William F. Friedman
Encyclopedia
William Frederick Friedman (September 24, 1891 – November 12, 1969) was a US Army
cryptographer
who ran the research division of the Army's Signals Intelligence Service
(SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett
broke Japan
's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II
.
, Bessarabia
, the son of Frederick Friedman, a Jew from Bucharest
who worked as a translator and linguist for the Russian Postal Service, and the daughter of a well-to-do wine merchant. Friedman's family fled Russia in 1892 to escape the virulent anti-Semitism
there, ending up in Pittsburgh, Pennsylvania
. Three years later, his first name was changed to William.
As a child, Friedman was introduced to cryptography in the short story "The Gold-Bug
" by Edgar Allan Poe
. He studied at the Michigan Agricultural College (known today as Michigan State University
) in East Lansing
and received a scholarship to work on genetics
at Cornell University
. Meanwhile George Fabyan
, who ran a private research laboratory to study any personally interesting project, decided to set up his own genetics project and was referred to Friedman. Friedman joined Fabyan's Riverbank Laboratories
outside Chicago in September 1915. As head of the Department of Genetics, one of the projects he ran studied the effects of moonlight on crop growth, and so he experimented with the planting of wheat
during various phases of the moon
.
had allegedly hidden in various texts during the reigns of Elizabeth I
and 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 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 Smith, Mrs. 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 23 papers on cryptography, collectively known as the "Riverbank publications", including the first description of the index of coincidence
, an important mathematical tool in cryptanalysis.
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 German
-funded Hindu
radicals in the US who planned to ship arms to India
to gain independence from Britain. Analysing 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.
. He returned to the US in 1920 and published an eighth monograph, "The Index of Coincidence
and its Applications in Cryptography", considered by some to be the most important publication in modern cryptography to that time. His texts for Army cryptographic training were well thought of and remained classified for several decades.
In 1921 he became chief cryptanalyst for the War Department and later led the Signals Intelligence Service(SIS) -- a position he kept for a quarter century. In 1929, after The American Black Chamber
in New York City was disbanded, its files were entrusted to SIS, and the cryptographic and intelligence services was reorganized to suit its new position at the War Department.
Friedman coined several terms, including "cryptanalysis
", and wrote many monographs on cryptography. One of these (written mostly in his spare time) was the first draft of his Elements of cryptanalysis, which later was expanded to four volumes and became the U.S. Army's cryptographic main textbook and reference. Realizing that mathematical and language skills were essential to SIS' work, Friedman managed to get authority to hire three men with both mathematical training and language knowledge. They were Solomon Kullback
, Frank Rowlett
and Abraham Sinkov
, each of whom went on to distinguished service for decades. In addition he also was finally able to hire a man fluent in Japanese, John Hurt.
During this period Elizebeth Friedman
continued her own work in cryptology, and became famous in a number of trials involving rum-runners and the Coast Guard
and FBI during Prohibition
.
During the 1920s, several new cipher machines were developed generally based on using typewriter
mechanics and basic electrical circuitry. An early example was the Hebern Rotor Machine
, designed in the US in 1915 by Edward Hebern
. This system offered such security and simplicity of use that Hebern heavily promoted it to investors.
Friedman realized that the new rotor machines would be important, and devoted some time to analysing Hebern's design. Over a period of years, he developed principles of analysis and discovered several problems common to most rotor-machine designs. Examples of some dangerous features included having rotors step one position with each keypress, and putting the fastest rotor (the one that turns with every keypress) at either end of the rotor series. In this case, by collecting enough ciphertext
and applying a standard statistical method known as the kappa test, he showed that he could, albeit with great difficulty, crack any cipher generated by such a machine.
Friedman used his understanding of rotor machines to develop several that were immune to his own attacks. The best of the lot, the SIGABA
— which was destined to become the US's highest-security cipher machine in World War II
— was co-invented by Frank Rowlett
. At least one patent related to it was finally granted after Friedman had died.
