Robert Ferner’s contemporaries regarded him as among the very best senior cryptanalysts of the 1930s and 1940s. He had expertise in cryptanalysis, cryptography, and machine applications, and he was a dynamic leader. Ferner made major contributions to Allied cryptanalytic successes and improved America’s secure communications as well.
 
In 1936, Ferner became the first Junior Cryptanalyst hired by William Friedman since 1930 and worked with Frank Rowlett on Japanese diplomatic encryption machines. Ferner co-led the successful PURPLE project, a Japanese source that provided the Allies firsthand insights into the Third Reich as well as Japan.
 
Working with Rowlett and Albert Small, he pushed existing machine technology to its limits, solving another important Japanese diplomatic encryption system that William Friedman had deemed “impregnable.” Rowlett later noted that while Small excelled at generating ideas, Ferner made those concepts happen.
 
Ferner was an essential player against Germany’s Enigma and a prime contributor to Allied ability to read high-level German diplomatic traffic. He taught others about machine cryptanalysis, which was a cutting-edge skill at the time.
 
In 1943, he worked with British counterparts at Bletchley Park, deepening our cryptanalytic understanding. He later took charge of the Signal Security Agency’s new Research section within the General Cryptanalysis organization, leading it for the rest of the war.
 
Ferner left cryptologic service in 1948, largely due to health issues, but was called back briefly in 1952 to consult on a top-tier cryptanalytic problem. A senior leader called Ferner “the one person most apt to help us along to success on this problem.”