subject line of: Cryptanalytic Challenge.

  • Follow this interesting exchange regarding the potential meaning behind symbols on the stained glass windows of a WWII Memorial Chapel on the grounds of Lake Junaluska in the western mountains of North Carolina.

  • Can you help us determine who, how, when, and where this device was actually used by cryptographers, radio operators or other NSA/DoD personnel. The DoD transfer form attached to the unit described it as a "National Security Telephone."

  • Do you know who, how, when, and where this WWI manual coding device was used by cryptographers and/or radio operators? Read the comments submitted by other Web site visitors.

  • This 10 Point Divider (sometimes called an 11 Point Divider) came from the estate of a now deceased former cryptographer. Can you help us to determine how it was used by cryptographers? Read comments submitted by other Web site visitors.


Check out the Cryptologic Bytes Archives for a wide variety of articles on all topics related to cryptology, codes and ciphers, related publications, Museums, and more.