In 1939, the Japanese introduced a new cipher machine for their most sensitive diplomatic traffic, replacing an earlier system that SIS referred to as "RED." The new cipher, which SIS called "PURPLE", was different and much more difficult. The Navy's cryptological unit (OP-20-G) and the SIS thought it might be related to earlier Japanese cipher machines, and agreed that SIS would handle the attack on the system. After several months trying to discover underlying patterns in PURPLE ciphertexts, an SIS team led by Friedman and Rowlett
, in an extraordinary achievement, figured it out. PURPLE, unlike the German Enigma or the Hebern
design, did not use rotor
s but stepper switches
like those in automated telephone exchange
s. Leo Rosen
of SIS built a machine — as was later discovered, using the identical model of switch that the Japanese designer had chosen.
Thus, by the end of 1940, SIS had constructed an exact analog of the PURPLE machine without ever having seen one. With the duplicate machines and an understanding of PURPLE, SIS could decrypt increasing amounts of Japanese traffic. One such intercept was the message to the Japanese Embassy in Washington, D.C., ordering an end (on December 7, 1941) to negotiations with the US. The message gave a clear indication of impending war
, and was to have been delivered to the US State Department only hours prior to the attack on Pearl Harbor
. The controversy over whether the US had foreknowledge of the Pearl Harbor attack
has roiled well into the 21st century.
In 1941, Friedman was hospitalized with a "nervous breakdown
", widely attributed to the mental strain of his work on PURPLE. While he remained in hospital, a four-man team — Abraham Sinkov
and Leo Rosen
from SIS, and Lt. Prescott Currier and Lt. Robert Weeks from the U.S. Navy's OP-20-G
— visited the British establishment at the "Government Code and Cypher School" at Bletchley Park
. They gave the British a PURPLE machine, in exchange for details on the design of the Enigma machine
and on how the British decrypted the Enigma cipher
. However Friedman visited Bletchley Park in April 1943 and played a key role in drawing up the 1943 BRUSA Agreement
.
Following World War II, Friedman remained in government signals intelligence. In 1949 he became head of the cryptographic division of the newly-formed Armed Forces Security Agency (AFSA) and in 1952 became chief cryptologist for the National Security Agency
(NSA) when it was formed to take over from AFSA. Friedman produced a classic series of textbooks, "Military Cryptanalysis", which was used to train NSA students. (These were revised and extended, under the title "Military Cryptanalytics
", by Friedman's assistant and successor Lambros D. Callimahos
, and used to train many additional cryptanalysts.) During his early years at NSA, he encouraged it to develop what was probably the first super-computers, although he was never convinced a machine could have the "insight" of a human mind.
Friedman spent much of his free time trying to decipher the famous Voynich Manuscript
, written sometime between 1403-1437. However, after four decades of study he finally had to admit defeat, contributing no more than an educated guess as to its origins and meaning.
Friedman retired in 1956 and, with his wife, turned his attention to the problem that had originally brought them together: examining Bacon's supposed codes. Together they wrote a book entitled The Cryptologist Looks at Shakespeare which won a prize from the Folger Library and was published under the title The Shakespearean Ciphers Examined. The book demonstrated flaws in Gallup's work and in that of others who sought hidden ciphers in Shakespeare's work.
At NSA's request Friedman prepared Six Lectures Concerning Cryptography and Cryptanalysis, which he delivered at NSA. But later the Agency, concerned about security, confiscated the reference materials from Friedman's home.
Friedman has been inducted into the Military Intelligence Hall of Fame
and there is a building named after William and Elizebeth at the NSA complex at Fort George G. Meade in Maryland. He was also presented the Medal for Merit by President Harry Truman, and the National Security Medal
by Dwight Eisenhower.
Friedman has the distinction of having one of the longest known suppressed patent applications, for , a patent for a "cryptographic system". It was filed on July 25, 1933, issued on August 1, 2000.
United States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
cryptographer
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
who ran the research division of the Army's Signals Intelligence Service
Signals Intelligence Service
The Signals Intelligence Service was the United States Army codebreaking division, headquartered at Arlington Hall. It was a part of the Signal Corps so secret that outside the office of the Chief Signal officer, it did not officially exist. William Friedman began the division with three "junior...
(SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett
Frank Rowlett
Frank Byron Rowlett was an American cryptologist.Rowlett was born in Rose Hill, Virginia and attended Emory & Henry College in Emory, Virginia, where he was a member of the Beta Lambda Zeta fraternity. In 1929 he received a bachelor's degree in mathematics and chemistry...
broke Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
Early life
Friedman was born Wolf Friedman , in KishinevChisinau
Chișinău is the capital and largest municipality of Moldova. It is also its main industrial and commercial centre and is located in the middle of the country, on the river Bîc...
, Bessarabia
Bessarabia
Bessarabia is a historical term for the geographic region in Eastern Europe bounded by the Dniester River on the east and the Prut River on the west....
, the son of Frederick Friedman, a Jew from Bucharest
Bucharest
Bucharest is the capital municipality, cultural, industrial, and financial centre of Romania. It is the largest city in Romania, located in the southeast of the country, at , and lies on the banks of the Dâmbovița River....
who worked as a translator and linguist for the Russian Postal Service, and the daughter of a well-to-do wine merchant. Friedman's family fled Russia in 1892 to escape the virulent anti-Semitism
Anti-Semitism
Antisemitism is suspicion of, hatred toward, or discrimination against Jews for reasons connected to their Jewish heritage. According to a 2005 U.S...
there, ending up in Pittsburgh, Pennsylvania
Pittsburgh, Pennsylvania
Pittsburgh is the second-largest city in the US Commonwealth of Pennsylvania and the county seat of Allegheny County. Regionally, it anchors the largest urban area of Appalachia and the Ohio River Valley, and nationally, it is the 22nd-largest urban area in the United States...
. Three years later, his first name was changed to William.
As a child, Friedman was introduced to cryptography in the short story "The Gold-Bug
The Gold-Bug
"The Gold-Bug" is a short story by Edgar Allan Poe. Set on Sullivan's Island, South Carolina, the plot follows William Legrand, who was recently bitten by a gold-colored bug. His servant Jupiter fears him to be going insane and goes to Legrand's friend, an unnamed narrator who agrees to visit his...
" by Edgar Allan Poe
Edgar Allan Poe
Edgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...
. He studied at the Michigan Agricultural College (known today as Michigan State University
Michigan State University
Michigan State University is a public research university in East Lansing, Michigan, USA. Founded in 1855, it was the pioneer land-grant institution and served as a model for future land-grant colleges in the United States under the 1862 Morrill Act.MSU pioneered the studies of packaging,...
) in East Lansing
East Lansing, Michigan
East Lansing is a city in the U.S. state of Michigan. The city is located directly east of Lansing, Michigan, the state's capital. Most of the city is within Ingham County, though a small portion lies in Clinton County. The population was 48,579 at the time of the 2010 census, an increase from...
and received a scholarship to work on genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
at Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
. Meanwhile George Fabyan
George Fabyan
George Fabyan was a millionaire businessman who founded a private research laboratory. Fabyan's laboratory pioneered modern cryptography, though its initial findings, supporting Fabyan's belief that Francis Bacon wrote Shakespeare's plays, were later disproven by the cryptographers who trained...
, who ran a private research laboratory to study any personally interesting project, decided to set up his own genetics project and was referred to Friedman. Friedman joined Fabyan's Riverbank Laboratories
Riverbank Laboratories
Riverbank Laboratories, or Riverbank Labs, is a company on Route 31 in Geneva, Illinois that started in 1918. This company has played an instrumental piece in the United States history of World War I for decrypting the German and Mexican code. The current address for the company is 1512 Batavia Ave...
outside Chicago in September 1915. As head of the Department of Genetics, one of the projects he ran studied the effects of moonlight on crop growth, and so he experimented with the planting of wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
during various phases of the moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
.
Initial work in cryptology
Another of Fabyan's pet projects was research into secret messages which Sir Francis BaconFrancis Bacon
Francis Bacon, 1st Viscount St Albans, KC was an English philosopher, statesman, scientist, lawyer, jurist, author and pioneer of the scientific method. He served both as Attorney General and Lord Chancellor of England...
had allegedly hidden in various texts during the reigns of Elizabeth I
Elizabeth I of England
Elizabeth I was queen regnant of England and Ireland from 17 November 1558 until her death. Sometimes called The Virgin Queen, Gloriana, or Good Queen Bess, Elizabeth was the fifth and last monarch of the Tudor dynasty...
and James I
James I of England
James VI and I was King of Scots as James VI from 24 July 1567 and King of England and Ireland as James I from the union of the English and Scottish crowns on 24 March 1603...
