December 4, 2012

Pictures at the NSA's 60th anniversary

Last month, on November 4, 2012, the National Security Agency (NSA) of the United States celebrated it's 60th anniversary. The NSA is one of the world's largest intelligence agencies, responsible for gathering foreign signals intelligence and protecting domestic communications.

For this diamond anniversary, NSA published a full color illustrated publication (available here in PDF) with an interesting overview of its history. In this booklet there are also nice pictures, some of them unseen until now:

President George H.W. Bush using a secure Motorola STU-III telephone.
Such a phone was placed everywhere where the president stayed during a travel,
so he was able to always place secure calls. This purpose is also indicated
by the plate below the phone. It's not clear what the white device is for.
This black Motorola STU-III still served in this function, when president George W. Bush
was calling during his stay at the elementary school on September 11, 2001.
(Photo: NSA - Click for a bigger version)

The new National Security Operations Center (NSOC) at the NSA
This center was established in 1968 as the National SIGINT Watch Center (NSWC)
and renamed into National SIGINT Operations Center (NSOC) in 1973.
This "nerve center of the NSA" got its current name in 1996.
(Photo: NSA - Click for a bigger version)

The NSA/CSS Threat Operations Center (NTOC) at the NSA
From left to right we see a black STE secure phone, an unidentified,
but quite common black phone, and a white Nortel M3904 phone,
which is connected to the NSA Secure Telephone System (NSTS).
(Photo: NSA - Click for a bigger version)

Many more new pictures and also newly declassified documents can be found via the timeline at the 60th anniversary-page on the NSA-website!

Earlier this year, NSA also cooperated with the National Geographic Channel in making what is said to be the first documentary about this agency since the 9/11 attacks in 2001:

With a close look at this video, we can recognize a number of different telephone systems used at the NSA. Some of them we already mentioned here earlier, more of them we will discuss sometimes later on at this weblog.

Update January 12, 2014:

After the Snowden-scandal, a new television report with some unique insights into the NSA was broadcasted in the CBS 60 Minutes show on December 15, 2013.

November 26, 2012

Bilateral Hotlines Worldwide

(Updated: September 2, 2023)

In a previous article we discussed the Washington-Moscow Hotline, being the most famous bilateral hotline. It was soon followed by direct communication links between a number of other countries with nuclear capabilities.

In general these hotlines started as a teletype connection, being upgraded with facsimile units in the eighties and were eventually turned into dedicated secure computer networks. An exception is the hotline between Washington and London, which was a phone line already since 1943.

Overview of the top level bilateral hotlines worldwide
(Click to enlarge)

The hotlines between the heads of governments, are meant to prevent (nuclear) war in times of severe crisis. For preventing misunderstandings and miscommunications in less critical situations, countries have also set up lower level telephone hotlines between their defense or foreign ministers. For example, the United States has so called Defense Telephone Links with at least 23 other states.

Overview of the lower level bilateral hotlines worldwide
reflecting political and military relationships between countries
(Click to enlarge)


- In 1963 the United States and the Soviet Union established the Direct Communications Link (DCL) or Washington-Moscow Hotline. This highly secured connection originally used teletype machines, which were replaced by facsimile units in 1988 and is using e-mail since 2008.

- In 1990 both countries agreed to establish a direct, secure telephone link between Washington and Moscow, which is officially called the Direct Voice Link (DVL) and is maintained by the White House Communications Agency.

- In 2008, Russia and the United States agreed to set up a Direct Secure Communications System, which is an encrypted computer network for both the original Hotline and the Direct Voice Link. Since 2013 this network is also used for a voice link to manage cybersecurity incidents and in December 2021, for a secure video call between the Russian and the American presidents.

The Washington-Moscow Hotline terminal room at the Pentagon in 2013

Between the United States and Russia there are also the following lower level communication links:

- In 1988 the Nuclear Risk Reduction Center (NRRC) was established at the US Department of State, which is used to exchange information in support of arms control treaties. After the split-up of the Soviet Union this secure data exchange connection, called Government-to-Government Communication Link (GGCL), was extended to Ukraine, Belarus, and Kazakhstan. Since 2013, the NRRC also maintains a communications link with Russia for the exchange of information about cybersecurity risks.

- In 2000 the US and Russia signed an agreement for the establishement of a Joint Data Exchange Center (JDEC) to share early warning information on missile and space launches to reduce the risk that a test launch could be misread as a missile attack. It's not clear whether this center has already been realized or not.

- In 2013, a direct secure voice line was set up between the US Cybersecurity Coordinator and the deputy secretary of the Russian Security Council in order to manage crisis situations arising from cybersecurity incidents.

- In 2015, the American and the Russian military created a back-channel after Russia entered Syria's multi-sided civil war. This de-confliction line consisted of a non-secure telephone line and a Google e-mail account, which proved useful in avoiding serious accidents.

- On March 1, 2022, a military de-confliction 'hotline' was established in order to prevent an accidental clash between Russia and the US during the Russian invasion of Ukraine. This link is basically an exchange of phone numbers between both sides for quick access. The US side will be run out of the US European Command's operations center in Stuttgart, Germany, while the Russian side is expected to be coordinated out of the Ministry of Defense in Moscow.

