Joseph Rochefort
Encyclopedia
Joseph John Rochefort was an American Naval officer and cryptanalyst. His contributions and those of his team were pivotal to victory in the Pacific War
.
Rochefort was a major figure in the United States Navy
's cryptographic and intelligence operations from 1925 to 1946, particularly in the Battle of Midway
.
, and in 1919 became engineering officer of the tanker USS Cuyama
.
A fellow officer observed that Rochefort had a penchant for solving crossword puzzles and adept skills at playing the advanced card game auction bridge
and recommended him for a Navy cryptanalysis class in Washington, D.C.
Rochefort's tours ashore included cryptanalytic training under Captain Laurance Safford
as his assistant, and worked with the master codebreaker Agnes Meyer Driscoll
in 1924.
He then served a stint as second chief of the Division of Naval Communications' newly created cryptanalytic organization, OP-20-G
, from 1926 to 1929; training in the Japanese language
from 1929 to 1932; and a two-year intelligence assignment in the Eleventh Naval District, San Diego, from 1936 to 1938. Until 1941, Rochefort spent nine years in cryptologic or intelligence-related assignments and fourteen years at sea with the U.S. Fleet in positions of increasing responsibility.
to become Officer in Charge of Station Hypo
("H" for Hawaii in the Navy's phonetic alphabet
at the time) in Pearl Harbor
as Rochefort was an expert Japanese linguist and trained cryptanalyst.
Rochefort handpicked many of HYPO's staff, and by the time of Pearl Harbor
, had gotten many of the Navy's best cryptanalysts, traffic analyst
s, and linguists, including Joseph Finnegan
. Rochefort's team was assigned to break the Japanese Navy's most secure cypher system, the Flag Officers Code, while Navy cryptographers at Station CAST
(Cavite
in the Philippines) and OP-20-G
in Washington (NEGAT, "N" for Navy Department) concentrated on the main fleet cipher, JN-25
.
Rochefort had a close working relationship with Edwin T. Layton
, whom he first met on the voyage to Tokyo where both men were sent to learn Japanese at the Navy's request. In 1941, Layton was the chief intelligence officer for Admiral Husband E. Kimmel
, Commander in Chief, Pacific Fleet (CINCPAC
). Both he and Rochefort were denied access to decrypts of diplomatic messages sent in Purple, the highest level diplomatic cypher, in the months before the Japanese attack, on the orders Director of the War Plans Division, Richmond K. Turner
. That this would have helped is in question.
(in Hong Kong, later Singapore, later Ceylon), and Dutch cryptographers (in the Dutch East Indies
), combined to break enough JN-25 traffic to provide useful intelligence reports and assessments regarding Japanese force disposition and intentions in early 1942.
Station HYPO maintained the coming Japanese attack would be in the Central Pacific, and convinced Admiral Chester W. Nimitz (who replaced Kimmel). OP-20-G (with support from Station CAST) insisted it would be elsewhere in the Pacific, probably the Aleutian Islands. possibly Port Moresby
in Papua New Guinea
, or even the west coast of the United States. OP-20-G, which had been restructured (Safford having been replaced by Commander John Redman
, a communications officer untrained in cryptanalys) agreed the attack was scheduled for mid-June, not late May or early June, as Rochefort maintained. Admiral Ernest King
, Nimitz's superior in Washington, was persuaded by OP-20-G. Rochefort believed an unknown codegroup, AF, referred to Midway.
One of the Station HYPO staff, Jasper Holmes, had the idea of faking a water supply failure on Midway Island. He suggested using an unencrypted emergency warning, in the hope of provoking a Japanese response, thus establishing whether Midway was a target. Rochefort took the idea to Layton, who put it to Nimitz. Nimitz approved.
The Japanese took the bait. They broadcast instructions to load additional water desalination
equipment, confirming Rochefort’s analysis. Layton notes the instructions also “produced an unexpected bonus”. They revealed the assault was to come before mid-June.
Washington still was not convinced, however, as to the date of the attack. The date-time data in Japanese naval messages was “superenciphered,” or encrypted even before it was encoded in JN-25. HYPO made their all-out effort to crack this by searching the stacks of printouts and punched cards for five-digit number sequences. After finding low-grade codes, the team set about to unravel the cipher itself. Layton credits Lieutenant Joseph Finnegan
for discovering "the method that the Japanese had used to lock up their date-time groups." An intercept of 26 May with orders for two destroyer groups escorting invasion transports was analyzed with this table and “really clinched the pivotal date of the operation” as either 4 or 5 June.
During May 1942, Rochefort and his group decrypted, translated, reviewed, analyzed, and reported as many as 140 messages per day. During the week before Nimitz issued his final orders, "decrypts were being processed at the rate of five hundred to a thousand a day."
