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Secret Writing

Windtalkers (2002) Set during the 1944 Allied invasion of Saipan, John Woo's WWII epic stars Nicolas Cage as a battle-hardened Marine sergeant reluctantly charged with protecting (killing) young private Adam Beach, one of a group of Navajo recruits whose native language became an unbreakable code.

In the beginning, people whispered. Others eavesdropped. And from these humble caveman origins have evolved one of the most powerful forms of intelligence and one of the most important forms of security in the world today. The practice of secret writing in military conflicts traveled to North America. During the American Revolution, the British, their Loyalist allies and the Colonials used a variety of secret writing systems, including codes, ciphers and nomenclators.

Cryptology was of service to Americans even before the United States itself was born. During the Revolutionary period, American patriots often used ciphers to protect their communications. Occasionally during the Revolutionary War, encrypted British messages fell into American hands, and military officers, as well as several members of the Continental Congress, were called upon to solve them.

One of the most efficient Colonial cryptology groups operated in Loyalist-dominated New York City From here, spymasters communicated with General Washington using a nomenclator and concealed messages with stains or invisible inks. They also used a dictionary-based code, in which numbers indicated the locations of intended words in an edition of a particular dictionary known to the sender and receiver. Secret writing allowed rebel agents to send valuable information about British troop strength, morale and supplies.

George Washington had a keen appreciation for the need for intelligence, and it is well known today that he was skillful in using spies to gather data on British forces. He worried about the security of his spies and concerned himself with ciphers for espionage use. He also employed cryptanalysis in the famous case of Dr. Benjamin Church, a Boston physician and Washington’s director general of hospitals. Church was caught sending an enciphered message across the lines. Washington enlisted the aid of Elbridge Gerry (later vice president of the United States) and the Reverend Samuel West. Both broke the cipher, which cloaked a report to a British general about American military plans and capabilities. Church was imprisoned.

In 1838, Samuel Morse transmitted the first recorded telegraph message. The development of Morse code showed that numbers and letters can be transformed into dot-dash patterns. Both sides relied upon the telegraph during the American Civil War. Abraham Lincoln in particular used the new technology to stay in touch with his forces almost in real time. But other, more secret, means of communication also played important roles.

In the American Civil War, the Industrial Revolution first became a close partner with warfare. Armies moved rapidly over rail, and communications had to keep up. Both the Union and the Confederacy depended on the newly invented telegraph to control their armies in distant theaters of war. Both sides adopted visual signal systems for field operations based on waving a single flag. Both types of communications were vulnerable to intercept, which put a premium on encryption to protect friendly messages and on cryptanalysis to read the enemy’s signals. Neither side had cipher systems that could withstand a concerted attack, and this new “communications intelligence” became a major source of information in Washington, Richmond, and many far-flung battlefields.

Union forces employed transposition ciphers to conceal telegraph messages from Confed erate wiretappers and cryptanalysts. Anson Stager, Western Union's first superintendent, devised a word transposition cipher used by Union General George B. McClellan. Historians credit Rose O'Neal Greenhow with leaking strategic information about Union troop movements and numbers that helped Confederate General Pierre G.T. Beauregard achieve victory in the 1861 Battle of Bull Run. Greenhow transmitted the information with a number and symbol substitution cipher.

The invention of wireless radio at the turn of the century brought communications and cryptology into a new era. The new source, then termed “radio intelligence was adopted by the U.S. Navy and the Army, and was first used operationally during the Mexican border incursion of 1916, when the Army pursued Pancho Villa into northern Mexico. The U.S. commander, General Pershing, took with him mobile intercept vans — then known as “radio tractors” — to listen to radio messages sent by Mexican government forces. This was the first mobile intercept station in American history; the use of these mobile units was later adopted by American a forces when Pershing led U.S. forces to France in 1917. All the major combatants in World War I engaged in radio intercept — then known as “listening in” — and cryptanalysis of enemy messages.

Pershing’s forces, like virtually all the others, were well outfitted for radio intelligence work. Army-level support came from Section 8 of the new Army intelligence service. In France, battlefield communications intelligence support was conducted by an organization entitled G2A6, with intercept sites at fixed locations and “radio tractors” following the troops at the front lines.

With the increasing unrest in Europe that presaged WWI, Britain's Parliament ordered an increase in the military's efforts to intercept and decrypt messages. In 1914, this resulted in the birth of a cryptanalytic group known as Section 25 of the Intelligence Division, or "Room 40". It became the Allies' leading code and cipher branch.