Besides these bilateral hotlines with Russia, the United States also has the following lower level communication links with other nations:

- There is a secure telephone line called Foreign Affairs Link (FAL) between the US Department of State and Russia (since 1999), Japan, Mexico, Germany and Israel.

- There is or was a Defense Telephone Link (DTL) between the US Department of Defense and Russia (since 1994), China (since 2008), Albania, Oman, Qatar, Latvia, Lithuania, Slovenia, Saudi Arabia, Ukraine, Bulgaria, Kuwait, Estonia, Slovakia, Kazakhstan, Macedonia, Bahrain, Israel (since 1996), United Arab Emirates, Poland, Romania, Czech Republic and Austria.

In March 2022, US defense secretary Llyod Austin and Joint Chiefs of Staff chairman Mark A. Milley tried to set up phone calls, most likely through the Defense Telephone Link (DTL), with their Russian counterparts, but the Russians declined to answer the calls.

- In September 2011, the United States proposed opening a direct military hotline with Iran to avoid a possible conflict erupting over the Iranian nuclear program. Tehran declined the offer.


- Already before Russian armed forces invade Ukraine on February 24, 2022, the United States provided Ukrainian president Volodymyr Zelensky with a secure satellite phone that can put him into an encrypted call with US president Biden. On March 5, 2022, Zelensky used it for a 35-minute call with his American counterpart on what more the US could do to support Ukraine without entering into direct combat with Russian forces. A similar satellite phone was provided to Ukrainian foreign minister Dmytro Kuleba.


- During World War II, two decades before the hotline between Washington and Moscow was established, there was a direct secure telephone link between the Cabinet War Room bunker under Downing Street and the Pentagon with an extension to the White House. From 1943-1946 this link was secured by using the very first voice encryption machine, called SIGSALY.
In the 1950s and 1960s the Washington-London hotline was secured by the KY-9, probably succeeded by the KY-3 voice encryption devices. In the 1980s, the STU-I system was used, to be replaced by a small version of the IST red phone.

British prime minister Margaret Thatcher in her office at Nr. 10 Downing Street in 1987
At the far right we see the beige STU-I telephone for the hotline with the US
(photo: Tim Graham/Getty Images - click to enlarge)


- In 1962, a hotline was established between the White House and the German chancellor's office. Initially, this was non-secure, standard telephone line. In 1969 it was probably replaced by a secure teletype link and since the late 1970s it consisted of secure STU-I telephone sets. Somewhere in the 1990s these were replaced by a small version of the IST red phone.


- The Spanish prime minister José Maria Aznar (1996-2004) was so often in contact with US president George W. Bush, that a special phone line was installed in his office in the Moncloa palace, exclusively for phone calls to the White House. One of those phone calls was just before the war in Iraq and both leaders also talked about developments in South America.*


- In October 1997, US president Clinton and Chinese president Jiang Zemin agreed to "connect a presidential hotline to make it easier to confer at a moment's notice." On April 29, 1998 the United States and China signed an agreement to set up such a direct telephone link between both heads of state. However, this hotline was not used when in 2001 an American EP-3E electronic surveillance aircraft was forced to land on Hainan Island.

- In the Summer of 2021, the Biden administration examined the possibility of setting up an emergency hotline with the office of China's president Xi Jinping in order to avoid accidental escalation at a time of heightening bilateral tensions. However, it's believed that China views hotlines as tools to manipulate rather than to solve crises by de-escalating and communicating between forces like the US does.

- On February 29, 2008, China and the United States agreed to set up a Defense Telephone Link (DTL) between the US Department of Defense and China’s Ministry of National Defense, which became operational in April 2008. Until 2011 this hotline was used only four times, but later it was used somewhat more often and in 2014, the US proposed to upgrade the DTL to video teleconference. In 2020, the DTL was used on a regular basis by various defense officials.


- During a visit of US president Obama to India in January 2015, it was decided to set up a secure hotline between the White House and the Indian prime minister. The link became operational in August 2015 and was said to be established with the help of the US military.


- A hotline connection between Moscow and Bejing was used during the 1969 frontier confrontation between the two countries. The Chinese however refused the Russian peace attempts, and informed Moscow that the direct communications link "was no longer "advantageous" and normal diplomatic channels would suffice". After a reconciliation between the former enemies, the hotline between China and Russia was revived in 1996.* It's not clear whether this hotline is for record or voice communications.
- A telephone hotline between the defence ministries of Russia and China became operational on March 14, 2008.


- Apparently there was a facsimile-hotline between Moscow and Pyongyang, which was used in 1968, when North Korea captured the American spy ship USS Pueblo.*


- Since 1966 there was a direct teletype connection between the French president and the Kremlin. In 1989 the teletype equipment was replaced by high speed facsimile units.*


- Since 1967 there was a direct teletype connection between the British prime minister and the Kremlin. In 1990 it was proposed to install a telephone line between London and Moscow, but British government officials considered it too costly to secure this line through encryption. It seems that this hotline was eventually upgraded with encryption in 2011.


- In 1989 a facsimile connection was established between the West-German capital Bonn and Moscow.* In 1990 there was also a non-secure telephone line between both capitals.
- The Soviet Union also had a hotline with Erich Honecker as leader of the former East-German Republic (DDR). During a short period before East and West Germany were united in 1991, there was a telephone hotline between Honecker and the West-German Bundeskanzler Helmut Kohl.*


- In 2009 Israeli prime minister Ehud Olmert and Egyptian president Hosni Mubarak agreed to pass on relevant intelligence information immediately using a hotline, primarily to combat smuggling from Sinai into the Gaza Strip.