When Nimitz recommended Rochefort for a Distinguished Service Medal
, Rochefort said that it would only "make trouble". Other sources suggest Rochefort received no official recognition during his lifetime because he was made a scapegoat for the embarrassment of OP-20-G. Redman (whose brother was the influential Rear Admiral Joseph Redman
) complained about the operation of the Hawaii station; as a result, Rochefort was reassigned from cryptanalysis to command a floating dry dock at San Francisco. Rochefort never served at sea again. The fact that Rochefort received no recognition at the time is considered by some to have been an outrage.
Rochefort headed the Pacific Strategic Intelligence Group in Washington after the war.
. In 1986, he was posthumously awarded the Presidential Medal of Freedom
. In 2000, he was inducted into the National Security Agency
, Central Security Service
Hall of Fame.
, Rochefort was portrayed by Hal Holbrook
.
Pacific War
The Pacific War, also sometimes called the Asia-Pacific War refers broadly to the parts of World War II that took place in the Pacific Ocean, its islands, and in East Asia, then called the Far East...
.
Rochefort was a major figure in the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
's cryptographic and intelligence operations from 1925 to 1946, particularly in the Battle of Midway
Battle of Midway
The Battle of Midway is widely regarded as the most important naval battle of the Pacific Campaign of World War II. Between 4 and 7 June 1942, approximately one month after the Battle of the Coral Sea and six months after Japan's attack on Pearl Harbor, the United States Navy decisively defeated...
.
Early career
In 1917, Rochefort had joined the Navy while still in high school in Los Angeles. He enlisted in the Navy in 1918. He was commissioned as an ensign after graduation from the Stevens Institute of TechnologyStevens Institute of Technology
Stevens Institute of Technology is a technological university located on a campus in Hoboken, New Jersey, USA – founded in 1870 with an 1868 bequest from Edwin A. Stevens. It is known for its engineering, science, and technological management curricula.The institute has produced leading...
, and in 1919 became engineering officer of the tanker USS Cuyama
USS Cuyama (AO-3)
USS Cuyama was a tanker of the United States Navy launched 17 June 1916 by Mare Island Navy Yard; sponsored by Miss M. Offley; and commissioned 2 April 1917, Lieutenant I. B. Smith, USNRF, in command....
.
A fellow officer observed that Rochefort had a penchant for solving crossword puzzles and adept skills at playing the advanced card game auction bridge
Auction bridge
The card game auction bridge, the third step in the evolution of the general game of bridge, was developed from straight bridge in 1904. The precursor to contract bridge, its predecessors were whist and bridge whist....
and recommended him for a Navy cryptanalysis class in Washington, D.C.
Washington, D.C.
Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....
Rochefort's tours ashore included cryptanalytic training under Captain Laurance Safford
Laurance Safford
Captain Laurance F. Safford was a U.S. Navy cryptologist. He established the Naval cryptologic organization after World War I, and headed the effort more or less constantly until shortly after the Japanese attack on Pearl Harbor. His identification with the Naval effort was so close that he was...
as his assistant, and worked with the master codebreaker Agnes Meyer Driscoll
Agnes Meyer Driscoll
Agnes Meyer Driscoll was, known as Miss Aggie or Madame X, an Americancryptanalyst during both World War I and World War II.-Early years:...
in 1924.
He then served a stint as second chief of the Division of Naval Communications' newly created cryptanalytic organization, 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...
, from 1926 to 1929; training in the Japanese language
Japanese language
is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
from 1929 to 1932; and a two-year intelligence assignment in the Eleventh Naval District, San Diego, from 1936 to 1938. Until 1941, Rochefort spent nine years in cryptologic or intelligence-related assignments and fourteen years at sea with the U.S. Fleet in positions of increasing responsibility.
Pearl Harbor
In early 1941, Laurance Safford, again chief of OP-20-G in Washington, sent Rochefort to HawaiiHawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
to become Officer in Charge of Station Hypo
Station HYPO
Station HYPO, also known as Fleet Radio Unit Pacific was the United States Navy signals monitoring and cryptographic intelligence unit in Hawaii during World War II. It was one of two major Allied signals intelligence units, called Fleet Radio Units in the Pacific theaters, along with FRUMEL in...
("H" for Hawaii in the Navy's phonetic alphabet
Spelling alphabet
A spelling alphabet, radio alphabet, or telephone alphabet is a set of words which are used to stand for the letters of an alphabet. Each word in the spelling alphabet typically replaces the name of the letter with which it starts...
at the time) in Pearl Harbor
Pearl Harbor
Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...
as Rochefort was an expert Japanese linguist and trained cryptanalyst.
Rochefort handpicked many of HYPO's staff, and by the time of 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...