. The research was carried out by Elizabeth Wells Gallup
Elizabeth Wells Gallup
Elizabeth Wells Gallup was an American educator and exponent of the Baconian theory of Shakespearian authorship....
. She believed that she had discovered many such messages in the works of William Shakespeare
William Shakespeare
William Shakespeare was an English poet and playwright, widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's national poet and the "Bard of Avon"...
, and convinced herself that Bacon had written many, if not all, of Shakespeare
William Shakespeare
William Shakespeare was an English poet and playwright, widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's national poet and the "Bard of Avon"...
'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 Smith, Mrs. 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 23 papers on cryptography, collectively known as the "Riverbank publications", including the first description of the index of coincidence
Index of coincidence
In cryptography, coincidence counting is the technique of putting two texts side-by-side and counting the number of times that identical letters appear in the same position in both texts...
, an important mathematical tool in cryptanalysis.
With the entry of the United States into World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
, 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 German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
-funded Hindu
Hindu
Hindu refers to an identity associated with the philosophical, religious and cultural systems that are indigenous to the Indian subcontinent. As used in the Constitution of India, the word "Hindu" is also attributed to all persons professing any Indian religion...
radicals in the US who planned to ship arms to India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
to gain independence from Britain. Analysing 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.
Signals Intelligence Service
The United States government decided to set up its own cryptological service, and sent Army officers to Riverbank to train under Friedman. To support the program, Friedman wrote a series of technical monographs, completing seven by early 1918. He then enlisted in the Army and went to France to serve as the personal cryptographer for General John J. PershingJohn J. Pershing
John Joseph "Black Jack" Pershing, GCB , was a general officer in the United States Army who led the American Expeditionary Forces in World War I...
. He returned to the US in 1920 and published an eighth monograph, "The Index of Coincidence
Index of coincidence
In cryptography, coincidence counting is the technique of putting two texts side-by-side and counting the number of times that identical letters appear in the same position in both texts...
and its Applications in Cryptography", considered by some to be the most important publication in modern cryptography to that time. His texts for Army cryptographic training were well thought of and remained classified for several decades.
In 1921 he became chief cryptanalyst for the War Department and later led the Signals Intelligence Service(SIS) -- a position he kept for a quarter century. In 1929, after The American Black Chamber
Black Chamber
The Cipher Bureau otherwise known as The Black Chamber was the United States' first peacetime cryptanalytic organization, and a forerunner of the National Security Agency...
in New York City was disbanded, its files were entrusted to SIS, and the cryptographic and intelligence services was reorganized to suit its new position at the War Department.
Friedman coined several terms, including "cryptanalysis
Cryptanalysis
Cryptanalysis is the study of methods for obtaining the meaning of encrypted information, without access to the secret information that is normally required to do so. Typically, this involves knowing how the system works and finding a secret key...
", and wrote many monographs on cryptography. One of these (written mostly in his spare time) was the first draft of his Elements of cryptanalysis, which later was expanded to four volumes and became the U.S. Army's cryptographic main textbook and reference. Realizing that mathematical and language skills were essential to SIS' work, Friedman managed to get authority to hire three men with both mathematical training and language knowledge. They were Solomon Kullback
Solomon Kullback
Solomon Kullback was an American cryptanalyst and mathematician, who was one of the first three employees hired by William F. Friedman at the US Army's Signal Intelligence Service in the 1930s, along with Frank Rowlett and Abraham Sinkov. He went on to a long and distinguished career at SIS and...
, Frank Rowlett
Frank Rowlett
Frank Byron Rowlett was an American cryptologist.Rowlett was born in Rose Hill, Virginia and attended Emory & Henry College in Emory, Virginia, where he was a member of the Beta Lambda Zeta fraternity. In 1929 he received a bachelor's degree in mathematics and chemistry...
and Abraham Sinkov
Abraham Sinkov
Dr. Abraham Sinkov was a US cryptanalyst.-Biography:Sinkov, the son of immigrants from Russia, was born in Philadelphia, but grew up in Brooklyn. After graduating from Boys High School—what today would be called a "magnet school" -- he took his B.S. in mathematics from City College of New York...
