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Methods for the Solution of Ciphers

Publisher: Riverbank Laboratories

Subject: Cryptology

Riverbank Laboratories is a privately owned research facility located in Geneva, Illinois. In the early 20th century, Colonel George Fabyan, the founder and long-time director of Riverbank, began hiring specialists to conduct research in a variety of fields including acoustics, genetics, medicine, and cryptology. William F. Friedman arrived at Riverbank Laboratories in September 1915 to serve as the director for the Department of Genetics.

Shortly after William F. Friedman began working at Riverbank, he was asked to assist the Department of Cryptography with an investigation of the authorship of the works of Shakespeare by photographing text from Elizabethan books. This work was Friedman’s first introduction to the field of cryptography as well as to his future wife Elizebeth Smith, who had been hired to work on the Shakespearean authorship question in the summer of 1916. William F. Friedman began studying the theory and practice of cryptography while continuing to investigate the authorship of Shakespeare. Shortly thereafter, he was transferred to the Department of Cryptography where he began his lifelong study of codes and ciphers.

The United States’ entry into the First World War shifted the Department Of Cryptography’s focus to deciphering codes for the United States government as well as training recruits of the Army Intelligence Corps. While at Riverbank, William Freidman produced several publications that sought to establish the principles of cryptography on a mathematical foundation. The publications are collectively known as “The Riverbank Publications” and include several historically significant writings including “A Method of Reconstructing the Primary Alphabet from a Single One of the Series of Secondary Alphabets” (No. 15) and “The Index of Coincidence and Its Applications in Cryptography” (No. 22). William and Elizebeth left Riverbank and moved to Washington in late 1920.


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Methods for the Solution of Ciphers


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