Friday, December 17, 2010

Callimahos and the Dundee Jar

There's a curious story on how a marmalade jar became a symbole of cryptanalytic skills within the National Security Agency (NSA). It all began in the late 1950's, when Lambros Demetrios Callimahos created the Intensive Study Program in General Cryptanalysis (ISPGC), also known as the CA-400 course.

It was the first extensive high-level course for experienced and senior cryptanalysts. Callimahos based his course on William Friedman's manual on Military Cryptanalysis. He revised and expanded Friedman's work into the new training manuals Military Cryptanalytics I and II and molded it into an extremely demanding course, unequaled in wide range of subjects and in dept.

The students rushed trough the Military Cryptanalytics manuals to continue with exercises in cryptanalysis of codes, ciphers, cipher machines and traffic analysis. While solving their crypto problems, they were assisted by aids who helped them to speed up their paper work. By doing so, Callimahos managed to reduce a most complex course from 12 to 4 month. Clearly not a course for wannabees that were still wet in the pants!

He composed many new examples and problems that the students had to solve. At the end of each course, the students had to solve the notorious Zendian Problem. The students received 375 encrypted military messages, intercepted from the fictional third world country Zendia. The messages were encrypted with various manual systems and cipher machines. Within two weeks, they had to break all exploitable message. It was the perfect opportunity to merge all their skills into one single fictional yet most difficult codebreaking operation. The exercise prepared them perfectly to tackle the real stuff.

The course was also the start of a tradition of gatherings for the graduates at a local restaurant. While making the reservation for a diner, Callimahos faced the problem that he could not disclose the real - secret - purpose of the group. He quickly devised the name Dundee Society by looking at a marmalade jar that served as a pencil holder at the CA-400 course. The Dundee Society was born! Since then, every graduate received a Dundee jar, which became a symbol of a truly extraordinary course for elite cryptanalysts. In 1977, Lambros Callimahos died much too soon, at the age of 66.

You can read the story of the Callimahos course (pdf) on the NSA website. More on the Cryptologic Almanac, as part 1 and part 2. In 2003, Callimahos was inducted in the NSA's Hall of Honor.

William Friedman's Military Cryptanalysis is also available in five parts  at the NSA website.

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