, had gotten many of the Navy's best cryptanalysts, traffic analyst
Traffic analysis
Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted and cannot be decrypted. In general, the greater the number of messages observed, or even intercepted and...
s, and linguists, including Joseph Finnegan
Joseph Finnegan (cryptographer)
Joseph Finnegan was a US linguist and cryptanalyst with Station Hypo during the Second World War.In 2002, Tex Biard described Finnegan as "intuitive" and "brilliant", and second only to Station Hypo chief Joseph J...
. Rochefort's team was assigned to break the Japanese Navy's most secure cypher system, the Flag Officers Code, while Navy cryptographers at Station CAST
Station CAST
Station CAST was the United States Navy signals monitoring and cryptographic intelligence fleet radio unit at Cavite Navy Yard in the Philippines, until Cavite was captured by the Japanese forces in 1942, during World War II. It was an important part of the Allied intelligence effort, addressing...
(Cavite
Cavite
Cavite is a province of the Philippines located on the southern shores of Manila Bay in the CALABARZON region in Luzon, just 30 kilometers south of Manila. Cavite is surrounded by Laguna to the east, Metro Manila to the northeast, and Batangas to the south...
in the Philippines) and 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...
in Washington (NEGAT, "N" for Navy Department) concentrated on the main fleet cipher, JN-25
JN-25
The vulnerability of Japanese naval codes and ciphers was crucial to the conduct of World War II, and had an important influence on foreign relations between Japan and the west in the years leading up to the war as well...
.
Rochefort had a close working relationship with Edwin T. Layton
Edwin T. Layton
Edwin Thomas Layton was a Rear Admiral in the United States Navy.-Career:...
, whom he first met on the voyage to Tokyo where both men were sent to learn Japanese at the Navy's request. In 1941, Layton was the chief intelligence officer for Admiral Husband E. Kimmel
Husband E. Kimmel
Husband Edward Kimmel was a four-star admiral in the United States Navy. He served as Commander-in-chief, U.S. Pacific Fleet at the time of the Japanese attack on Pearl Harbor. Because of the attack, he was removed from office and was reduced to his permanent two-star rank of rear admiral...
, Commander in Chief, Pacific Fleet (CINCPAC
Commander, U.S. Pacific Fleet
Commander, U.S. Pacific Fleet , is the title of the United States Navy officer who commands the United States Pacific Fleet. Originally established in 1907 as a two-star rear admiral's billet, the position has been held by a four-star admiral since March 19, 1915.Between 1907 and December 6, 1922,...
). Both he and Rochefort were denied access to decrypts of diplomatic messages sent in Purple, the highest level diplomatic cypher, in the months before the Japanese attack, on the orders Director of the War Plans Division, Richmond K. Turner
Richmond K. Turner
-Footnotes:...
. That this would have helped is in question.
Battle of Midway
After the Japanese attack, Navy cryptographers, with assistance from both British cryptographers at the Far East Combined BureauFar East Combined Bureau
The Far East Combined Bureau, an outstation of the British Government Code and Cypher School, was set up in Hong Kong in March 1935, to monitor Japanese, and also Chinese and Russian intelligence and radio traffic...
(in Hong Kong, later Singapore, later Ceylon), and Dutch cryptographers (in the Dutch East Indies
Dutch East Indies
The Dutch East Indies was a Dutch colony that became modern Indonesia following World War II. It was formed from the nationalised colonies of the Dutch East India Company, which came under the administration of the Netherlands government in 1800....
), combined to break enough JN-25 traffic to provide useful intelligence reports and assessments regarding Japanese force disposition and intentions in early 1942.
Station HYPO maintained the coming Japanese attack would be in the Central Pacific, and convinced Admiral Chester W. Nimitz (who replaced Kimmel). OP-20-G (with support from Station CAST) insisted it would be elsewhere in the Pacific, probably the Aleutian Islands. possibly Port Moresby
Port Moresby
Port Moresby , or Pot Mosbi in Tok Pisin, is the capital and largest city of Papua New Guinea . It is located on the shores of the Gulf of Papua, on the southeastern coast of the island of New Guinea, which made it a prime objective for conquest by the Imperial Japanese forces during 1942–43...
in Papua New Guinea
Papua New Guinea
Papua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, or even the west coast of the United States. OP-20-G, which had been restructured (Safford having been replaced by Commander John Redman
John R. Redman
John "Jack" Roland Redman was an admiral in the United States Navy. A naval communications officer, he played key roles in signals intelligence during World War II in Washington, D.C., and on the staff of Admiral Chester W...
, a communications officer untrained in cryptanalys) agreed the attack was scheduled for mid-June, not late May or early June, as Rochefort maintained. Admiral Ernest King
Ernest King
Fleet Admiral Ernest Joseph King was Commander in Chief, United States Fleet and Chief of Naval Operations during World War II. As COMINCH, he directed the United States Navy's operations, planning, and administration and was a member of the Joint Chiefs of Staff. He was the U.S...