- In 2015, Russian armed forces in Syria had set up a hotline with the Israeli military to avoid accidental clashes in the Syrian sky: "Mutual information-sharing on the actions of aircraft has been established through a hotline between the Russian aviation command center at the Hmeimim air base and a command post of the Israeli Air Force."


- After the 1971 war between India and Pakistan, a secure communications link between the Prime Minister Secretariat in Islamabad and the Secretariat Building in New Delhi was established, but it was seldom used until the 1990s.
- In 2004, both countries agreed to set up an additional secure hotline between their foreign ministers, aimed at preventing nuclear risks.
- In 2011, India and Pakistan agreed to set up a 24/7 non-encrypted hotline between their interior ministers, that will facilitate real-time information sharing on terrorist threats.


- Since 2005 there's a non-encrypted hotline between the foreign ministers of India and China for building "mutual political trust".
- In 2009 both countries agreed to set up a direct, secure telephone link between the Chinese premier and Indian prime minister, which was meant as a confidence building measure and to maintain regular contacts at the highest level. The agreement for this hotline was signed in April 2010.


- There's also a non-encrypted hotline between Delhi and Moscow, which was established before 2009.


- A first telephone hotline between North and South Korea became operational on September 22, 1971. Many low-level phone lines between both countries followed, until there were 33 lines through Pamnumjom and 15 lines outside that border town. A top-level telephone hotline between the presidents of North and South Korea was established on April 20, 2018, in preparation of a summit between both leaders.

A South Korean liaison officer speaks with his North Korean counterpart over the
inter-Korean communications channel at Panmunjom, January 3, 2018
(photo: Unification Ministry - click to enlarge)


- In September 2012, China and South Korea agreed to set up a consular hotline between their defense ministries to protect rights of their citizens who are staying in the other country. In April 2013 both countries agreed to set up a second, 24-hour hotline to deal with the rising tension over North Korea.


- In June 2013, China and Vietnam agreed to set up a naval hotline between their defense departments, in order to keep a peaceful and secure maritime environment in the South China Sea, amid escalating maritime tensions over disputed South China Sea islands.

In 2010, China and Japan agreed to establish a hotline between their political leaders, following a series of naval incidents, but the plan wasn't realized. Defence officials of the two countries also agreed in 2011 to set up a military-to-military hotline by the end of 2012, but the talks stalled due to heightened tensions over the territorial row. In February 2013, Japan again suggested to establish a China-Japan hotline, and reiterated this once again in January 2014.

In September 2016, China and the Southeast Asian countries decided to set up hotlines and adopt communications protocols to avoid potential naval clashes in the disputed waters of the South China Sea.

When more information about these hotlines becomes available, it will be added here. Some of the most notable bilateral hotlines will be discussed later on this weblog.

Links and Sources
- The Rand Blog: Another 'Hotline' with China Isn't the Answer, July 2022
- Politico: Pentagon wants Moscow back channels to prevent nuclear escalation, February 2022
- National Communications System, Forty Years of Service to the Nation: 1963-2003, 2003
- Haraldur Þór Egilsson, The Origins, Use and Development of Hot Line Diplomacy, Institute Clingendael, 2003
- US Department of State, Bureau of Information Resource Management (IRM), 2011

November 16, 2012

Commander Petraeus' phones

Last week, David Petraeus resigned as director of the Central Intelligence Agency (CIA), after admitting he had an extramarital affair with his biographer Paula Broadwell. This led to many news reports and also many pictures on the internet.

Some of them give a nice look at the telecommunications equipment which general Petraeus used when, from July 2010 to July 2011, he was commander of the International Security Assistance Force (ISAF) in Kabul, Afghanistan:

ISAF Commander Petraeus being interviewed by Paula Broadwell
(Photo:, date unknown)

In this picture we see the following telecommunication devices:

Video conferencing screens
On Petraeus' desk we see two Centric 1700 MXP video teleconferencing screens, made by the Norwegian manufacturer Tandberg. In 2010 this company was bought by Cisco Systems, and so the 1700 MXP screens are often used by US military officials. They are equipped with a HD camera and have a widescreen LCD screen, which operates both as a video conferencing system and PC display.

Left of the personal computer screen we see a Secure Terminal Equipment (STE), made by L3 Communications. The STE is a phone capable of encrypting calls up to the level of Top Secret/SCI. This phone can be used to have a secure line to anyone with a similar device.

Right behind the chair of commander Petraeus is an Integrated Services Telephone 2 (IST-2), made by Telecore Inc. This is a so called "red phone", which is part of the Defense Red Switch Network (DRSN), connecting all mayor US command centers and many other military facilities. This is the primary telephone network for military command and control communications.

