Related to ChaocipherThe
cryptologic literature makes references to Chaocipher-related
correspondences, spanning more than thirty years, between John
F. Byrne and William F. Friedman. These references include
Byrne's quotes in his autobiography "Silent Years", David Kahn's
descriptions in The Codebreakers, and numerous articles posted on The
Chaocipher Clearing House (TCCH) web site. Although known to a
select few, these
correspondences have never been publicly available.
Chaocipher Clearing House is proud to present a significant amount
of Chaocipher-related correspondences between John F.
Byrne, William F. Friedman, and others. It is our hope that
correspondences available will shed historical light on this
fascinating episode, and possibly lead to solving this, by now,
legendary cipher mystery.
owe a great debt of gratitude to several indefatigable cryptologic
researchers for unearthing these important correspondences.
(a) American Cryptogram
Association (ACA) member Wesley H. Horton (DRIVE-IN) was the
first to obtain copies of the 1922 and 1942 Friedman-Byrne
correspondence from the NSA in 1985. Horton made
available to interested ACA members.
founding editor of the ACA Computer Supplement, Mike Barlow,
sent copies of the 1922 and 1942 correspondence to any ACA member who
requested it. (Mike, who passed away in May 1990, was an
energetic member of the ACA. In 1986, after months of lobbying,
on his own, he single-handedly developed the Computer Supplement, and
was instrumental in interesting numerous ACA members in the Chaocipher.)
(c) In 1998, ACA member Jeffrey Hill (E. E.
REMINGTON) following leads
supplied by Mike Barlow, obtained copies of Friedman-Byrne material
from the George C. Marshall Research Foundation that yielded a
speech by Friedman made in response to Chapter 21 in Silent Years and
also copies of letters exchanged between Friedman and Byrne in 1957, as
well as the 1922 and 1942 correspondence already known.
In 2009, ACA member Hub Ratliff (HUB), a native of Austin, Texas, kindly agreed to visit the Harry
Ransom Center in Austin and thoroughly search through the entire folder
containing John F. Byrne's papers. This netted several unknown
correspondences (e.g., Byrne's original 29 January 1957 letter to
Friedman, Byrne's letters to Herbert O. Yardley challenging him to
solve the Chaocipher messages).
am particularly indebted to Jeff Hill for generously sharing the
information he had. Without Jeff's magnanimity these
correspondences would not have seen the light of day on TCCH.
addition I am most thankful to Hub Ratliff for finding the time in
his truly busy schedule to perform a sterling research job for me, albeit a fellow ACA
member but a hitherto unknown entity<g>.
correspondences, spanning the years 1922-1957, illuminate the
interaction between John F. Byrne and William F. Friedman in his
capacity as Head Cryptanalyst, Chief Signal Office. They have
been arranged in chronological order, allowing you to read and
experience the correspondences in the logical and progressive order
The following chronology is divided into five (5) different periods:
- 1922: Byrne's initial contact with Friedman and the Army Signal Corps.
- 1937-1938: Byrne's attempt to interest the U.S. Navy in his improved model
- 1942: Byrne contacts Friedman during World War II, after a 20 year hiatus, with the aim of submitting his machine
- 1954: Friedman delivers a talk about Byrne's "Silent Years"
Byrne contacts Friedman for the last time, demanding an explanation
from Friedman why Chaocipher was not being seriously considered
following table details a chronology of correspondences between John F.
Byrne and a number of persons. A link to a letter or
correspondence is provided when relevant. The sources include:
- The George
C. Marshall Research Foundation, William
F. Friedman Collection ("GCMRF")
Harry Ransom Center, The University of Texas at Austin ("HRC")
- The National Cryptologic Museum of the NSA ("NCM")
F. Byrne's autobiographical "Silent Years" ("SY").]
|1918||John F. Byrne discovers a novel cryptographic principle, leading to the invention of his Chaocipher.||SY: 264|
|1921||August 3||Colonel Parker Hitt||John F. Byrne||1||Hitt returns Chaocipher evaluation material, offers his initial opinion of the cipher system.||NCM|
|1922||March 7||Colonel Parker Hitt||John F. Byrne||Hitt declines to get personally involved in Chaocipher, offering to introduce Byrne to Major Frank Moorman.||SY:
travels to Washington, is introduced to Major Moorman and William F.
Friedman by Colonel Parker Hitt, demonstrates his first model.||SY: 275|
|1922||August 21||John F. Byrne||Major Frank Moorman||This letter is referred to in the following letter from Moorman (August 26)||SY: 276|
26||Major Frank Moorman||John F. Byrne||Major Moorman acknowledges Byrne's letter||SY:
7||William F. Friedman||John F. Byrne||2||Friedman
apologizes profusely for the damaged model returned to Byrne. He
also clarifies that this early model was not reliable, verifies that he
performed analysis, and requests a set of messages from Byrne.||GCMRF|
F. Byrne||Admiral Bowen||Tells Bowen about the availability of his system.||SY: 277|
J. M. Irish||John F. Byrne||Thanks Byrne for the opportunity to examine his system.||SY: 278|
F. Byrne||Captain J. M. Irish||Sends Captain Irish a copy of the booklet "Chaocipher - The Ultimate Elusion".||SY: 278-279|
J. M. Irish||John F. Byrne||Captain Irish lists possible stipulations should the Navy choose to adopt the system.||SY: 280|
conference, Washington, D.C.||SY: 279|
demonstration, Washington, D.C., Commanders Wagner and Tucker
|1942||March||John F. Byrne||G. M. Campbell||1||GCMRF|
3||John F. Byrne||William F. Friedman||2||GCMRF|
5 / 6 (?)||William F. Friedman||Lt. Hiser||1||GCMRF|
6||William F. Friedman||John F. Byrne||1||WFF's reply to Byrne was most probably drafted by Lt. Hiser.||GCMRF|
9||John F. Byrne||William F. Friedman||1||GCMRF|
16||William F. Friedman||John F. Byrne||1||GCMRF|
Friedman||2||Notes on a
railroad diner card about his proposed speech||GCMRF|
|1954||February 15||Helen Herbert
F. and Elizebeth Friedman||1||GCMRF|
|1954||March 2||Helen Herbert
F. and Elizebeth Friedman||1||GCMRF|
speech about John F. Byrne's "Silent Years"||GCMRF|
|1957||January 29||John F. Byrne||William F. Friedman||Byrne's initial letter to WFF in 1957
(inferred by WFF's reply on February 6)||HRC (on order)|
|1957||February 6||William F. Friedman||John F. Byrne||1||WFF's reply to Byrne's previous letter
(reproduced by permission of the Harry Ransom Center)||HRC|
17||John F. Byrne||William F. Friedman||1||GCMRF|
28||John F. Byrne||William F. Friedman||1||GCMRF|
3||William F. Friedman||John F. Byrne||1||GCMRF|
|1958||June 1||John F. Byrne||Herbert O. Yardley||HRC (on order)|
|1958||June 24||John F. Byrne||Herbert O. Yardley||HRC (on order)|
|1958||July 24||John F. Byrne||Herbert O. Yardley||HRC (on order)|
(c) 2009 Moshe Rubin, All Rights Reserved.
Last updated: 1 April 2011