State Department cipher machines and communications security in the early Cold War, 1944–1965

ABSTRACT

From 1944 the State Department attempted to improve its communications security by creating a Division of Cryptography and mechanising the encryption process. This article assesses the effectiveness of these reforms and shows that State’s new cipher equipment had cryptographic vulnerabilities. Moreover, the department was unable to maintain physical security at the Moscow embassy and through espionage and technical surveillance the KGB broke the ciphers and read American communications. The paper concludes by analysing the impact of this security failure, including the claim that intercepted messages influenced Stalin’s decision to approve the North Korean invasion of South Korea in 1950.

It has been well established that in the first four decades of the 20th century the State Department struggled to keep its correspondence secret. David Kahn and Christopher Andrew have shown that the department had weak codes and feeble physical and personnel security.¹ Communications security appeared not to be a priority for the department; Daniel Larsen recently examined cultural attitudes towards secrecy and diplomacy in the State Department during the Wilson administration and found that at the start of the First World War State exhibited ‘virtually no concern for the quality of its codes or the confidentiality of its communications’.² The United States was in effect conducting open diplomacy, with other great powers like Russia, France and Britain able to read American diplomatic telegrams. Even in the inter-war period, State Department cryptography was small scale and inert. The head of the Division of Communications and Records was responsible for creating and maintaining all of State’s cryptographic systems, and codes and ciphers were updated or replaced very infrequently.³

What has not been studied is whether State Department communications security noticeably improved with the coming of the Cold War. This lack of attention is probably due to the difficulty of accessing sources since many of the relevant documents of the State Department and the National Security Agency (NSA) are still classified, making research on the post-1945 period challenging. However, some of the secrecy was lifted in 2015 when the NSA released over 50,000 pages of official documents formerly held by the American cryptologist William Friedman.⁴ There remain gaps in the historical record but with this material it is possible for the first time to trace the development of State Department communications security in the early Cold War. So drawing on the Friedman archive, as well as other sources, this article will assess how effectively the State Department protected its communications between 1944 and 1965. It will show that the department made a concerted effort to break with the past and improve security by creating a Division of Cryptography and bringing into service a series of electro-mechanical cipher machines. The article will then evaluate the vulnerabilities of the new cipher equipment and examine the threat to their physical security from Soviet espionage and technical surveillance. The paper will conclude by discussing whether failings in State Department security benefitted the Soviet Union and affected Soviet decision-making towards Korea in 1950.

Creating the Division of Cryptography and mechanising encryption

At the start of the Second World War State Department communications security was still poor. To encrypt telegrams, the department relied on its A1, B1, C1, Gray and Brown code books and the M-138 strip cipher.⁵ Most of these manual codes had been in service for many years and in terms of cryptographic complexity they were far behind the cipher machines being developed by the US army and navy and by other countries such as Britain, Germany and Japan. Frank Rowlett, one of the greatest American military cryptologists of the Second World War, later described State’s code books as ‘antediluvian’.⁶ To make matters worse, American embassy security was negligent, enabling foreign intelligence services to steal or copy code books and recruit cipher clerks as spies. An undercover FBI agent visiting the Moscow embassy in 1940 found that the Russian ancillary staff had easy access to ciphers and documents.⁷ At night, the code room safes were left open and code books and telegrams strewn on a table. Embassy personnel were also having liaisons with local women who were believed to be controlled by Soviet intelligence. The weak cryptography and poor physical security allowed Germany, Japan, Italy and probably the Soviet Union to read American diplomatic traffic in the early stages of the war.⁸ The British had also solved the main American diplomatic cipher systems and in February 1942 Prime Minister Winston Churchill personally warned President Franklin Roosevelt that the State Department’s codes were vulnerable.⁹

The American authorities were in fact already aware that the State Department’s communications security needed to be greatly improved and modernised. A joint State-army-navy-FBI special committee had surveyed the department’s code and ciphers in May–June 1941 and highlighted the weaknesses in its security procedures.¹⁰ The committee urged that State collaborate with the War and Navy Departments to introduce machine encryption at the largest and most important American embassies. Army cipher machines were subsequently brought in to provide a secure communications link between Washington and London while navy machines were installed in Moscow and South American posts.¹¹ A second review was carried out by the army’s Signal Security Agency in late 1943 and it advocated more through going reform.¹² The agency pushed for the creation of a Cryptographic Security Group in the State Department with sufficient resources, facilities and technically competent staff to maintain cryptographic and physical security.¹³ It also recommended that the department ‘should make wider use of modern cryptographic machines’.¹⁴

These recommendations were soon put into effect. In September 1944, the Secretary of State set up a Division of Cryptography within the State Department which would be responsible for design, development, production and distribution of the department’s crypto material.¹⁵ The Division of Cryptography would also develop secure procedures for the handling of cryptomaterial and enforce their use. Commander Lee Parke of the US Navy was appointed Chief of the Division of Cryptography. Parke had considerable relevant experience; in the late 1930s, he was head of communications security for the navy’s OP-20-G signals intelligence agency and during the Second World War he rose to become Assistant Director of Naval Communications with responsibility for cryptographic security.¹⁶ Parke would lead the State Department’s Division of Cryptography for the next 19 years.

To mechanise encryption, State again turned to the US army and navy and adopted and adapted service cipher equipment though this process was not without setbacks and complications. The first device the State Department chose in 1944 was SIGFOY, a small, battery powered, rotor cipher machine designed for field use that had recently gone into production for the United States army. The State Department believed that SIGFOY could quickly meet its need for more secure encryption and ordered over 1,000 machines which it distributed to all American diplomatic posts between July 1944 and March 1945.¹⁷ This major acquisition turned out to be a mistake, however, for SIGFOY was badly designed and constructed.¹⁸ The machine made frequent encryption errors, was liable to break down and difficult to repair. It was loathed by its operators too – the American consul in Madras complained to the State Department that SIGFOY was ‘fantastically inefficient’ and had a ‘physical process of coding and decoding [that] could hardly be more awkward’.¹⁹ The army also experienced problems with SIGFOY and declared it obsolete in December 1945.²⁰ The State Department followed suit and withdrew SIGFOY from service in May 1946.²¹ It was an ignominious start to mechanised encryption for the State Department.

