Editing William F. Friedman (section)

== Initial work in cryptology ==
[[File:William and Elizebeth Friedman 1917.jpg|thumb|William and Elizebeth Friedman, recently married, at Riverbank in 1917]]
[[File:Riverbank Laboratories (Geneva, IL) 01.JPG|thumb|Riverbank Laboratories]]
Another of Fabyan's pet projects was research into secret messages which Sir [[Francis Bacon]] had allegedly hidden in various texts during the reigns of [[Elizabeth I of England|Elizabeth I]] and [[James I of England|James I]]. The research was carried out by [[Elizabeth Wells Gallup]]. She believed that she had discovered many such messages in the works of [[William Shakespeare]], and convinced herself that Bacon had written many, if not all, of [[William Shakespeare|Shakespeare]]'s works. Friedman had become something of an expert photographer while working on his other projects, and was asked to travel to England on several occasions to help Gallup photograph historical manuscripts during her research. He became fascinated with the work as he courted [[Elizebeth Friedman|Elizebeth Smith]], Gallup's assistant and an accomplished cryptographer. They married, and he soon became director of Riverbank's Department of Codes and Ciphers as well as its Department of Genetics. During this time, Friedman wrote a series of eight papers on cryptography, collectively known as the "[[Riverbank Publications]]", including the first description of the [[index of coincidence]], an important mathematical tool in cryptanalysis.<ref name="Fagone2017">{{cite book|author=Jason Fagone|title=The Woman Who Smashed Codes: A True Story of Love, Spies, and the Unlikely Heroine Who Outwitted America's Enemies|url=https://books.google.com/books?id=V00ODQAAQBAJ|year=2017|publisher=HarperCollins|isbn=978-0-06-243050-2}}</ref><ref name=kahn1967>{{cite book|last=Kahn|first=David|author-link=David Kahn (writer)|title=The Codebreakers: The Story of Secret Writing|year=1967|publisher=The Macmillan Company|location=New York|isbn=978-0-684-83130-5|title-link=The Codebreakers}}</ref>
{{rp|p. 374 ff}}

With the entry of the United States into [[World War I]], Fabyan offered the services of his Department of Codes and Ciphers to the government. No Federal department existed for this kind of work (although both the Army and Navy had had embryonic departments at various times), and soon Riverbank became the unofficial cryptographic center for the US Government. During this period, the Friedmans broke a code used by [[Germany|German]]-funded [[India]]n radicals in the US who planned to ship arms to [[India]] to gain independence from Britain.<ref name="Fagone2017" /> Analyzing the format of the messages, Riverbank realized that the code was based on a dictionary of some sort, a cryptographic technique common at the time. The Friedmans soon managed to decrypt most of the messages, but only long after the case had come to trial did the book itself come to light: a German-English dictionary published in 1880.
[[File:1924 detail, W. F. Friedman LCCN2016848773 (cropped).tif|left|thumb|W. F. Friedman in 1924]]