VoIP phones
In the picture above we see three of four Voice over IP (VoIP) phones: at the right end a Cisco SPA and the other three being phones from the Cisco 7970-series. It's likely each of these phones is part of a separate telephone network. Nowadays many military phone networks use Voice over IP, often with Cisco IP phone sets. These phones have no encryption capability, but their voice data networks can easily be secured with specific network encryptors.
In the picture below we can see al four VoIP phones, neatly aligned on a shelf and with an organizational chart at the left side of them:

General David Petraeus in his office at the ISAF headquarters in Kabul.
(Photo: Adam Ferguson/The New York Times, March 8, 2011)

Also in this picture we see three printers on a table at the left side of the room. Apparently there are separate printers for different computer networks, in order to keep documents of different classification levels separated.
At the upper left corner of the front of at least the first two printers we can see the colored classification labels: a green label for Unclassified materials on the printer in the foreground and a red label for materials classified as Secret on the printer in the middle. The third printer seems to have no marking, but we can assume this one is for Top Secret (orange label) or Classified SCI (yellow label) documents.

This kind of communications equipment is typical for US military commanders in similar positions. Therefore one can quite easily recognize it also on other pictures of American military commanders and command centers. Contrarily, pictures in which we can see the equipment used in Petraeus' last office, that of director of the CIA, are very rare - but we keep looking!

UPDATE February 5, 2013:

A reader of this weblog kindly noticed me of another picture of general Petraeus in his office, with clearly visible another kind of communications device. It's an HH2G Tetrapol handheld radio device, sitting in a desktop adapter, so it can be more or less used like a phone:

General David Petraeus in his office in ISAF headquarters in Kabul, Afghanistan
(Photo: Chris Hondros/Getty Images Europe, October 21, 2010)

The Tetrapol secure voice and data radio network was installed in 2004 by Cogent Defence and Security Networks, the UK operating company of EADS Defence and Communications Systems Group. This trunked Tetrapol ISAF Command Network, with end-to-end security, provides command communications coverage for the NATO Area of Responsibility in the Kabul region.

October 28, 2012

The Washington-Moscow Hotline

(Updated: September 2, 2023)

In October 1962, the Cuban Missile Crisis ended and the world was saved from falling into a nuclear war. In order to prevent this risk in the future, the United States and the Sovjet Union established a direct communication line between their two capitals in August 1963. This Washington-Moscow Hotline became one of the most famous top level communications systems in modern history.

In popular culture, the Washington-Moscow Hotline is often called the Red Phone, and therefore many people think it's a telephone line, with a red phone set on the president's desk. However, this is false: the Hotline was never a phone line, but instead set up as a teletype connection, which in 1988 was replaced by facsimile units. Since 2008 the Hotline is a highly secure computer link over which messages are exchanged by e-mail.

Washington-Moscow Direct Communications Link or Hotline


Given the growing threat of a nuclear war, leaders in Washington and Moscow realized already in 1954 that a direct line of communications between their two nations was needed to prevent such a disaster. The Soviets floated the idea publicly for the first time that year, and in 1958 the United States proposed that both nations take part in the Conference of Experts on Surprise Attack in Geneva, Switzerland.

Also in 1958 the political economist and nuclear strategist prof. Thomas Schelling proposed the idea of a hotline between both super powers. A direct phone line also featured in the novel Red Alert by Peter Bryant from the same year. Based upon this novel was Stanley Kubrick's 1964 film Dr. Strangelove, both showing how a nuclear war breaks out because of bad communications.

What shaped people's imagination:
the American president (right), assisted by the Russian ambassador,
calling his Soviet counterpart in the 1964 film Dr. Strangelove

In 1960, Jess Gorkin, editor of the magazine Parade, published an open letter in his magazine to President Dwight D. Eisenhower and the Soviet leader Nikita Khrushchev, concluding with: Must a world be lost for want of a telephone call? However, the military and diplomats of the State Department didn't like the idea of the president talking behind their backs with the Russians and reportedly objected the proposal of a direct line.

During the Cuban Missile Crisis in October 1962 it clearly came out that the existing ways of communicating between Washington and Moscow were too slow for the events happening. It took Washington nearly 12 hours to receive and decode Khrushchev's 3,000 word initial settlement message.

By the time a reply had been written and edited by the White House, Moscow had sent another, tougher message. Under severe time pressure, both leaders ultimately decided to communicate through the media. After the crisis was resolved, the hot line proposal became an immediate priority.

After some negotiations, the United States and the Sovjet Union signed an agreement about establising a Direct Communications Link on June 20, 1963 in Geneva. The official American name for the Hotline is Direct Communications Link (DCL), but US technicians often call it MOLINK, being a military style abbreviation for "Moscow-link".


On July 13, 1963, only a month after signing the agreement, the United States sent four sets of teleprinters with Latin alphabet to Moscow for their terminal. This was done via US ambassador Averell Harriman's plane. Another month later, on August 20, the Soviet equipment, four sets of teleprinters with Cyrillic alphabet, arrived in Washington. The cipher machines for encrypting the Hot Line messages came from Norway. According to the agreement, all these machines should be accompanied by a one years supply of spare parts and all the necessary special tools, test equipment, operating instructions and other technical literature.

Russian technicians preparing the equipment for the new Hotline
in the Central Telegraph Bureau in Moscow.
In the foreground we see the East German T-63 cyrillic teleprinter.
(photo: TASS via AP, July 17, 1963)

News report of the Russian teleprinters being installed at the Pentagon

Two unique color film fragments of the Russian teleprinters arriving and being installed at the Pentagon can be seen here: Part 1 - Part 2

The new Hotline became operational on August 30, 1963, by transmitting the first test messages. Washington sent Moscow the text The quick brown fox jumped over the lazy dog's back 1234567890, which is a so called pangram of all letters and numbers of the Latin alphabet. The Soviets sent back a poetic description of Moscow's setting sun.