The United States army and navy did have more reliable cipher systems which on the face of it were better alternatives for the State Department. The most important of these was SIGABA, a sophisticated rotor cipher machine.²² Most rotor cipher machines at this time had rotors which moved in a single, mechanical stepping motion like an odometer but SIGABA’s five cipher rotors were electrically controlled and had unpredictable, irregular stepping which made hostile cryptanalysis far more difficult.²³ During the Second World War, the United States employed SIGABA extensively for military and navy communications yet the Axis powers failed to break any of the machine’s ciphers.²⁴ But precisely because SIGABA was so technologically advanced and secure, the army and navy saw it as too valuable to risk in exposed diplomatic posts after the war. The services did not even want to issue SIGABAs to their own service attachés in locations where there was a danger of physical compromise such as in the Soviet Bloc.²⁵

The army and navy instead developed two new rotor cipher machines, SIGROD and the CSP 1700, which were cryptographically nearly identical to each other and collectively known as the Combined Cipher Machine Mk II (CCM).²⁶ These were five rotor machines that made use of the SIGABA chassis but did not have its sophisticated rotor maze. The CCM was consequently less secure, but any physical compromise of the machine would not disclose the new cryptographic technology to an enemy. In the late 1940s the US army and navy began distributing the CCM to their attachés and overseas military posts. The State Department took a similar approach. Parke and the Division of Cryptography acquired 225 cipher machines from the US navy and modified them to create a relatively simple five rotor cipher machine, the MCB, which was close to the CCM in its encryption procedures.²⁷ In 1946, the State Department issued the MCB to many of its embassies and legislation, although the American embassy in Moscow only seems to have received the machine in January 1948.²⁸

A few American diplomatic missions, such as those in London and Paris, also had access to the army’s SIGTOT one-time teletype cipher machine and the State Department later developed its own version of SIGTOT, known as MOT.²⁹ In theory, these devices were highly secure because their teletype key tapes were only used once and then destroyed. They were also exceptionally fast for they were capable of on-line encryption. Cipher machines normally operated off-line, with encipherment and decipherment separate processes to transmission, but with on-line encryption a plain text could be typed into the cipher machine and simultaneously encrypted and transmitted. At the receiving end messages were automatically decrypted and typed out by a teleprinter. However, despite having these advantages of speed and security, the use of SIGTOT and MOT was severely constrained because they were not suitable for network communications and required massive amounts of teletype tape that had to be securely stored and deposed of after use, a challenge for many embassies with a limited amount of space. Moreover, the MOT was prone to mechanical failure. In 1955, the State Department refused to issue it to the American embassy in Tehran because the device needed ‘fairly constant preventative maintenance’.³⁰ So in the late 1940s and early 1950s the MCB would be the mainstay of State Department machine encryption.

The State Department believed that with the MCB, SIGTOT and MOT it had eliminated the cryptographic weaknesses of the past and secured American diplomatic communications. In a Washington Post article in 1948 the department revealed that the encryption of messages to its embassies ‘is now handled by machines rather than by hand, and machine codes are subject to quick changes and to complexity of uses which make it extremely difficult if not impossible for an important message in code to be read by foreign agents’.³¹ During Senate hearings in 1951 a State Department representative recognised that there had been considerable criticism of the department’s codes in the Second World War but reassured senators that ‘[w]e have taken a lot of interest in this and we feel that we have a security code, as secure as there is in the world’.³²

Weaknesses in the cipher machines

Unfortunately, this confidence was misplaced for there remained significant problems with State Department communications security. The new cipher machines had inherent weaknesses and control of the American embassy in Moscow was very still poor, with the State Department unable to prevent Soviet espionage and technical surveillance. The flaws in the cipher machines became first apparent in 1951. The CIA was also an operator of SIGTOT and the agency discovered that the machine produced compromising electro-magnetic emissions when encrypting which could reveal the contents of messages.³³ Alerted to the problem, the State Department in March 1951 had to warn its diplomatic missions in London, Paris, Moscow, Frankfurt and Vienna that the plain text of SIGTOT messages could inadvertently be conducted down the signal line with the encrypted text.³⁴ The State Department instructed the posts to stop using SIGTOT wherever possible and cease operating one-time tape cipher machines in on-line mode, which considerably reduced their speed.

The United States then found that the CCM and MCB cipher machines were also less secure than originally thought. In December 1951, an investigation by American and British experts uncovered vulnerabilities in the CCM (which in NATO use had been given the code name AJAX).³⁵ Details of this discovery are still classified but two contemporary documents of the American Armed Forces Security Agency (AFSA), which at that time was responsible for service communications security, have the titles ‘Possible Cryptanalytic Compromise of the Combined Cipher Machine’ and ‘Brief History of the AJAX Crisis of Dec 51’.³⁶ The British signals intelligence agency, GCHQ, advised its Canadian counterpart that the ‘[n]ature of insecurity of CCM is newly discovered exhaustion attack … US authorities agree with us on insecurity’.³⁷ As an immediate response, the Americans had to modify the CCM and change its operating procedures, which made the device more time consuming and unwieldy to use.³⁸ Even with these emergency countermeasures, the AFSA felt that it was urgent to replace the CCM. This all had implications for the State Department’s MCB machine. The Director of the AFSA explained in June 1952 that:

The State Dept. is now using a cipher machine which is essentially the cryptographic equivalent of AJAX … All attacks which work on AJAX … work on the CSP 2200 [MCB]. It is considered imperative therefore that the State Dept. proceed at once to improve their cryptographic position.³⁹

In 1951–52 then, there was something of a crisis in American cryptography with the MCB, CCM and SIGTOT all found to have vulnerabilities. The State Department responded by bringing into service a successor to the MCB, the MEC. Designed by Parke and the Division of Cryptography, the MEC was a rotor cipher machine with electrical stepping for its rotors, like SIGABA, but with a different rotor control maze.⁴⁰ According to an NSA history, Parke had sought to ‘adopt as much of the SIGABA logic as was needed to achieve sound security’ while at the same time ‘avoid risking the SIGABA details in hazardous locations in which the Department of State had to use its cryptographic machines’.⁴¹ Compromise of the new MEC machine would therefore only compromise the principle of electrical stepping, not the embodiment of it found in SIGABA.

Through the 1950s the State Department issued the MEC to its diplomatic posts. It was installed in the American embassy in London in January 1953 and then over the next two years rolled out to missions in Western Europe, the Middle East, the Far East and Latin America.⁴² It took longer to equip the more exposed posts behind the Iron Curtain and Moscow, Bucharest, Budapest, Prague and Warsaw only received the MEC in February 1959, replacing their MCB machines.⁴³ The MCB was discontinued worldwide in July 1959.⁴⁴ In purely cryptographic terms, the MEC was more secure than the MCB but it was difficult to use. Rather than build wholly new code machines, the State Department appears to have created MECs by modifying existing cipher equipment and the machinery was starting to show its age. A retired State Department cipher clerk later characterised the MEC as ‘cumbersome, noisy, slow and prone to failure if not properly maintained’.⁴⁵

Embassy attacks, espionage and bugging

Alongside these cryptographic challenges, the State Department had to protect the physical security of its cipher machines against a variety of overt and covert attacks. When the North Korean army invaded South Korea in June 1950 the American embassy in Seoul was quickly overrun but the marine guards were able to destroy the embassy’s code machines with thermite just before evacuating.⁴⁶ In Taiwan, American security was less successful.⁴⁷ After a court martial acquitted an American soldier in May 1957 of killing a Taiwanese civilian, an angry mob stormed the US embassy in Taipei and managed to break into the code room. The room was protected by a thick steel door, but its walls were only made of chicken wire, studs and plaster and the rioters smashed through using sledgehammers. They ransacked the room and the cryptographic safe and while the embassy’s two MCB cipher machines were not damaged, 100 rotors were stolen. Many of these were later found strewn over the embassy grounds by the departing protestors. The State Department assumed that the cipher systems had been compromised and immediately ordered all Far Eastern posts to temporarily switch to manual one-time code pads for encryption. The next day couriers with replacement cryptographic material (most likely new rotors and keys) were sent out from Washington.