, each of whom went on to distinguished service for decades. In addition he also was finally able to hire a man fluent in Japanese, John Hurt.
During this period Elizebeth Friedman
Elizebeth Friedman
Elizebeth Smith Friedman was a cryptanalyst and author, and a pioneer in U.S. cryptography. The special spelling of her name is attributed to her mother, who disliked the prospect of Elizebeth ever being called "Eliza." She has been dubbed "America's first female cryptanalyst".Although she is...
continued her own work in cryptology, and became famous in a number of trials involving rum-runners and the Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
and FBI during Prohibition
Prohibition
Prohibition of alcohol, often referred to simply as prohibition, is the practice of prohibiting the manufacture, transportation, import, export, sale, and consumption of alcohol and alcoholic beverages. The term can also apply to the periods in the histories of the countries during which the...
.
Solution of cipher machines
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...
mechanics and basic electrical circuitry. An early example was the Hebern Rotor Machine
Hebern rotor machine
The Hebern Rotor Machine was an electro-mechanical encryption machine built by combining the mechanical parts of a standard typewriter with the electrical parts of an electric typewriter, connecting the two through a scrambler...
, designed in the US in 1915 by Edward Hebern
Edward Hebern
Edward Hugh Hebern was an early inventor of rotor machines, devices for encryption.-Background:Edward Hugh Hebern was born in Streator, Illinois on April 23, 1869. His parents were Charles and Rosanna Hebern. They met in Harris County, Texas while Charles was serving as guard and escort from the...
. This system offered such security and simplicity of use that Hebern heavily promoted it to investors.
Friedman realized that the new rotor machines would be important, and devoted some time to analysing Hebern's design. Over a period of years, he developed principles of analysis and discovered several problems common to most rotor-machine designs. Examples of some dangerous features included having rotors step one position with each keypress, and putting the fastest rotor (the one that turns with every keypress) at either end of the rotor series. In this case, by collecting enough ciphertext
Ciphertext
In cryptography, ciphertext is the result of encryption performed on plaintext using an algorithm, called a cipher. Ciphertext is also known as encrypted or encoded information because it contains a form of the original plaintext that is unreadable by a human or computer without the proper cipher...
and applying a standard statistical method known as the kappa test, he showed that he could, albeit with great difficulty, crack any cipher generated by such a machine.
Friedman used his understanding of rotor machines to develop several that were immune to his own attacks. The best of the lot, the SIGABA
SIGABA
In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s...
— which was destined to become the US's highest-security cipher machine in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
— was co-invented by Frank Rowlett
Frank Rowlett
Frank Byron Rowlett was an American cryptologist.Rowlett was born in Rose Hill, Virginia and attended Emory & Henry College in Emory, Virginia, where he was a member of the Beta Lambda Zeta fraternity. In 1929 he received a bachelor's degree in mathematics and chemistry...
. At least one patent related to it was finally granted after Friedman had died.
In 1939, the Japanese introduced a new cipher machine for their most sensitive diplomatic traffic, replacing an earlier system that SIS referred to as "RED." The new cipher, which SIS called "PURPLE", was different and much more difficult. The Navy's cryptological unit (OP-20-G) and the SIS thought it might be related to earlier Japanese cipher machines, and agreed that SIS would handle the attack on the system. After several months trying to discover underlying patterns in PURPLE ciphertexts, an SIS team led by Friedman and Rowlett
Frank Rowlett
Frank Byron Rowlett was an American cryptologist.Rowlett was born in Rose Hill, Virginia and attended Emory & Henry College in Emory, Virginia, where he was a member of the Beta Lambda Zeta fraternity. In 1929 he received a bachelor's degree in mathematics and chemistry...
