The Secret Sentry (3 page)

A Brief Shining Moment: The Break Into the Soviet Ciphers

Almost immediately after the signing of the BRUSA Agreement, the U.S. intelligence community’s knowledge about what was transpiring
inside the USSR began to improve, as the joint Anglo-American code-breaking enterprise—Bourbon—made dramatic progress solving
a number of Soviet cipher systems.
²⁴

The British end of Bourbon was run from a motley, drab collection of buildings hidden behind high walls in the nondescript
London suburb of Eastcote, which was the new home of the GCHQ. (Better quarters would later be established in the somewhat
more balmy climate of Cheltenham.)
²⁵

The man who ran the British end of the Bourbon project was the head of the 140-man GCHQ Russian Cryptographic Section, Richard
Pritchard.
²⁶
Pritchard, who had managed the secret British cryptanalytic attack on Russian codes and ciphers during World War II, was
one of those rare people blessed with multiple gifts. He had extraordinary mathematical talent and a genius for music, and
he was a natural cryptanalyst to boot. F. W. Winterbotham, author of
The Ultra Secret
, described Pritchard as “young, tall, clean-shaven, rather round of face, with a quiet voice, could talk on any subject with
witty penetration. He, too, was deeply musical.”
²⁷

Pritchard assembled a small but remarkably talented group of veteran code breakers to work on Bourbon, the two most important
of whom were Conel Hugh O’Donel Alexander, an extraordinarily gifted cryptanalyst and former British chess grand master, and
Major Gerry Morgan, a brilliant machine cryptanalyst and the head of GCHQ’s Crypto Research Section, which contained the best
of the British cryptanalysts who had chosen to remain on in government service after the war.
²⁸

The level of “customer satisfaction” would soon begin to rise rapidly. In the span of only a year, teams of code breakers
on both sides of the Atlantic accomplished an astounding series of cryptanalytic breakthroughs that, for an all-too-brief
moment in time, gave the leaders of the United States and Great Britain unparalleled access to what was going on inside the
Soviet Union, especially within the Russian military.

In February 1946, less than a month before the signing of the BRUSA Agreement, ASA cryptanalysts at Arlington Hall Station
in Virginia managed to reconstruct the inner workings of a Soviet cipher machine that they called Sauterne, which was used
on Red Army radio networks in the Far East. On March 1, 1946, a veteran U.S. Army cryptanalyst at Arlington Hall named Robert
Ferner managed to produce the first decrypted message from a Sauterne intercept. By the end of the month, U.S. Navy cryptanalysts
had discovered a means of determining the daily rotor settings used to encipher all messages on the Sauterne cipher machine,
with the result that on April 4, 1946, a regular supply of Sauterne decrypts began to be produced.
²⁹
The translations of the Sauterne decrypts provided a window into what the Russian army was up to in the Far East.
³⁰

At the same time that Sauterne was solved, GCHQ began producing the first intelligence derived from its solution of another
Russian army cipher machine system, which the British called Coleridge and which was used to encrypt traffic on Russian army
radioteletype networks in the European half of the Soviet Union.
³¹
Alexander led the cryptanalytic attack on Coleridge. He had returned to code-breaking work after a brief, unhappy stint working
as a financier in London because he could notstand a job “that involved a black jacket and striped trousers.”
³²
Assisting Alexander on the other side of the Atlantic was a team of U.S. Navy code breakers led by one of the best machine
cryptanalysts in America, Francis “Frank” Raven. A 1934 graduate of Yale University, Raven had worked as the assistant manager
of the Allegheny Ludlum Steel Company in Pittsburgh before joining the navy COMINT organization in 1942. An incredibly talented
cryptanalyst, during the war he had been instrumental in solving a number of Japanesenavy cipher machine systems.
³³
The Coleridge decrypts were found to contain reams of administrative traffic for the Soviet military, but when analyzed,
they yielded vitally important information about its order of battle, training activities, and logistical matters.
³⁴

At about the same time, the Anglo-American cryptanalysts made their first entry into a third Russian cipher machine system,
designated Longfellow. By July 1946, a copy of the Longfellow cipher machine had been constructed by U.S. Navy cryptanalysts
in Washington, D.C., based on technical specifications provided by the British cryptanalysts who had solved the system, but
the solution of the cipher settings used on the Longfellow machine required several more months of work. Finally, in February
1947 a team of British cryptanalysts led by Gerry Morgan and a team of U.S. Navy analysts in Washington, headed by Commander
Howard Campaigne, together solved the encryption system used by the Soviet army’s Longfellow cipher machine system.
³⁵