The Taipei embassy attack was dramatic and disruptive but the most serious breaches of physical security in this period came from Soviet espionage. In the late 1940s and early 1950s the KGB was able to suborn in succession three US army cipher staff stationed at the American embassy in Moscow and gain intelligence on the crypto systems.⁴⁸ Its first informant was Sergeant James McMillin, a military cipher clerk who defected to the Soviet Union in May 1948 in order to marry his Russian girlfriend, Galina Biconish.⁴⁹ Although this appears to have been a genuine relationship, the KGB had encouraged Biconish to target McMillin and facilitated his defection.⁵⁰ In return, McMillin provided the KGB with documents and explained how the embassy cipher machines worked, describing the installation of the rotors and their position changes according to the key list.⁵¹ McMillin also told the Soviets about the personalities and the daily routines of the other cipher clerks, which could have helped future KGB recruitment.

The information from McMillin was valuable, but according to former KGB officer Sergey Kondrashev, who was involved in the entrapment operation, it was insufficient to break the American ciphers.⁵² Moreover, the US authorities moved quickly to change all their codes after McMillin’s defection. They assumed that he had compromised the CCM system in Moscow which was used by most American military attachés and major army installations in Europe and the Middle East.⁵³ The State Department was also affected, for since March 1948 State and the army had operated a combined cryptocentre in the embassy, sharing personnel and facilities. Replacement rotors and keys were immediately sent out. The Washington Post reported that the State Department had been forced to spend $80,000 on changing its cipher machines all around the world as a result of McMillin’s defection.⁵⁴

However, although the State Department and US armed forces took swift cryptographic countermeasures, human security in Moscow remained a weak point and a few months later, in early 1949, the KGB was able to recruit another military cipher clerk in the American embassy.⁵⁵ This agent, who was codenamed ‘Jack’ by the KGB and never identified by American counter-intelligence, was also involved in a relationship with a Russian woman. But unlike McMillin, Jack was willing to stay in place and sell the Soviets information about the cipher systems. He had a series of secret meetings with a KGB signals intelligence expert who asked detailed technical questions and gave him tasks to perform on the cipher machine. Jack also provided a broken rotor and a key schedule. By the time he returned to the United States in late 1949 the KGB had paid him $100,000 for his work, a considerable sum by contemporary standards.

Kondrashev claimed that Jack’s assistance enabled the KGB to build a copy of the cipher machine used by the military attaché (most probably the SIGROD version of the CCM) and read the traffic from the embassy for as long as the keys supplied by Jack remained valid.⁵⁶ Through this break into the machine, the Soviets were also able to decrypt military traffic between Washington and other posts abroad. Some supporting evidence for Kondrashev’s claims comes from the testimony of Stig Wennerstrom, the Swedish air attaché in Moscow between 1949 and 1951. Wennerstrom secretly worked as a spy for Soviet military intelligence, the GRU, but on occasion, he also passed on information to the American air attaché.⁵⁷ The GRU discovered his double dealing when it decrypted a telegram from the American embassy in Moscow that mentioned him by name. Wennerstrom later testified to a Senate inquiry that:

In a radio report, they [the embassy] used my name as well as a cipher that the Soviets were able to break … .Radio messages from the radio station in the American embassy were monitored and the ciphered material was assembled and efforts made to decode it, which was possible at times … I know that on certain occasions also the Soviets had been able to obtain the key to codes from the American Embassy.⁵⁸

Kondrashev did not disclose whether the intelligence from Jack also enabled the KGB to read the ciphers of the State Department’s MCB machine although it was similar to CCM and had the same cryptographic weaknesses. The breakthrough against the MCB possibly came later, in 1953, when the KGB recruited yet another source in the embassy, US army Sergeant Dayle Smith.⁵⁹ Smith was a cipher machine mechanic assigned to the military attaché, but he also had access to the State Department crypto equipment. In exchange for money, he gave the Soviets sensitive technical information. According to Yuriy Nosenko, a KGB defector to the United States in the early 1960s, Smith described to the Soviets the operation of the State Department cipher machines and supplied the daily settings. Nosenko emphasised to his CIA debriefers the importance of Smith, saying that ‘Thanks to his help they [the KGB] were able to read your State Department codes’.⁶⁰ It does seem plausible that by the mid-1950s, the KGB could read at least some State Department traffic for intercepted American embassy telegrams were distributed to the Soviet leadership during the 1956 Suez Crisis.⁶¹

Yet there was another factor at play: Soviet technical surveillance of the embassy. The American embassy in Moscow was poorly protected against bugging and the KGB was highly proficient at planting covert surveillance devices. In May 1953, the United States moved the embassy chancery to another building across town and set up a new joint State Department-service attaché code room. But when a Regional Security Officer inspected the code room in October 1954 he found that it was not sound proofed and had French doors opening out onto a balcony above a street.⁶² The doors were sometimes propped open in the summer to provide ventilation. The appalled security officer warned in his report that the Moscow embassy code room ‘cannot be equalled in insecurity by any Communications Center in a United States installation in Europe’.⁶³

Yet the problem of lax security was actually even worse than he realised. Before the Americans took occupancy of their new chancery Soviet workmen had remodelled the building and State Department security failed to properly supervise the works.⁶⁴ The Soviets covered the building with tarpaulins, blocking view of the renovations from outside, and insisted on prior appointment for any site inspections. When Americans did come on site they were only allowed to do visual inspections and were always accompanied by the Soviet architect. All visits by US personnel were prohibited for two to three weeks in early March 1953. While American visitors were kept away, the KGB embedded over 50 microphones in the chancery building, concealing them in walls behind radiators in all the key rooms, including the embassy code room. Later in the 1950s, the Americans established separate State Department and service attaché code rooms but both of these rooms already had microphones in them.⁶⁵

The microphones allowed the KGB to do more than just eavesdrop on the conversations of cipher clerks, for as the Americans slowly discovered in the 1950s, the sounds produced by cipher machines could expose the content of messages and reveal the cryptographic system. A later NSA report on the Moscow embassy bugging explained that:

… teleprinters and cryptographic equipments do not run silently; they emit acoustical and electromagnetic energy … The sounds emitted by the machinery involve minute differences in amplitude, frequency, and timing as different letters and characters are processed by the equipment. Relatively insensitive pick-up devices can detect these differences if they are placed at fairly close range to the equipment as was the case in each of the Moscow code rooms. When these sounds are recorded and analyzed the plain text of messages can be reconstructed.⁶⁶

The NSA believed that by exploiting the cipher machines’ acoustic emissions ‘[i]t was technically feasible for the Soviets to have recovered the plain text of the messages encrypted and decrypted by machines in these coderooms’.⁶⁷ Furthermore:

… the sounds made by these equipments reflect the internal mechanical workings of the cipher machine; these sounds can be recorded, analyzed, and the crypto system itself could have been reconstructed. If this did occur, not only the messages processed in Moscow but also those messages processed by other posts using the same machines and the same cryptomaterial could have been lost’⁶⁸

In 1953 then, poor State Department security would have enabled the Soviets to mount a two-sided attack on the MCB, obtaining information from Dayle Smith while monitoring and analysing the machines’ compromising acoustic emissions.