, Nimitz's superior in Washington, was persuaded by OP-20-G. Rochefort believed an unknown codegroup, AF, referred to Midway.
One of the Station HYPO staff, Jasper Holmes, had the idea of faking a water supply failure on Midway Island. He suggested using an unencrypted emergency warning, in the hope of provoking a Japanese response, thus establishing whether Midway was a target. Rochefort took the idea to Layton, who put it to Nimitz. Nimitz approved.
The Japanese took the bait. They broadcast instructions to load additional water desalination
Desalination
Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from saline water...
equipment, confirming Rochefort’s analysis. Layton notes the instructions also “produced an unexpected bonus”. They revealed the assault was to come before mid-June.
Washington still was not convinced, however, as to the date of the attack. The date-time data in Japanese naval messages was “superenciphered,” or encrypted even before it was encoded in JN-25. HYPO made their all-out effort to crack this by searching the stacks of printouts and punched cards for five-digit number sequences. After finding low-grade codes, the team set about to unravel the cipher itself. Layton credits Lieutenant Joseph Finnegan
Joseph Finnegan (cryptographer)
Joseph Finnegan was a US linguist and cryptanalyst with Station Hypo during the Second World War.In 2002, Tex Biard described Finnegan as "intuitive" and "brilliant", and second only to Station Hypo chief Joseph J...
for discovering "the method that the Japanese had used to lock up their date-time groups." An intercept of 26 May with orders for two destroyer groups escorting invasion transports was analyzed with this table and “really clinched the pivotal date of the operation” as either 4 or 5 June.
During May 1942, Rochefort and his group decrypted, translated, reviewed, analyzed, and reported as many as 140 messages per day. During the week before Nimitz issued his final orders, "decrypts were being processed at the rate of five hundred to a thousand a day."
When Nimitz recommended Rochefort for a Distinguished Service Medal
Distinguished Service Medal (United States)
The Distinguished Service Medal is the highest non-valorous military and civilian decoration of the United States military which is issued for exceptionally meritorious service to the government of the United States in either a senior government service position or as a senior officer of the United...
, Rochefort said that it would only "make trouble". Other sources suggest Rochefort received no official recognition during his lifetime because he was made a scapegoat for the embarrassment of OP-20-G. Redman (whose brother was the influential Rear Admiral Joseph Redman
Joseph Redman
Joseph Reasor Redman was an admiral in the United States Navy. A naval communications officer, he played key roles in signals intelligence during World War II in Washington, D.C.- Biography :...
) complained about the operation of the Hawaii station; as a result, Rochefort was reassigned from cryptanalysis to command a floating dry dock at San Francisco. Rochefort never served at sea again. The fact that Rochefort received no recognition at the time is considered by some to have been an outrage.
Rochefort headed the Pacific Strategic Intelligence Group in Washington after the war.
Awards
In 1985, Rochefort was posthumously awarded the Navy Distinguished Service MedalNavy Distinguished Service Medal
The Navy Distinguished Service Medal is a military award of the United States Navy and United States Marine Corps which was first created in 1919. The decoration is the Navy and Marine Corps equivalent to the Army Distinguished Service Medal, the Air Force Distinguished Service Medal, and the Coast...
. In 1986, he was posthumously awarded the Presidential Medal of Freedom
Presidential Medal of Freedom
The Presidential Medal of Freedom is an award bestowed by the President of the United States and is—along with thecomparable Congressional Gold Medal bestowed by an act of U.S. Congress—the highest civilian award in the United States...
. In 2000, he was inducted into the 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...
, Central Security Service
Central Security Service
The Central Security Service is an agency of the United States Department of Defense, established in 1972 by a Presidential Directive to promote full partnership between the National Security Agency and the Service Cryptologic Elements of the United States Armed Forces.-Organization:The blue...
Hall of Fame.
Portrayals
In the movie MidwayMidway (film)
Midway is a 1976 war film directed by Jack Smight and produced byWalter Mirisch from a screenplay by Donald S. Sanford. The music score was by John Williams and the cinematography by Harry Stradling, Jr...
, Rochefort was portrayed by Hal Holbrook
Hal Holbrook
Harold Rowe "Hal" Holbrook, Jr. is an American actor. His television roles include Abraham Lincoln in the 1976 TV series Lincoln, Hays Stowe on The Bold Ones: The Senator and Capt. Lloyd Bucher on Pueblo. He is also known for his role in the 2007 film Into the Wild, for which he was nominated for...
.
External links
- NSA online biography Please Note: incorrectly gives Rochefort's year of birth as 1898