, in an extraordinary achievement, figured it out. PURPLE, unlike the German Enigma or the Hebern
Hebern rotor machine
The Hebern Rotor Machine was an electro-mechanical encryption machine built by combining the mechanical parts of a standard typewriter with the electrical parts of an electric typewriter, connecting the two through a scrambler...
design, did not use rotor
Rotor machine
In cryptography, a rotor machine is an electro-mechanical device used for encrypting and decrypting secret messages. Rotor machines were the cryptographic state-of-the-art for a prominent period of history; they were in widespread use in the 1920s–1970s...
s but stepper switches
Switch
In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....
like those in automated telephone exchange
Telephone exchange
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...
s. Leo Rosen
Leo Rosen
Leo Rosen was a U.S. cryptanalyst who worked with Frank Rowlett at Signals Intelligence Service before the start of World War II on Japanese ciphers. Rowlett found a method to read the messages enciphered on the Japanese PURPLE machine...
of SIS built a machine — as was later discovered, using the identical model of switch that the Japanese designer had chosen.
Thus, by the end of 1940, SIS had constructed an exact analog of the PURPLE machine without ever having seen one. With the duplicate machines and an understanding of PURPLE, SIS could decrypt increasing amounts of Japanese traffic. One such intercept was the message to the Japanese Embassy in Washington, D.C., ordering an end (on December 7, 1941) to negotiations with the US. The message gave a clear indication of impending war
War
War is a state of organized, armed, and often prolonged conflict carried on between states, nations, or other parties typified by extreme aggression, social disruption, and usually high mortality. War should be understood as an actual, intentional and widespread armed conflict between political...
, and was to have been delivered to the US State Department only hours prior to the attack on Pearl Harbor
Attack on Pearl Harbor
The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...
. The controversy over whether the US had foreknowledge of the Pearl Harbor attack
Pearl Harbor advance-knowledge debate
The Pearl Harbor advance-knowledge conspiracy theory is the idea that the American officials had advance knowledge of Japan's December 7, 1941 attack on Pearl Harbor...
has roiled well into the 21st century.
In 1941, Friedman was hospitalized with a "nervous breakdown
Nervous breakdown
Mental breakdown is a non-medical term used to describe an acute, time-limited phase of a specific disorder that presents primarily with features of depression or anxiety.-Definition:...
", widely attributed to the mental strain of his work on PURPLE. While he remained in hospital, a four-man team — Abraham Sinkov
Abraham Sinkov
Dr. Abraham Sinkov was a US cryptanalyst.-Biography:Sinkov, the son of immigrants from Russia, was born in Philadelphia, but grew up in Brooklyn. After graduating from Boys High School—what today would be called a "magnet school" -- he took his B.S. in mathematics from City College of New York...
and Leo Rosen
Leo Rosen
Leo Rosen was a U.S. cryptanalyst who worked with Frank Rowlett at Signals Intelligence Service before the start of World War II on Japanese ciphers. Rowlett found a method to read the messages enciphered on the Japanese PURPLE machine...
from SIS, and Lt. Prescott Currier and Lt. Robert Weeks from the U.S. Navy's OP-20-G
OP-20-G
OP-20-G or "Office of Chief Of Naval Operations , 20th Division of the Office of Naval Communications, G Section / Communications Security", was the US Navy's signals intelligence and cryptanalysis group during World War II. Its mission was to intercept, decrypt, and analyze naval communications...
— visited the British establishment at the "Government Code and Cypher School" at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
. They gave the British a PURPLE machine, in exchange for details on the design of the Enigma machine
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
and on how the British decrypted the Enigma cipher
Cryptanalysis of the Enigma
Cryptanalysis of the Enigma enabled the western Allies in World War II to read substantial amounts of secret Morse-coded radio communications of the Axis powers that had been enciphered using Enigma machines. This yielded military intelligence which, along with that from other decrypted Axis radio...
. However Friedman visited Bletchley Park in April 1943 and played a key role in drawing up the 1943 BRUSA Agreement
1943 BRUSA Agreement
The 1943 BRUSA Agreement was an agreement between the British and US governments to facilitate co-operation between the US War Department and the British Government Code and Cypher School...
.
National Security Agency
National Security Agency
The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...