After the MEC replaced the MCB at the American embassy in Moscow in February 1959 the Soviet technical surveillance team had to master the new cipher machine. Nikolai Andreev, a KGB officer involved in the surveillance operation, later recalled that the ‘main difficulty was to find the “weaknesses” of the electromechanical encoder at the US Embassy in Moscow; to determine which parts of their [the Americans] machine generate spurious emissions’.⁶⁹ This seems to have been done fairly quickly, for by 1959 the KGB could again read encrypted messages from the embassy.⁷⁰ Andreev and his team received the Lenin Prize for this feat.⁷¹

The American authorities were unaware of Andreev’s breakthrough, but by the early 1960s, there was growing alarm in Washington about State Department communications security. In April 1960, the NSA warned Parke that the department’s cipher machines did not meet acceptable security standards and should be replaced at the earliest possible date.⁷² It is not clear what the NSA’s concerns were but the State Department itself was exercised about the possible dangers posed by bugging and technical surveillance. John Hanes, the head of the department’s Bureau of Security and Consular Affairs, lamented in a memorandum in 1960 that because of major advances in surveillance technology and computers ‘we are under constant apprehension that the enemy … may be overhearing our conversations and reading our encrypted messages’.⁷³ On 28 September 1960, the State Department suddenly ordered its embassies in Moscow, Warsaw, Prague, Bucharest and Sofia to encrypt with manual one-time pads all future telegrams classified as top secret and secret.⁷⁴ This indicated a considerable loss of faith in the MEC which had only been installed in the East European embassies the previous year. The State Department might have been reacting to comments made by the Soviet leader Nikita Khrushchev at a meeting with the Iranian chargé d’affaires in August, which suggested that Khrushchev knew the contents of cables sent to the American embassy in Moscow.⁷⁵

Reverting back to manual encryption in the Soviet Bloc embassies could only be a temporary expedient and the State Department hurriedly sought other ways to mitigate the threat from technical surveillance. One approach was to install shielding around cipher machines.⁷⁶ In October 1960, the service attaché cipher machine in the Moscow embassy was placed in a special sound proofed box.⁷⁷ Going a step further, an acoustically shielded room was installed in the embassy in December 1962 to house the State Department code machines.⁷⁸ This protection would have prevented Andreev’s KGB surveillance team from detecting and reading any more compromising emissions from the embassy’s cipher machines. But shielded communications rooms were expensive and difficult to install and by 1964 they had only been put in eight American diplomatic posts.⁷⁹

The other approach taken by the State Department was to ask the NSA to create a new cipher machine that could replace the MEC and be as free as possible from compromising emissions. Originally, the State Department had wanted the MEC’s replacement, the KW-1, to be available by the start of 1963 but in November 1960, it advised the NSA that it needed the machine at least a year earlier and urged that ‘the greatest priority possible … be accorded to the development of replacement equipment capable of resisting all known penetration methods’.⁸⁰ Unfortunately, this new completion date could not be met and the KW-1 was only ready for production in autumn 1962.⁸¹ The State Department then encountered resistance from an economy minded Congress which wanted to slash a $4.86 million budget request for 400 KW-1s and associated teletypewriters down to just $1.5 million.⁸² In early October 1962 department officials had to plead their case before the Senate Appropriations Committee and publicly reveal the deterioration in State’s communications security. They admitted that because of threats posed by recent technological advances ‘[i]t has become highly important … that outmoded communication equipment at overseas posts be replaced at the earliest possible date. The equipment now in use is many years old and is subject to possible compromise by foreign governments’.⁸³ The State Department also justified the expenditure on operational grounds, arguing that its current cipher machines were ‘worn out and obsolete’ and ‘subject to frequent breakdowns and time-consuming repairs’.⁸⁴

The CIA takes over

Three weeks later, the Cuban Missile Crisis transformed the situation. It is well known that during the crisis President John Kennedy and Khrushchev found it difficult to quickly communicate with each other and that this experience inspired the creation in 1963 of the Hotline, a dedicated teleprinter link between Moscow and Washington. But the crisis also hammered home to Kennedy the need to generally modernise and improve the State Department’s telecommunications system, for State proved unable to cope with the high volume of urgent traffic between Washington and embassies in October 1962. For example, a crucial 12 part message from Kennedy to other heads of government was sent through State Department channels but failed to reach many posts or arrived missing three parts, resulting in several American allies being caught unawares when Kennedy gave his televised speech on 22 October announcing a blockade of Cuba.⁸⁵ The fault mostly lay with the State Department’s antiquated and fragmented telecommunications network, but time-consuming encryption and decryption operations aggravated delays. On 24 October, the Executive Committee of the National Security Council broke off its discussion of the on-going crisis to consider the communications issue.⁸⁶ Kennedy was briefed that:

… one problem is that all of the Latin American enciphered telegraph facilities are made up of what we call off-line facilities, so that it takes a considerable amount of time to get an enciphered message from the transmitter to the receiver, and they can’t be use for two-way telegraph conferences.⁸⁷

The president was exasperated and he set up a National Security Council sub-committee headed by William Orrick, the Under Secretary of State for Administration in the State Department, with orders to solve the immediate communications problem in Latin America and to draw up plans for an integrated national communications system that could bring together the networks of the State Department, CIA and military.⁸⁸

Fortunately, there was on hand an advanced, on-line cipher machine which could be quickly issued to the embassies in Latin America. This was the KW-26, a completely electronic cipher machine which the NSA had developed and brought into service for the American armed forces in 1957.⁸⁹ The KW-26 was a generation ahead of the State Department’s MEC and represented a major technological leap forward. It encrypted messages with an internal electronic key generator and since it had no rotors or other mechanical moving parts, it produced fewer compromising emissions. For reasons that are unclear, the State Department had not adopted the KW-26, but the CIA had used the machine in its overseas stations since 1958.⁹⁰ The agency had spare machines available and it was directed to deploy 89 KW-26s to Latin American and other diplomatic posts by the end of November 1962.⁹¹

The KW-26 also featured prominently in the Orrick Committee’s deliberations on how to set up a national communications system. The aim was to create joint State Department-CIA code rooms in embassies with common use of on-line KW-26 machines. But this posed a problem for the CIA as the KW-26 automatically decrypted and typed out incoming messages and anyone in the code room would be able to see the clear text, whether they were State or CIA.⁹² The agency argued that it had to maintain the privacy of its communications because otherwise they could reveal secret intelligence sources and clandestine techniques. This meant that CIA personnel would have to staff the consolidated communications centres. Although Orrick was sceptical at first the CIA’s stance was ‘not negotiable’ and it was incorporated into the committee’s planning.⁹³ Where possible, embassy code rooms would be co-located in a single communications centre with the CIA operating the cryptographic equipment and teletype terminals.⁹⁴ These consolidated centres would be equipped with KW-26 on-line cipher machines. Embassies would also have the new KW-1 cipher machine so the State Department could protect its privacy and encrypt any highly sensitive telegrams before they were passed on to CIA for on-line encryption and transmission. A few embassies and most consular establishments would have just the KW-1, presumably because of their low volume of traffic.