But the value of the decrypts of Longfellow traffic that were just beginning to be produced in the spring of 1947 was eclipsed
by the ever-rising volume of translations being produced across the Atlantic at GCHQ through the exploitation of the Coleridge
cipher machine. These decrypts proved to be so valuable that, according to a report by the U.S. Navy liaison officer assigned
to GCHQ, Coleridge was “the most important, high-level system from which current intelligence may be produced and is so in
fact regarded here.”
³⁶

The net result was that by the spring of 1947, translations of decrypted messages from all three systems were being produced
in quantity. At Arlington Hall, the ASA cryptanalysts alone were churning out 341 decrypts a day, seven days a week, 365 days
a year, most of which were derived from Russian radio intercepts.
³⁷
By early 1949, more than 12,500 translations of decrypted Russian army radio messages had been published by ASA and sent
to intelligence consumers in Washington.
³⁸

The Anglo-American cryptanalysts were also experiencing considerable success in solving the cipher systems used by the Soviet
navy. By early 1947, a number of Russian navy ciphers used in the Far East had been successfully solved, largely because the
two Russian fleets operating in the Pacific were forced by geography to use radio to communicate with Moscow instead of secure
teletype landlines. This allowed U.S. Navy listening posts in the Far East to easily intercept the radio traffic sent between
these headquarters and Moscow. There was also some success in reading the cipher systems used by the Soviet fleets in the
Baltic Sea, as well as the ciphers used by the Black Sea fleet and the Caspian Sea flotilla. By February 1949, U.S. Navy cryptanalysts
had produced more than twenty-one thousand decrypts of Soviet naval message traffic, which was almost double the number of
decrypts of Russian army traffic produced by ASA.
³⁹

A number of the Soviet air force’s operational ciphers were also quickly solved. In 1947, ASA cryptanalysts solved one of
the operational cipher systems used by the Soviet air force headquarters in Moscow to communicate with its subordinate commands
throughout the Soviet Union and Eastern Eu rope, as well as several variants of this system.
⁴⁰
In the Far East, U.S. Army cryptanalysts in Japan were reading the encrypted radio traffic of the Soviet Ninth Air Army at
Ussurijsk/Vozdvizhenka and the Tenth Air Army at Khabarovsk.
⁴¹

In room 2409 at Arlington Hall, a brilliant thirty-four-year-old former Japanese linguist and cryptanalyst named Meredith
Knox Gardner was making spectacular progress solving the ciphers that had been used during World War II by the Soviet civilian
intelligence service (its military counterpart was the GRU), then called the NKGB, to communicate with its
rezidenturas
in the United States. In later years, this work would be part of Venona program. In December 1946, Gardner solved part of
a 1944 NKGB message that gave the names of some of the more prominent American scientists working on the Manhattan Project,
the American war time atomic bomb program. The decrypt was deemed so important that army chief of staff Omar Bradley was personally
briefed on the contents of the message. Five months later, in May 1947, Gardner solved part of a message sent from the NKGB’s
New York
rezidentura
on December 13, 1944, which showed that an agent within the U.S. Army General Staff in Washington had provided the Soviets
with highly classified military information. Unfortunately, Gardner was not able to deduce anything further as to the agent’s
true identity from the fragmentary decrypt. By August 1947, new decrypts provided the first evidence that an extensive Soviet
spy ring was operating in Australia during World War II, which set off alarm bells in both Washington and London. Gardner
was able to report that the decrypts contained the cryptonyms of dozens, perhaps hundreds, of Soviet agents operating in the
United States, Australia, and Sweden during the war. But the report also clearly showed that Gardner had only made partial
headway into the Soviet codebook, and that the results of his work were still very fragmentary.
⁴²