When the Hotline was established in 1963, it was a full-duplex teletype channel, which was routed trough telephone cables from Washington, over the undersea Transatlantic Cable No. 1, to London, and from there to Copenhagen, over Stockholm and Helsinki to Moscow. In London, the Washington-Moscow Hotline cables were connected by a secure telephone exchange, situated in a huge underground tunnel complex, The Kingsway Tunnels, built during World War II.

This cable connection was for the political communications, but appeared not fully fail safe: the cable was accidently cut several times, for example near Copenhagen by a Danish bulldozer operator and by a Finnish farmer who plowed it up once.

Besides this wire line link, there was a full duplex teletype radio circuit, routed from Washington via Tangier (Morocco) to Moscow. This was for service communications and served as a back-up.

The Hotline terminals

In Moscow, the terminal of the Hotline was supposed to be in the Kremlin, somewhere next to the office of the prime minister. However, Soviet leader Leonid Brezhnev once told a group of Moscow-based American journalists, that their terminal was on the opposite side of Red Square, in the Communist Party headquarters. The Russian terminal was manned by civilians, the American one by the military.

An East German T-63 teleprinter, used at the Moscow terminal of the Hotline
(photo from an exhibition at the Russian Archives)

On the American side, there are Hotline terminals at these four locations:

- The National Military Command Center (NMCC) in the Pentagon
- The Alternate National Military Command Center (ANMCC) in the Raven Rock Mountain
- The military communications center in the White House
- An unknown location in the State Department

Pentagon Terminal

The primary US terminal is at the National Military Command Center (NMCC) in the basement of the Pentagon. There, the Direct Communications Link is a joint staff operation under the control of the Joint Chiefs of Staff J-3 Operations Directorate. The NMCC is responsible for routine testing of the Hotline and for the receipt, transmission and translation of the messages by highly qualified translators.

The terminal is manned by six teams of two man each, working in 8-hour shifts and led by a commissioned officer acting as Presidential Translator (PT). For the routine shift operations, the Hotline personnel falls under the command of the flag officer in charge of the NMCC. But when a real message from Moscow arrives, the doors of the terminal room are closed and locked and the personnel becomes subject directly to the president himself.

The rack with the Primary Tech Control (PTC) equipment at the NMCC
(photo: private collection - click to enlarge)

White House Terminal

When in June 1967 the Soviets sent their first message, secretary of defense Robert McNamara found out that the Hotline ended in the NMCC, instead of at the White House, as he had expected. McNamara ordered a quick patch from the Pentagon to the White House, which was later formalized by installing an ancillary terminal in the military communications center of the White House Communications Agency (WHCA) in the East Wing basement. From there, incoming messages from the Hot Line were sent to the Situation Room under the West Wing, first by pneumatic tube and later, after computers were installed in both rooms, by data transmission.

The White House terminal also has the capability to send and receive messages and has additional privacy and override features which will allow it to "lock out" other Hotline terminals. The White House terminal is manned and operated by White House personnel of the WHCA. In 1988, the White House communications center was connected to the Pentagon MOLINK office with a facsimile link, two secure telephone lines and an open, non-secure telephone line.*

The rack with the T2 equipment at the White House
(photo: private collection - click to enlarge)

Other US Terminals

Another Hotline terminal is located at the Alternate National Military Command Center (ANMCC), which is situated in the Raven Rock Mountain and serves as a back up facility for the Pentagon. This terminal has the capability to serve as an alternate center for originating and receiving messages. The ANMCC terminal is manned and operated by NMCC personnel, which is also responsible for the periodic testing of this terminal. According to a 2013 report, the Hotline also has a link to the State Department.

In a paragraph classified as Secret of the 1985 presidential directive about the operation of the Hot Line, which in the meanwhile has been declassified, it was said that at the sole discretion of the president, additional locations for access to the Hotline may be established. The existence of these sites should be classified as Secret.

The rack with the Alternate Tech Control (ATC) equipment at the ANMCC
(photo: private collection - click to enlarge)

Record communications

Contrary to the myth of a phone line, the Washington-Moscow Hotline has always been for record communications. The idea behind this is that a telephone link could increase the possibility of misunderstanding rather than eradicate it. In times of crisis, mistakes come at a high price. Exchanging written messages gives both parties time for reflection and responding after deliberation. The telephone does not allow this latitude, but on the contrary compels a response of some sort, which can result in a misguided reply or a misunderstood answer.

Another reason for the Hotline not being for phone conversations was of technical nature: in the sixties it was hardly possible to realize voice encryption strong enough for top level communications. From the mid-seventies some better techniques were developed, but these were secret national algorithms, which of course couldn't be shared with the Soviets. Unclassified commercially available voice encryption was hardly secure.

The interior of an East German T-63 SU12 teletype printer
as photographed in the National Cryptologic Museum of the NSA.
At the left we see a green box containing the key tape.
(Photo: Wikipedia - click for a bigger version)

1963: Teletype equipment

The original teletype equipment of the Washington-Moscow Hotline consisted of the following machines:

- Teleprinters with Latin alphabet: Model 28 ASR, made by the Teletype Corp.