This plan was largely implemented in 1963. The CIA transferred one of its leading communications specialists, John Coffey, to the State Department for two years to be Deputy Assistant Secretary of State for Communications and carry out the reforms.⁹⁵ In March 1963, a new State Department Office of Communications was formed with a Division of Communications Security.⁹⁶ State’s cryptographic staff were reassigned to the new organisation, although Lee Parke chose to resign in February 1964.⁹⁷ A Diplomatic Telecommunications Service was also established with combined State-CIA communication centres in many American embassies under joint State-CIA control.⁹⁸ The necessary funding was found to equip these centres with more KW-26s and provide fast, secure, on-line encryption. The KW-1, however, turned out to be a dud despite its years of development. The machine performed badly in production testing in 1963, corrupting many letters in messages.⁹⁹ The State Department had to abandon the device and instead purchase a basic one-time tape cipher machine, the HW-28, to give diplomatic posts an off-line encryption capability.¹⁰⁰ The HW-28s were issued to posts in 1965 and the State Department’s vulnerable MEC cipher machines were finally withdrawn from service across the network.¹⁰¹

The Cuban Missile Crisis thus brought about major and long overdue improvements in American diplomatic cryptography. It also led to much greater CIA involvement in State Department communications. A retired State Department official, Nuel Pazdral, later recalled that after the missile crisis:

… new encrypting gear was budgeted. The Central Intelligence Agency took over a large part of this because they had these machines. It was called a KW26 … It was pretty much space age gear for its day and the Central Intelligence Agency was the only agency that had many of these machines. So they then moved into our communication picture in the State Department for the first time. And ever since then we have had the system which we had then, which is basically that we sort of massage the data and then pass it along to Agency folks who send it onward.¹⁰²

Victor Marchetti, a former CIA officer, described a similar relationship in 1974, writing that:

… it should be understood that CIA communication clerks handle nearly all classified cables between American embassies and Washington – for both the CIA and the State Department. To have a separate code room for each agency in every embassy would be a wasteful procedure, so a senior CIA communications expert is regularly assigned to the administrative part of the State Department in order to oversee the CIA’s communicators who work under State cover.¹⁰³

In effect, between 1962 and 1965 the State Department had to cede much of its communications security role to the CIA.

Conclusion

Reviewing the period between 1944 and 1965 it is hard to escape the conclusion that the State Department failed to adequately protect its communications security. The Division of Cryptography did mechanise the encryption process by introducing the MCB, MOT and MEC cipher machines and although SIGFOY and the KW-1 were fiascos, State Department cryptography was undoubtedly far stronger in the early Cold War than it had been in 1939. The level of encryption and communications security was probably good enough to protect American diplomatic cables against attack from many foreign intelligence agencies. Crucially though, it was insufficient defence against the main enemy, the Soviet Union, and the KGB was able to read State Department and military attaché traffic at critical moments in the early Cold War. Despite all the high hopes around the creation of the Division of Cryptography and mechanisation, by the early 1960s the State Department was unable to provide fast, secure encryption and it had to be rescued by the CIA, just as it had been rescued by the American army and navy in 1944.

Two factors stand out in this failure. Firstly, the State Department did not keep up with the rapid advances in cipher machine technology from the mid-1950s. The Division of Cryptography may have had insufficient personnel and resources to do this; it only had 31 Cryptography Staff in 1961 and appears to have struggled to get funding from Congress.¹⁰⁴ Yet even so, it is hard to understand why State did not adopt the KW-26 in the 1950s, like the CIA. Secondly, the State Department did not maintain physical security in the American embassy in Moscow in the late 1940s and early 1950s, and this gave opportunities for the KGB to install an extensive technical surveillance system and suborn cipher personnel. In this aspect, the State Department performed worse than the foreign services of some of America’s allies. The British embassy in Moscow was also bugged by the Soviets but the Foreign Office managed to prevent its cipher staff from being recruited by the KGB.¹⁰⁵ Generally, there does not seem to have been sustained attention and commitment to all aspects of communication security in the State Department, in spite of the best efforts of Parke and the Division of Cryptography.

What remains to be determined is whether State’s flawed communications security gave the Soviets an advantage in the Cold War. Russian sources are largely quiet about the duration and impact of the KGB’s break into the Moscow embassy’s cables but we do have contemporary American damage assessments. Acting on information from the KGB defector Nosenko, the State Department discovered the bugging system in the embassy in 1964 and the President’s Foreign Intelligence Advisory Board (PFIAB) commissioned the United States Intelligence Board (USIB) to lead a multi-agency investigation.¹⁰⁶ The NSA’s technical assessment was that the microphones could have enabled the Soviets to read all of the State Department’ telegrams with Moscow from 1953 until October 1960, when the embassy switched to one-time pad manual encryption for top secret and secret messages.¹⁰⁷ Once the shielded room was installed in the embassy in December 1962 all State Department traffic should have been protected. State Department cables with other East European posts were also likely ‘to have been compromised during 1952–1959 through cryptomachine information derived at Moscow’.¹⁰⁸ The military attachés were similarly affected. Attaché traffic processed in Moscow might have been read up to October 1960, when the cipher machine was placed in a sound proofed box. Since the microphones could have disclosed the workings of the CCM’s cipher system, between 1952 and 1954 ‘all traffic in the entire attache net which included Moscow could have been compromised’.¹⁰⁹

These were severe, prolonged breaches of American communications security yet in its damage assessment the State Department downplayed the likely diplomatic impact.¹¹⁰ The department reviewed telegraph traffic with the Moscow embassy during several Cold War crises and periods of superpower negotiation and concluded that while the Soviets may have gained some small tactical advantages from reading these telegrams, in most cases there was no evidence that damage had been done to American foreign policy interests. Compromised messages during the Korean War and the 1958–59 Berlin Crisis might even have benefitted the United States by revealing American resolve. Some members of the PFIAB criticised this assessment seeing it as the State Department ‘seeking to sweep unpleasant matters under the rug’ and the final USIB report seems to have tempered State’s optimism.¹¹¹ The board noted that while there was no indication of Soviet action detrimental to the United States based on the compromised information, ‘it must be concluded that due to the extensive period of penetration … the cumulative effect had resulted in serious damage to the U.S’.¹¹²