Shortly after its creation, Room 40 received a gift: A German codebook obtained by the Russian Navy from a German light cruiser. A British trawler recovered another German codebook. Within weeks, the codebreakers began to decode radio intercepts. Room 40's efforts led to the discovery of a plan for German warships to converge at Dogger Bank, located off England's eastern coast. The British navy met the German vessels, severely damaging two warships and destroying a third.

One of the most famous decryption efforts revealed the contents of an encoded telegram sent on 16 January 1917, by German Foreign Secretary Arthur Zimmermann to the German Minister in Mexico. Germany planned to begin unrestricted submarine warfare against neutral shipping, a strategy that might compel the United States to join the Allies. Concerned that the US might not stay neutral, Zimmermann outlined a proposal for an alliance with Mexico: "make war together, make peace together, generous financial support and an understanding on our part that Mexico is to reconquer the lost territory in Texas, New Mexico, and Arizona." Room 40 intercepted the telegram and decrypted the contents. The revelation spurred the US into the war effort.

At the conclusion of World War I, building on the wartime MI-8, the United States for the first time established a peacetime cryptanalytic organization, which was directed by Herbert 0. Yardley. Yardley had been an important figure in the wartime operations against enemy encrypted communications. After the war, the State and War Departments continued the task, this time targeted against foreign diplomatic cable traffic; Yardley was chosen to lead the effort. His most famous success came in 1923 during the Washington Naval Conference, which was seeking ways to prevent a postwar arms race. Under MI-8, Yardley broke Japanese diplomatic messages and sent the information to the State Department, which in turn used it to negotiate favorable provisions in the final agreements. In 1930, however, a new Secretary of State, Henry Stimson, withdrew the State Department’s funding from MI-8, causing its collapse. No longer in government service, Yardley wrote a “tell-all” book, The American Black Chamber, which publicized MI-8’s achievements. Among other effects, it caused a number of countries to search for and adopt new encryption methods.

After the war, ciphers surpassed codes as a military concealment method. Advancements in electromechanical technology allowed the production of rotor machines that quickly reordered letters to create polyalphabetic ciphers. In the late 1920s, the German military modified an encrypting machine built for use in business. It was called the Enigma and could create immense numbers of electrically generated alphabets.

In the early months of WWII, Britain's new prime minister, Winston Churchill, supported a crypt analysis group at Bletchley Park. Aided by Polish and French sources, Alan Turing led the British effort to crack the Enigma. By late April 1940, Bletchley Park had a machine based on the Poles' "Bombe". The electrical circuits of the eight-foot-high machine imitated the Enigma's rotors. The Bombe decrypted Enigma transmissions recorded by England's intercept stations. Information gleaned from decrypted Nazi messages helped the Allies to win the war.

The U.S. ability to exploit Japan’s diplomatic communications in the early 1940s gave it a distinct advantage in the negotiations of that period. However, by 1941 U.S. Army and Navy cryptanalysts had not solved the military code systems used by the Japanese. Thus, despite high-quality secret information about Japan, the U.S. did not learn in advance that a Japanese Navy task force had been sent to bomb American installations on Hawaii. The Japanese attack at Pearl Harbor and other installations on December 7, 1941, propelled the United States into another world war. In the months immediately after the Pearl Harbor disaster, the U.S. Navy made important breakthroughs in a high-level Japanese Navy code known to the Americans as JN-25. The solution to this system enabled the U.S. to read Japanese planning and operational messages throughout the Pacific War. With this inside knowledge, the U.S. was able to position itself to turn back a Japanese naval thrust into the Coral Sea near Australia, and, in May 1942, handed the Japanese Navy a resounding defeat at the island of Midway.

General George S. Patton, the legendary commander of World War II, became an astute consumer of communications intelligence (COMINT); he learned its worth in the drive across Western Europe after D-Day and used it well. For example, in mid-August 1944, while Patton’s Third Army was located near the French city of Le Mans, the general and about 40 of his officers attended daily intelligence briefings. Here they would hear regular briefings by the G-2 (Intelligence) and G-3 (Operations), situation reports, and a news report from radio broadcasts. Following each meeting, all but seven officers were dismissed, and the rest stayed for a briefing on the enemy situation as seen in COMINT. This source proved valuable for the Third Army: ULTRA (the codeword assigned to COMINT derived from decryption of high-level German ciphers) material alone predicted a drive by five German Panzer divisions against the Third Army at Avaranches. In another instance, when Third Army headquarters moved near Chalons, an ULTRA message arrived at 0100 hours showing the German order for an attack at 0300. Patton had described the U.S. troops in the attack areas as spread out as “thin as the skin on an egg.” He found means to alert the defending divisions without jeopardizing the security of ULTRA, and the German attack was repulsed. One member of Patton’s staff wrote about the value of ULTRA to Patton’s army stating that, “An army has never moved as fast and as far as the Third Army in its drive across France, and ULTRA was invaluable every mile of the way.”