- Teleprinters with Cyrillic alphabet: T-63 SU12, made by VEB Messgerätewerk Zwönitz in East Germany, based on the earlier Siemens T-37 teleprinter.

For the encryption of the messages, each of these teleprinters was connected to an ETCRRM II machine, which will be discussed later on. We can clearly see the equipment in this picture of the Hotline terminal room at the Pentagon:

The Washington-Moscow Hotline terminal room in the NMCC at the Pentagon, 1966.
At the left side, there's the Teletype Corp. Model 28 ASR teleprinter in the foreground,
two black ETCRRM II encryption machines in the middle, and top left a T-63 SU12 teleprinter.
This arrangement is mirrored at the right side of the room.
(Photo: June 1966)

As we can see by comparing the previous picture with the next one, the Hotline equipment in the Pentagon was rearranged, and maybe also replaced to another room, after 1966. Maybe this happened in 1967, when defense secretary McNamara ordered that the Hotline should be extended to the White House.

The Hotline terminal room in the NMCC at the Pentagon, 1976
With two Latin alphabet and two cyrillic alphabet teletype machines (light coloured)
and four ETCRRM II cipher machines (black).
(Photo: UPI, July 9, 1976)

In 1980, the equipment was replaced by newer teletype printers and Siemens M-190 encryption machines, as can be seen in the picture of the Hotline room from 1985:

The Hotline terminal room in the NMCC at the Pentagon, 1985
With the new teletype and encryption equipment, installed in 1980.
In the foreground we see a Siemens M-190 cipher machine.
(Photo: AP, August 27, 1985)

Shortly after the previous picture was taken, facsimile units and personal computers with printers were added to the Washington-Moscow Hotline. For a couple of years they were tested and used alongside the existing teletype equipment, as can be seen in the picture:

The Washington-Moscow Hotline terminal room in the NMCC at the Pentagon, 1985
We see four personal computer terminals with printers for the coordination channel
Just like the teleprinters, two of the computers had a Cyrillic keybord and two a Latin keybord
In the foreground we still see a teleprinter and a Siemens M-190 cipher machine
(Photo: Time-Life/Scott Davis, November 14, 1985)

Teletype encryption

From the beginning, the confidentiality of the messages through the Washington-Moscow Hotline was assured by encrypting them using the one-time tape method, which has been proved unbreakable if used correctly.

The encryption of the teletype transmissions was realised by an Electronic Teleprinter Cryptographic Regenerative Repeater Mixer II, short ETCRRM II. As one of many one-time tape machines sold by commercial firms in those days, this one was produced by the Standard Telefon og Kabelfabrik (STK) in Oslo, a Norwegian subsidiary of the American telecommunications company ITT. It was also commercially available for about 1000,- USD, so for securing the Hotline, neither party had to disclose any of their own secret cryptographic methods.

The ETCRRM II used the Vernam stream cipher method, in which plain text message is eXclusively OR'ed (XOR'ed) with a random stream of data of the same length to generate the ciphertext. Once a message was enciphered the keytapes were destroyed. At the receive end, the process was reversed to decode the meassage, for which an identical keystream tape was needed.

In 1980 the ETCRRM II was replaced by the German Siemens M-190 cipher machine, which also uses the Vernam principle for one-time tape encryption. This device stayed in use until the teletype connection was terminated in 1988.

According to the agreements, each country prepared the keying tapes used to encode its messages and delivered them, through a courier, at their embassy in the other country, from where they were brought to the counterpart's terminal. So, the keys used for encrypting the messages sent from Washington, were brought to the American embassy in Moscow, who delivered them to the Russian hotline terminal.

In the US, the key tapes were provided by the Office of Communications Security (now: Information Assurance Directorate) of the NSA. Just imagine the logistics needed for providing not only the Pentagon and the White House terminals, but also the American embassy in Moscow with these key tapes every single day!

A Siemens M-190 encryption machine

1978: Satellite link

On September 30, 1971, the United States and the Soviet Union signed an agreement in Washington to modernize the Hotline. The primary cable link was replaced by two satellite circuits: the United States was to provide one circuit via the commercial Intelsat IV system, with satellites in a geosynchronous orbit. The Soviet Union would provide another circuit via four satellites of their Molniya II system on a highly elliptical orbit.

This modernization program started in 1971 and, after four years of testing, the satellite link finally became operational on January 16, 1978. This link provided more flexible communications and made the Hot Line less vulnerable than the original landline. The teletype circuit over the undersea and land line cable was retained as a backup to the satellite links, but the teletype radio circuit from Washington over Tangier to Moscow was terminated.

Maybe it's because the 1971 agreement says: "The two circuits shall be duplex telephone band-width circuits (...), equipped for secondary telegraphic multiplexing", that some sources erroneously say that in the seventies a telephone capability was added to the Hot Line.

Sign at the US hotline satellite earth station at Fort Detrick
(photo by Tim Tyler)

Earth stations

Both in the United States and in the Soviet Union satellite earth stations were equipped for the Hotline transmissions. For the signal of the Russian Molniya satellite, a new earth station was built at Fort Detrick, Maryland. For the Intelsat link, the US used the commercial Intelsat ground station at Etam, West Virginia. Commercial circuits connect these earth stations to the Hotline terminal at the National Military Command Center in the Pentagon.