It does appear that the intercepted State Department communications were a prized source of intelligence for the Soviet leadership. Nosenko told the CIA that the KGB regularly sent Khrushchev and the Central Committee reports on its intercepts of American embassy telegrams.¹¹³ According to Nosenko, when the source was lost, the Central Committee exerted considerable pressure on the KGB ‘for continuation of the information formerly obtained in this manner’ and this led the KGB Chairman to demand ‘maximum effort from all KGB officers concerned with the recruitment of [American] code clerks’.¹¹⁴ Moscow embassy traffic published in the Foreign Relations of the United States document series contains material that would surely have been of interest to Khrushchev, such as two State Department telegrams to Moscow in May 1956 which reported that the CIA had covertly obtained a copy of his ‘Secret Speech’ and was considering the best way to leak it to a global audience.¹¹⁵ Further research into State Department and military attaché correspondence is needed to fully understand the scale and type of intelligence the Soviets may have collected between 1953 and 1962 from the bugging system.

It is also possible that an earlier breach of Moscow embassy security, the recruitment of the cipher clerk Jack by the KGB in 1949, had a major impact on superpower relations and the Cold War. The information and cipher keys Jack provided enabled the Soviets to read American military communications between Washington and other posts apart from Moscow.¹¹⁶ After the end of the Cold War, Kondrashev, Jack’s KGB handler, claimed that some of this traffic had helped convince Soviet leader Josef Stalin to approve North Korea’s invasion of South Korea in 1950.¹¹⁷ Viktor Abakumov, the Soviet Minister for State Security, would personally give Stalin transcripts of the deciphered American military messages and Abakumov confided to Kondrashev that these intercepts had been ‘especially persuasive for Stalin’.¹¹⁸ They gave the Soviet leader the impression there was little danger of direct conflict with the United States if the Soviets supported the North Korean venture. According to Abakumov, that ‘was why Stalin finally removed his objection to the North Koreans’ long standing plans to invade’.¹¹⁹

This was a big claim to make and it could just have been boastful hyperbole from Kondrashev. However, in 2020 the historian Sergey Radchenko reported the discovery of a Chinese document that gave more credence to Kondrashev’s story.¹²⁰ The document was a record of talks in 1956 between the Chinese leader Mao Zedong and Anastas Mikoyan, First Deputy Chairman of the Soviet Council of Ministers. At the meeting Mao asked Mikoyan why Stalin had decided to give the go head to Kim Il Sung’s invasion. Mikoyan replied that it was because Soviet intelligence had intercepted telegrams from General Douglas MacArthur in Japan to the United States which indicated that the Americans would not get involved if a war broke out in Korea. There does seem here a possible connection with the KGB operation in Moscow, but it is not clear whether MacArthur’s messages would have been encrypted by the same type of cipher machine, the SIGROD version of the CCM, which Jack appears to have compromised. MacArthur’s Far East Command had started using SIGROD in January 1948, but it also operated SIGABA in its major headquarters and it is likely that any cables from MacArthur would have been encrypted by the more secure SIGABA, which as far as we know the Soviets never broke.¹²¹ More research is needed to elucidate this topic and for now any connection can only be speculative. Nonetheless, the Mikoyan document does raise the intriguing possibility that the Korean War, one of the bloodiest wars of the Cold War, was partly caused by poor State Department embassy security.

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Additional information

Notes on contributors

David Easter

David Easter is a Senior Lecturer in the Department of War Studies at Kings College London. His research interests are intelligence, the Cold War, and conflict in the Middle East and South East Asia. He has written extensively on Western and Soviet signals intelligence, communications security, American and British covert action and Soviet policy towards Syria and Indonesia under Nikita Khrushchev.

Notes

1. Kahn, The Codebreakers, 488–501; Andrew, The Secret World, 458, 468, 532, 539, 584.

2. Larsen, “Creating an American Culture,” 107.

3. Ibid., 109, 126–130; Kahn, The Codebreakers, 488–493.

4. NSA, William Friedman Collection of Official Papers, https://www.nsa.gov/Helpful-Links/NSA-FOIA/Declassification-Transparency-Initiatives/Historical-Releases/Friedman-Documents/

5. NSA, Friedman Collection, A67293, Letter Stimson to Secretary of State, Enclosure B, 22 January 1944; Kahn, The Codebreakers, 495.

6. NSA, Oral History Interview, NSA-OH-1976-1-10 Rowlett.

7. Andrew and Gordievsky, KGB, 240.

8. Alvarez, “Axis Sigint collaboration,” 6–7, 10–11; Alvarez, “Diplomatic solutions,” 171; Andrew and Gordievsky, KGB, 239–240, 243; Andrew, The Secret World, 591, Kahn, The Codebreakers, 493–501.

9. Ferris, Behind the Enigma, 164; Andrew, The Secret World, 638–639.

10. NSA, Friedman Collection, A67132, Report of Special Committee to Investigate Security of State Department communications, 26 June 1941.

11. Ibid., A67130, Notes on Conference between representatives of the Signal Security Agency and the State Department, 19 November 1943; A67270, Letter Corderman to Goodrich, 6 March 1944.

12. Ibid., A67130, Notes on Conference between representatives of the Signal Security Agency and the State Department, 19 November 1943; A67295, Draft report on cryptographic systems used by the State Department, 2 December 1943.

13. Ibid., A67293, Letter Stimson to Secretary of State, Enclosure A, 22 January 1944.

14. Ibid.

15. NSA, History of the Signal Security Agency, Volume 1, Organisation, Part 1, 1939–1945, 13 April 1948; NSA, Friedman Collection, A67035, Letter ASA80 to ASA 82, Enclosed memorandum ‘Establishment of Joint Crypto-Centers’, 29 August, 1947; The National Archives at College Park, Maryland (NARA), Record Group 59, State Department Central Decimal File, 1955–59, Box 490, Letter Henderson to Hoover, 22 July 1956.

16. Maffeo, U.S. Navy Codebreakers, 124–125; NARA, RG 59, 1955–59, Box 490, Letter Henderson to Hoover, 22 July 1956; “Lee Parke Resigns; Mr Rusk Cites his Service Record,” Department of State News Letter, No. 35, March 1964, https://www.google.co.uk/books/edition/Department_of_State_News_Letter/rQmEPFsz7BgC?hl=en&gbpv=0

17. NSA, History of the Signal Security Agency, Volume 1, Organisation, Part 1, 1939–1945, 13 April 1948.

18. Kruh, “Cipher Equipment”, 148.

19. NSA, Friedman Collection, A69358, Letter Bower to Shaw, 17 November 1944.

20. NSA, History of the Army Security Agency: Post War Transition Period: 1945–1948, 7 April 1952.

21. NSA, History of the Army Security Agency, Volume 1, Organisation, Part 1, 1939–1945, 13 April 1948.

22. The navy version was called the Electric Cipher Machine or ECM.

23. Mucklow, SIGABA/ECM II, 16–18, 29–30.

24. Ibid., 26, 22–24.

25. NSA, History of the Army Security Agency: Post War Transition Period, 1945–48, 7 April 1952.

26. The original Mk 1 versions of the CCM were adaptors in World War Two to enable SIGABA and the British Typex machine to communicate. See NSA, Friedman Collection, A523210, ‘History of Converter M-134-C, Volume 3’, not dated.