Taken together, these decrypts opened up a wide array of Soviet military and civilian targets for exploitation by the information-starved
intelligence analysts in both Washington and London. An NSA historical monograph notes, “ASA in the post–World War II period
had broken messages used by the Soviet armed forces, police and industry, and was building a remarkably complete picture of
the Soviet national security posture.”
⁴³
This is confirmed by material obtained by researchers from the former KGB archives in Moscow, which reveals that the Anglo-American
COMINT organizations were deriving from these decrypts a great deal of valuable intelligence about the strength and capabilities
of the Soviet armed forces, the production capacity of various branches of Soviet industry, and even the super-secret work
that the Soviets were conducting in the field of atomic energy.
⁴⁴

Former NSA officials have stated in interviews that the first postwar crisis in which COMINT played an important role was
the 1948 Berlin Crisis.
⁴⁵
Ultimately, it was COMINT that showed that the Soviets had no intention of launching an attack on West Berlin or West Germany.
The initial stage of the Berlin Crisis was actually a Russian feint.
⁴⁶
COMINT also provided valuable data during the second part of the crisis, when on June 26, 1948, the Soviet’s cut off all access
to West Berlin, forcing the United States and Britain to begin a massive airlift to keep West Berlin supplied with foodstuffs
and coal for heating. Careful monitoring of Soviet communications indicated that the Russians would not interfere with the
airlift.
⁴⁷

Black Friday

During President Truman’s October 1948 nationwide whistle-stop train tour in his uphill battle for reelection against Governor
Thomas Dewey, the U.S. government was at a virtualstandstill. On the afternoon of Friday, October 29, just as Truman was preparing
to deliver a fiery campaign speech at the Brooklyn Academy of Music in New York City, the Russian government and military
executed a massive change of virtually all of their cipher systems. On that day, referred to within NSA as Black Friday, and
continuing for several months thereafter, all of the cipher systems used on Soviet military and internal-security radio networks,
including all mainline Soviet military, naval, and police radio nets, were changed to new, unbreakable systems. The Russians
also changed all their radio call signs and operating frequencies and replaced all of the cipher machines that the Americans
and British had solved, and even some they hadn’t, with newer and more sophisticated cipher machines that were to defy the
ability of American and British cryptanalysts to solve them for almost thirty years, until the tenure of Admiral Bobby Ray
Inman in the late 1970s.
⁴⁸

Black Friday was an unmitigated disaster, inflicting massive and irreparable damage on the Anglo-American SIGINT organizations’
efforts against the USSR, killing off virtually all of the productive intelligence sources that were then available to them
regarding what was going on inside the Soviet Union and rendering useless most of four years’ hard work by thousands of American
and British cryptanalysts, linguists, and traffic analysts. The loss of so many critically important high-level intelligence
sources in such a short space of time was, as NSA historians have aptly described it, “perhaps the most significant intelligence
loss in U.S. history.” And more important, it marked the beginning of an eight-year period when reliable intelligence about
what was occurring inside the USSR was practically non exis tent.
⁴⁹

The sudden loss of so many productive intelligence sources was not the only damage that can be directly attributed to the
Black Friday blackout. In the months that followed, the Anglo-American code breakers discovered that they now faced two new
and seemingly insurmountable obstacles that threatened to keep them deaf, dumb, and blind for years. First, there was far
less high-level Soviet government and military radio traffic than prior to Black Friday because the Russians had switched
much of their military communication to telegraph lines or buried cables, which was a simple and effective way of keeping
this traffic away from the American and British radio intercept operators. Moreover, the high-level Russian radio traffic
that could still be intercepted was proving to be nearly impossible to crack because of the new cipher machines and unbreakable
cipher systems that were introduced on all key radio circuits. The Russians also implemented tough communications security
practices and procedures and draconian rules and regulations governing the encryption of radio communications traffic, and
radio security discipline was suddenly rigorously and ruthlessly enforced. Facing potential death sentences for failing to
comply with the new regulations, Russian radio operators suddenly began making fewer mistakes in the encoding and decoding
of messages, and operator chatter disappeared almost completely from the airwaves. It was also at about this time that the
Russian military and key Soviet government ministries began encrypting their telephone calls using a newly developed voice-scrambling
device called Vhe Che (“High Frequency”), which further degraded the ability of the Anglo-American SIGINT personnel to access
even low-level Soviet communications. It would eventually be discovered that the Russians had made their massive shift because
William Weisband, a forty-year-old Russian linguist with ASA, had told the KGB everything that he knew about ASA’s Russian
code-breaking efforts at Arlington Hall. (For reasons of security, Weisband was not put on trial for espionage.)