The Soviets originally intended to use an earth station in the suburbs of Moscow for the Intelsat link and a Molniya station at Vladimir. However, because of severe winter weather conditions in the Soviet Union, the Russians constructed a second Intelsat earth station, approximately 50 miles from L'vov, to ensure increased dependability.* Since 1991 L'vov is in Ukraine, so it's likely the Russians moved their Intelsat earth station to another location.

The rack with the Earth Station 2 (ES2) equipment at
the Intelsat ground station in West Virginia
(photo: private collection - click to enlarge)

Detrick Earth Station

The US ground station at Fort Detrick was built by the Radiation Division of the Harris Corporation, and became operational in the Spring of 1974. Harris operated and maintained the station and its equipment through 1977. Since 1981 Honeywell Technology Solutions Inc (HTSI) provides 24/7 Russian linguist support and technical support for the operation of the Detrick Earth Station (DES), ensuring that the availability is maintained at greater than 99.97 percent. A renewed five-year $8.4 million contract with Honeywell ends in February.

The US earth station at Fort Detrick, Maryland
with the 1974 dishes for the Russian satellites.

The rack with the Earth Station 1 (ES1) equipment at Fort Detrick
(photo: private collection - click to enlarge)

The Detrick earth station was modernized by the Satellite Communications Systems of the US Army in 2007. Outdated equipment was replaced by state-of-the-art systems and new 15-meter satellite dishes were installed. Now the station has a multi-carrier, multi-satellite capability, instead of the previous point-to-point, single-satellite, single-carrier system.

The twin satellite dishes are being kept operational by a staff of 16 civilian Army employees: eight technicians and eight linguists. They work around the clock to ensure the system is operating correctly. The station supports not only the Hotline, but also a number of other critical Government-to-Government Communications Links (GGCL) between the United States and Russia.

The modernized US earth station at Fort Detrick
with the 2007 dishes for the Russian satellite link

1988: Facsimile equipment

In May 1983, president Reagan proposed to upgrade the Hotline by the addition of high-speed facsimile (fax) capability. This was followed by bilateral negotiations, leading to an agreement signed by the United Stated and the Soviet Union on July 17, 1984. This agreement was subsequently updated by an exchange of diplomatic notes in Washington, on June 24, 1988.

According to the agreement, at each end of the Hotline facsimile terminals of the same make and model were installed. It was specified that (digital) Group III facsimile units had to be used, operating at 4800 bits per second. Faxes like this take between 6 and 15 seconds to transmit a single page, which was much faster than the 66 words per minute capability of the existing teletype connection.

All facsimile equipment was provided by the United States, as well as the IBM personal computers used for the secure orderwire channel to allow coordination between the distant ends. These computer had standard USSR Cyrillic and United States Latin keyboards and "cathode ray tube displays to permit telegraphic exchange of information between operators". Printers had to provide record copies of all information exchanged on the orderwire channel.

The installation of the new facsimile and computer equipment was completed in the summer of 1985. It was tested and used alongside the existing teletype connection for several years, and after it had proved to be reliable enough, the teletype circuits were turned off in 1988.

The Hotline terminal room in the NMCC at the Pentagon, 1985
Two of the IBM personal computers, each with an Epson FX-80 dot matrix printer next to it
The units on top of the computer desks are Panafax PX-100 facsimile machines
(photo: Time-Life/Scott Davis, November 14, 1985)

The facsimile machines used for the Hotline were from the type Panafax PX-100 made by Matsushita Graphic Communications Systems, Inc. (better known as Panasonic) and sold in the US through its subsidiary Panafax Corp. from Woodbury, New York. The Panafax PX-100 digital facsimile transceiver was introduced in 1983 and was able to transmit documents with a speed of 40 seconds per page.*

Now, not only plain texts could be sent, but also maps, charts and photographs. The fax units also made it possible to send handwritten messages, like the 13-page handwritten letter which Soviet leader Gorbachev sent to president Reagan using the Hotline in 1986.*

The Panafax PX-100, from an 1983 advertisement

As part of the facsimile upgrade, the Soviets transferred the Hotline transmissions over to a newer, geosynchronous satellite of the Gorizont-class, which was part of their Statsionar system. This eliminated the US ground station at Fort Detrick from having to hand off the transmissions every four hours between the four Molniya satellites.* In 1996, a new Molniya-3 satellite took over the Russian satellite link for the Hotline.

The set-up of the facsimile and computer equipment at the Russian side of the Hotline can be seen in a graphic that was posted on Twitter by the Russian Ministry of Foreign Affairs on August 30, 2021:

The Hotline equipment in Moscow (top left) and the National Military Command Center
in Washington (bottom right) in a graphic from the Russian Ministry
of Foreign Affairs, August 30, 2021 (click to enlarge)

Facsimile encryption

Based upon the 1984 agreement, it seems that the digital data from both the facsimile units and the personal computers were digitally encrypted using the Vernam stream cipher, the same method as was previously used for the teletype transmissions.

This encryption was done by "information security devices", which consisted of microprocessors located in computers with floppy disk drives. These combined the digital facsimile output with buffered random data, which was read from standard 5.25 inch floppy disks. It's not clear whether this encryption was done by the IBM computers of the coordination channel, or by separate ones.