27. House of Representatives, 80th Congress, Hearings before the Subcommittee of the Committee on Appropriations, Department of State Appropriation Bill for 1948, 19 March, 1947, 356.; NSA, History of the Signal Security Agency, Volume 1 Organisation, Part 1, 1939–1945, 13 April 1948; NSA internal history, ‘A History of U.S Communications Security Post World War II’, not dated, www.governmentattic.org

28. NSA, History of the Signal Security Agency, Volume 1 Organisation, Part 1, 1939–1945, 13 April 1948; NARA, RG 59, 1945–49, Box 509, Letter 42, Moscow to State Department, 8 January 1948.

29. NARA, RG 59, 1945–49, Box 511, Letter Parke to Chapin, 11 October 1945; Telegram 5771, State Department to Paris, 11 December 1945; Telegram 550 State Department to Moscow, 17 May 1948; RG 59, 1950–54, Box 497, Telegram 492 State Department to Pusan, 4 February 1953.

30. NARA, RG 59, 1950–54, Box 498, Letter CA-4005 State Department to Tehran, 20 December 1955.

31. ”State Dept. Details Safety Precautions,” The Washington Post, 9 December 1948, 3.

32. Senate, 82nd Congress, Hearings before the Subcommittee of the Committee on Appropriations, Part 1, Departments of State, Justice, Commerce, and the Judiciary Appropriations for 1952, June 6, 1951, 1169.

33. Easter, “The impact of Tempest,” 2–3.

34. NARA, RG 59, 1950–54, Box 493, Letter State Department to Paris, London, Moscow, Frankfurt and Vienna, 8 March 1951.

35. NSA, History of the Army Security Agency and Subordinate Units, Fiscal Year 1952, Volume 1, Administration, Assistant Chief of Staff, G2, 1955; The British National Archives, FO 371/96594, Folder title ‘Insecurity of the Combined Cypher Machine. Investigation by US and UK experts show that security of CCM is insecure’ 21 December 1951.

36. NSA, Friedman Collection, A71238, AFSA Mail Log, not dated.

37. O’Neil, Kevin and Ken Hughes, History of the CBNRC, Volume V, Chapter 20, 12, No location given, 1987, Canadian Foreign Intelligence History Project database, September 8, 2022, https://carleton.ca/csids/canadian-foreign-intelligence-history-project/

38. Aldrich, Espionage, Security and Intelligence, 51–53.

39. NSA, Friedman Collection, A272413, Letter Canine to Parke, 24 June 1952. For evidence that CSP 2200 was the naval designation of the MCB see NSA, History of the Signal Security Agency, Volume 1 Organisation, Part 1, 1939–1945, 13 April 1948.

40. Ibid.

41. NSA internal history, “A History of U.S Communications Security Post World War II,” not dated, June 3, 2023, www.governmentattic.org

42. NARA, RG 59, 1950–54, Box 497, Letter State Department to London, 30 January 1953; Letter State Department to Brussels, 27 March 1953; Box 498, Letter A-150 State Department to Lisbon, 19 March 1954; Letter A-210 State Department to Cairo, 1 April 1954; Letter A-508 State Department to Manila, 4 June 1954; Letter A-10 State Department to Buenos Aires, 12 July 1954.

43. Ibid., RG 59, 1955–59, Box 493, Letter A-147, Dillon to Moscow, 13 February 1959; Letter CA-7064 Herter to Bucharest, 17 February 1959.

44. Ibid., RG 59, 1955–59, Box 493, Letter CA-9543, Herter to Cape Town, 4 May 1959.

45. Weatherford, Bill, ‘The Diplomatic Telecommunications Service’, CANDOER News, 7, no. 3 (2007), February 10, 2023, www.candoer.org/issue73.html

46. Daugherty, The Marine Corps, 101.

47. Aldrich, GCHQ, 195; NARA, RG 59, 1955–59, Box 491, Telegram 1161 Taipei to State Department, 25 May 1957, Telegram 1208 Taipei to State Department 28 May 1957, Memorandum Jones to Robertson 29 June 1957; Library of Congress, Frontline Diplomacy: The Foreign Affairs Oral History Collection, Interview with Thomas S. Estes. 11 May 1988.

48. Between 1947 and 1954 the principal Soviet foreign intelligence service went through several changes of name before it settled on KGB (Committee of State Security). For simplicity’s sake, this article refers to the organisation throughout as the KGB even when that may be anachronistic.

49. McMillin, Stationed in Moscow, 68–71,

50. Ibid., 22–23, 65–66.

51. Ibid., 70; Bagley, Spymaster, 7.

52. Bagley, Spymaster, 7.

53. NSA, History of the Army Security Agency: Post War Transition Period, 1945–48, 7 April 1952.

54. ”Soviet Paper Interviews Turncoat GI,” The Washington Post, 13 December 1956.

55. Bagley, Spymaster, 8–14.

56. Ibid., 1–2, 11–12.

57. Widen, “The Wennerstrom spy case,” 934, 943, 945–946.

58. Senate Judiciary Committee, 88th Congress, Subcommittee to Investigate the Administration of the internal Security Act, The Wennerstroem Spy Case: Excerpts from the Testimony of Stig Wennerstroem, a Noted Soviet Agent, 1964, 151.

59. NARA, The President John F. Kennedy Assassination Records Collection, JFK Assassination Records − 2018, Additional Documents Release, (NARA JFK), CIA Study, The Case of Yuriy Ivanovich Nosenko, Volume III, February 1967, 413–414, 416–417; NARA JFK, CIA Study, The Examination of the Bona Fides of a KGB Defector: Yuri I. Nosenko, February 1968, 33, 35–36. https://www.archives.gov/files/research/jfk/releases/2018/104–10150–10136.pdf (Accessed 10 May 2023).