(NSA) when it was formed to take over from AFSA. Friedman produced a classic series of textbooks, "Military Cryptanalysis", which was used to train NSA students. (These were revised and extended, under the title "Military Cryptanalytics
Military Cryptanalytics
Military Cryptanalytics is a revision by Lambros D. Callimahos of the series of books written by William F. Friedman under the title Military Cryptanalysis. It also contains contributions by other cryptanalysts. It was a training manual for National Security Agency and military cryptanalysts...
", by Friedman's assistant and successor Lambros D. Callimahos
Lambros D. Callimahos
Lambros Demetrios Callimahos was a US Army cryptologist. Born in Alexandria of Greek parents, the family emigrated to the United States when he was four...
, and used to train many additional cryptanalysts.) During his early years at NSA, he encouraged it to develop what was probably the first super-computers, although he was never convinced a machine could have the "insight" of a human mind.
Friedman spent much of his free time trying to decipher the famous Voynich Manuscript
Voynich manuscript
The Voynich manuscript, described as "the world's most mysterious manuscript", is a work which dates to the early 15th century, possibly from northern Italy. It is named after the book dealer Wilfrid Voynich, who purchased it in 1912....
, written sometime between 1403-1437. However, after four decades of study he finally had to admit defeat, contributing no more than an educated guess as to its origins and meaning.
Friedman retired in 1956 and, with his wife, turned his attention to the problem that had originally brought them together: examining Bacon's supposed codes. Together they wrote a book entitled The Cryptologist Looks at Shakespeare which won a prize from the Folger Library and was published under the title The Shakespearean Ciphers Examined. The book demonstrated flaws in Gallup's work and in that of others who sought hidden ciphers in Shakespeare's work.
At NSA's request Friedman prepared Six Lectures Concerning Cryptography and Cryptanalysis, which he delivered at NSA. But later the Agency, concerned about security, confiscated the reference materials from Friedman's home.
Death and legacy
Friedman's health began to fail in the late 1960s, and he died in 1969. Friedman and his wife donated their archives to the George C. Marshall Library, which also had been raided by NSA security.Friedman has been inducted into the Military Intelligence Hall of Fame
Military Intelligence Hall of Fame
The Military Intelligence Hall of Fame is a Hall of Fame established by the Military Intelligence Corps of the United States Army in 1988 to honor soldiers and civilians who have made exceptional contributions to Military Intelligence...
and there is a building named after William and Elizebeth at the NSA complex at Fort George G. Meade in Maryland. He was also presented the Medal for Merit by President Harry Truman, and the National Security Medal
National Security Medal
The National Security Medal was a decoration of the United States of America officially established by President Harry S. Truman in Executive Order 10431 of January 19, 1953...
by Dwight Eisenhower.
Friedman has the distinction of having one of the longest known suppressed patent applications, for , a patent for a "cryptographic system". It was filed on July 25, 1933, issued on August 1, 2000.
Awards and honors
- 1955 – National Security MedalNational Security MedalThe National Security Medal was a decoration of the United States of America officially established by President Harry S. Truman in Executive Order 10431 of January 19, 1953...
. - 1946 – Medal for Merit
- 1944 – Commendation for Exceptional Civilian Service
In popular culture
- Commander Schoen, a character appearing in Neal StephensonNeal StephensonNeal Town Stephenson is an American writer known for his works of speculative fiction.Difficult to categorize, his novels have been variously referred to as science fiction, historical fiction, cyberpunk, and postcyberpunk...
's novel CryptonomiconCryptonomiconCryptonomicon is a 1999 novel by American author Neal Stephenson. The novel follows the exploits of two groups of people in two different time periods, presented in alternating chapters...
, is to a large extent inspired by Friedman. Schoen shares a significant background and personality traits with Friedman, including being one of the top cryptanalysts of the U.S. Army, breaking Japanese codes prior to Japan's involvement in World War II, and the psychological problems that he suffered from as a result.
External links
- NSA Hall of Honor page on Friedman
- Colonel William F. Friedman (the Godfather of Cryptology) by Robert A. Reeves
- Obituary: "William Friedman Dies; Broke Japanese Code; Truman Gave Cryptanalyst Highest Civilian Award; Marshall Said Work Saved Many American Lives," New York Times. November 3, 1969.
- ARTICLE: The story of William Friedman's role in the Chicago trial that "proved" Francis Bacon wrote Shakespeare