The US military did not abandon code concealments during WWII. The Army and the Marine Corp recruited Native Americans who would communicate in their traditional language. These Code Talkers overcame the basic flaw of codes; they did not need codebooks. Historians credit the Code Talkers with never making a mistake in transmission and for using a technique that the enemy never broke.

Cryptology did not win the war. The war was won by the brave soldiers, sailors, airmen, and Marines who risked their lives in combat with the enemy. However, the ability to read the enemy’s most secret messages allowed American and British commanders to make wise decisions about the use of their troops; this shortened the time of war and saved countless thousands of Allied lives. The ironclad protection of U.S. high-level communications prevented the enemy’s intelligence personnel from exploiting these messages; this superior communications security effort also saved an untold number of lives and contributed greatly to the success of Allied operations.

Despite the historic achievements of American cryptology during World War II, the Army and Navy emerged from the war as disunited rivals in the business. In 1947, the Air Force became a third competitor for funding, equipment, and personnel. At the same time, the technology of cryptology had become much more sophisticated through the use of powerful machines and rudimentary computers and, hence, much more expensive. Several forward-looking leaders recognized the necessity to merge the efforts of both services to attack increasingly sophisticated targets. Joseph Wenger, one of Laurance Safford’s earliest recruits to OP-20-G, urged more cooperation with the Army. After several unsuccessful attempts to achieve economy and compatibility of operations through plans for coordination, in 1949 the Secretary of Defense established a central cryptologic institution, the Armed Forces Security Agency (AFSA). Under the Joint Chiefs of Staff, AFSA was intended to be the unifying organization, but it lacked the enforcement powers to make it dominant. What resulted from good intentions was yet a fourth cryptologic contender, which had to compete with the other three service agencies for resources.

President Truman in 1952 impaneled a high-level committee chaired by George Brownell, a New York lawyer, after hearing reports from the director of the Central Intelligence Agency, Walter Bedell Smith, and the Secretary of State, Dean Acheson, that AFSA was not working. The Brownell Committee, concluding that cryptology was a “national asset,” recommended that cryptology be taken from control of the Joint Chiefs of Staff and resubordinated to the Secretary of Defense. The Secretary was made the Executive Agent for SIGINT for the government. Truman established NSA with nothing more than a signature in November 1952.

President Dwight D. Eisenhower, concerned about Soviet strategic capabilities, cast about for information regarding this threat. Until CIA U-2s began flying in 1956, virtually nothing definite was available about the USSR except from SIGINT. In fact, a panel in 1954 judged that 90 percent of America’s warning information would come from SIGJNT. Under the Eisenhower administration, NSA began expanding and enhancing its capabilities. Worried about timely warning, the president supported development of communications for critical information. In the early 1950s, SIGINT sites began sprouting up in Europe to warn the U.S. and NATO of a possible Soviet attack.

A U-2 flight on October 14, 1962, discovered the presence of Soviet offensive nuclear missiles in Cuba. Although photography provided the early information, all intelligence sources, including SIGINT, were tasked to find more information. NSA’s most effective response was to send a SIGINT collection vessel, the Oxford, to Cuban waters to monitor Cuban and Soviet communications. During the tense moments following President Kennedy’s imposition of a naval quarantine around Cuba, SIGINT provided the first indication that Soviet vessels had stopped in the mid-Atlantic, awaiting further instructions. It was the first clue that the Soviets might not challenge the American forces arrayed around the island. SIGINT also provided indications when the Soviets ended the period of crisis. Although photographic intelligence raised the initial warning, SIGINT provided much of the operational intelligence to President Kennedy and other military and civilian decision-makers during the crisis.

As in America’s previous wars, U.S. SIGINT capabilities supported American troops during combat operations in the field during the Vietnam War — but not without tragic losses. Davis Station, first occupied in 1961, was named for SP4 James T. Davis, who arrived with the first Army Security Agency (ASA) contingent to Vietnam. Davis was on a direction finding (DF) mission when his truck was ambushed by Viet Cong south of Saigon. Ten of the eleven on the truck, including Davis, were killed. Davis was the first American serviceman killed in action during the Vietnam conflict.

Vietnam was not the last war in which cryptology supported American forces. After Desert Storm, the desert campaign to liberate Kuwait from Iraqi aggression, there was appreciation for cryptologic support. The dedicated cryptologists were “unsung heroes.” Although the story of American cryptology has had to remain secret for decades, the ability to protect U.S. official communications and the ability to exploit the communications of enemies or potential enemies helped keep the United States out of war, shortened the time of war when combat was inevitable, and saved tens of thousands of American and Allied lives.

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