60. NARA JFK, CIA Study, The Examination of the Bona Fides of a KGB Defector: Yuri I. Nosenko, February 1968, 36.

61. Fursenko and Naftali, Khrushchev’s Cold War, 560.

62. NARA, RG 59, 1950–1954, Box 720, Despatch 175, Moscow to State Department, 22 October 1954.

63. Ibid.

64. State Department, History of the Bureau, 233; NARA, RG 59, 1964–66, Box 8, Letter Dutton to Huddleston, 4 June 1964.

65. NARA JFK, CIA Study, The Case of Yuriy Ivanovich Nosenko, Volume II, February 1967, 252–256, 268.

66. Ibid., Volume III, February 1967, 591.

67. Ibid.

68. Ibid., 592.

69. Emelyanov, Larin and Butyrsky, ‘The transformation of cryptology’.

70. Ibid; ‘FAPSI’ television documentary by Sovershenno Sekretno, broadcast 25 October 1997, November 12 2019, https://www.youtube.com/watch?v=oiGkPK3Kt4k

71. Emelyanov, Larin and Butyrsky, ‘The transformation of cryptology’.

72. Senate, 87th Congress, Supplemental Appropriations for 1963, Hearings before the Committee on Appropriations, 2nd Session on H.R. 13290, 239, 250, 252–3.

73. NARA, RG 59, 1960–1963, Box 208, Memorandum, Hanes to Dwinell, 3 October 1960.

74. Easter, ‘Nikita Khrushchev’, 469.

75. Ibid., 468–469.

76. Ibid., 470.

77. NARA JFK, CIA Study, The Case of Yuriy Ivanovich Nosenko, Volume III, February 1967, 592.

78. Ibid., 590.

79. Gale, U.S. Declassified Documents Online, Minute for President’s Foreign Intelligence Advisory Board, “Secure Room Installations,” January 7, 1966,10 June 2022 https://www.gale.com/intl/c/us-declassified-documents-online/

80. NARA, RG 59, 1960–1963, Box 208, Minute Dillon to Gates, 5 November 1960.

81. Senate, 87th Congress, Supplemental Appropriations for 1963, Hearings before the Committee on Appropriations, 2nd Session on H.R. 13290, 1 October 1962, 229, 239.

82. Ibid., 229, 239, 250–255.

83. Ibid., 229.

84. Ibid., 239.

85. Library of Congress, Frontline Diplomacy, Interview with William J. Crockett, 20 June 1990; John F. Kennedy Presidential Library, Oral History Interview, William H. Orrick, 14 April 1970.

86. May and Zelikow, The Kennedy Tapes, 360.

87. Ibid.

88. Foreign Relations of the United States, 1961–1962, Volume XXV, Organization of Foreign Policy; Information Policy: United Nations; Scientific Matters, Document 436, Memorandum Wiesner to Kennedy, 25 October 1962; NARA, RG 59, 1960–1963, Box 208, Circular Telegram 699, Rusk to embassies, 30 October 1962.

89. Johnson, American Cryptology, 219; Klein, Securing Record Communications, 10–11.

90. CIA Freedom of Information Act Electronic Reading Room (CIA FOIA), https://www.cia.gov/readingroom/home History of the Office of Communications, Chapter III, Section F, The Headquarters Signal Center, not dated.

91. CIA, FOIA, “Diary Notes,” 29 October 1962.

92. Ibid., Letter “Privacy of CIA Intelligence Traffic Transmitted by Electrical Means,” Director of Communications to Director of Central intelligence, 26 October 1962.

93. Ibid.

94. NARA. RG 84, Records of the Foreign Posts of the Department of State, U.S Embassy Jakarta, Classified Central Subject Files, 1963–1969, CR7 Telecommunications Series, 1965, Airgram CA-6180 State Department to all Diplomatic and Consular posts, Enclosure A, 6 December 1962.

95. Lamb, Yvonne, “John W. Coffey, 91: CIA Communications Expert,” Washington Post, 7 August 2008; Library of Congress, Frontline Diplomacy, Interview with William J. Crockett, 20 June 1990.

96. History of the Bureau, 169.

97. Senate, 88th Congress, Staff Reports and Hearings submitted to the Committee on Government Operations by the Sub Committee on National Security and International Operations, 1965, 509; “Lee Parke Resigns: Mr Rusk Cites His Service Record,” Department of State News Letter, No. 35, March 1964.

98. History of the Bureau, 169

99. Senate, 88th Congress, Hearings before the Senate Sub-Committee on Appropriation on HR11134, Departments of State, Justice, and Commerce, the Judiciary and related agencies appropriations, Part 1, 1964, 619–620; John F. Kennedy Presidential Library, National Security Action Memoranda, NSAM 201, Establishment of Sub-Committee on Communications, 17 November 1962–21 May 1963, Final Report of the NSC Sub-Committee on Communications, not dated.

100. NARA, RG 84, State Department, U.S Embassy Jakarta, Classified Central Subject Files, 1963–1969, CR7 Telecommunications Series, 1965, Airgram CA-6829, State Department to selected posts, Enclosure ‘Off Line Crypto Plan’, 6 January 1965.

101. Ibid., Airgram CA-13202, State Department to selected posts, 9 June 1965.

102. Library of Congress, Frontline Diplomacy, Interview with Nuel L. Pazdral, 3 August 1992.

103. Marchetti and Marks, The CIA, 180.

104. Kahn, The Codebreakers, 712.

105. Easter, ‘Protecting Secrets’, 163–164.

106. CIA FOIA, Fragment of internal history of USIB, “Volume IV Increased and Varied Intelligence Needs in Support of President Johnson,” not dated.

107. NARA JFK, CIA Study, The Case of Yuriy Ivanovich Nosenko, Volume III, February 1967, 591–2.

108. Ibid. 592.

109. Ibid.

110. NARA, RG 59, Records of Ambassador at large Llewellyn Thompson, 1961–1970, Lot 67 D2, Box 10, Memorandum by Davies, “Damage Estimate: Foreign Policy Interests,” 28 May 1964; RG 59, Central Foreign Policy Files, 1964–66, Box 2872, Minute Downey to Director of Security, CIA, Attachment, 5 October 1964.

111. NARA, RG 59, Records of Ambassador at large Llewellyn Thompson, 1961–1970, Lot 67 D2, Box 10, Memorandum Johnson to Thompson, 7 June 1964.

112. CIA FOIA, Fragment of internal history of USIB, “Volume IV Increased and Varied Intelligence Needs in Support of President Johnson,” not dated.

113. NARA JFK, CIA Study, The Examination of the Bona Fides of a KGB Defector: Yuri I. Nosenko, February 1968, 239.

114. Ibid.

115. Foreign Relations of the United States, 1955–1957, Soviet Union, Eastern Mediterranean, Volume XXIV, Document 46, 18 May 1956; Document 48, 31 May 1956.

116. Bagley, Spymaster, 11–12.

117. Ibid., 1–2.

118. Ibid.

119. Ibid.

120. International History Declassified podcast, Episode 3, “Stalin, Mao, and an Archival Examination of the Korean War with Sergey Radchenko,” 20 June, 2020 https://www.wilsoncenter.org/audio/international-history-declassified-stalin-mao-and-archival-examination-korean-war-sergey; E-mail, Radchenko to author, 15 July 2023.

121. NSA, Summary Annual Report of the Army Security Agency, Fiscal Year 1948, July 1958, 13–14.