The agreement said that the United States had to provide a specification describing the key data format and necessary keying material on a floppy disk for both parties, until the Soviets had developed this capability as well. Also, the necessary security devices, as well as spare parts for the equipment had to be provided by the American side, in return for payment of costs thereof by the Soviets.

2008: E-mail communications

It's not clear for how long the presidential Hotline kept using facsimile machines. For example, the communication links of the Nuclear Risk Reduction Centers (NRRC) were modernized in 1995, by replacing the facsimile capability with a scanned files transfer (an impression of how this NRRC communication link works will be given later).

In 2007 the Direct Communications Link got a fifth upgrade. As we saw earlier, the US earth station at Fort Detrick was modernized and also the link itself was upgraded to a dedicated computer network linking the Washington and Moscow terminals. This network runs over redundant circuits of two existing satellite links and a new fiber-optic cable, which replaced the old back-up cable link.

This computer link uses commercial software for both chat and e-mail. The chat function is used by the operators for coordination of link operations, while e-mail is used for sending the actual messages. Transmission time is literally near instantaneous. These capabilities became operational on January 1, 2008.*

The Washington-Moscow Hotline terminal room at the Pentagon, 2013
Presidential communicator Navy Chief Petty Officer John E. Kelley (seated) and
senior presidential translator Lt. Col. Charles Cox man the hotline terminal


In August 2018, several Russian state media came with the story that since the existence of the Hotline, a unit of the state-owned defense conglomerate Rostec that specializes in encryption and secure communications, Avtomatika, supplied the White House with the communication technology: "U.S. experts tested and recommended to equip the Moscow-Washington direct line with the system" an unnamed Rostec representative told the RIA Novosti news agency.

A tweet by the Russian Embassy in Washington was a bit more specific, suggesting that this may only apply to the Direct Voice Link (DVL) between the two countries: "A sophisticated scrambler developed by Avtomatica Concern, part of Rostec, was tested by US specialists and recommended for use in the direct telephone link connecting Washington with Moscow"

Operation of the Hotline

The Washington-Moscow Hotline system is used for three types of messages:

- Test Messages: consisting of apolitical, non-propagandistic texts, usually poems, short stories or other writings dealing with nature, classical music, art or literature. These are transmitted daily: every even hour from Washington and every odd hour from Moscow.

- Service Messages: coordinating the operation of the Hotline, about software and hardware issues and also containing a summary of the daily use of the system. These are probably formatted by so called Standard Operating Procedures (SOPs).

- Governmental Messages: the messages send on behalf of the presidents of Russia and the United States.

From Washington all messages are sent in English, using the Latin alphabet, from Moscow in Russian, using the cyrillic alphabet. Translation is done by the receiving party in order to preserve the nuance of each language.

Air Force Sgt. John Bretoski (left) and Army Lt. Col. Charles Fitzgerald (right)
during a test run of one of the cyrillic teleprinters at the Pentagon terminal of the Hotline
At the left we see a black ETCRRM II encryption machine
(photo: AP, between 1963 and 1967)

The US terminals are manned by a team of military personnel, headed by a commissioned officer functioning as the Presidential Translator on duty. His primary job is to render into English all messages received through the Hot Line. When a message comes in, he makes a first sight translation to decide if it's so urgent that the president should be called on a secure line to give him an immediate oral translation.

If the Russian message is a bit less urgent, the Presidential Translator makes a rough written translation and sends that to the White House via a secure fax, but later a secure network channel. Later on, a final official translation of the message is made in cooperation with State Department translators.

James O'Beirne (left) and Benjamin W. Randal (right) using one of the personal computers
for sending a test message at the Pentagon Hotline terminal.
(photo: Time-Life/Scott Davis, November 14, 1985)

The 1985 presidential directive about the operation of the Direct Communications Link ordered two man-rule procedures to be established at all operating locations, to ensure against inadvertent release of the messages. Hotline messages may only be released with explicit approval of the president, and even releasing information about the sole fact whether this link has been used is a presidential prerogative.

Usage of the Hotline

The Washington-Moscow Hotline was mainly used to inform the other party about sudden movements of their fleet or troops, to prevent that the other could see that as a provocation or preparation of agression. Reportedly, the Hotline was first used by the Americans on the day of the assassination of president Kennedy, November 22, 1963, only a few months after the link was established.

The first time the Kremlin used the Hotline, was on June 5, 1967, when the Six-Day War broke out between Israel and some Arab countries. On that day Soviet prime minister Kosygin sent the following message, which was received in Washington at 7:59 AM:

The first message which the Soviets sent through the Hot Line, June 5, 1967
Left: message in Russian - right: translation in English
(click to enlarge)

This first message was followed by nineteen other transmissions during the Six-Day War of 1967, mostly to inform each other of the intentions and maneuvers of the Soviet Black Sea Fleet and the US 6th Fleet, which approached each other dangerously closely in the Mediterranean. Three of the messages were related to the incident with the American spy ship USS Liberty.

Later, the Hotline was also used during the following international conflicts:

- 1971: the war between India and Pakistan
- 1973: the Yom Kippur war
- 1974: the Turkish invasion of Cyprus
- 1979: the Russian invasion in Afghanistan
- 1981: the threat of a Russian invasion in Poland
- 1982: the Israeli invasion of Lebanon

In at least two cases, the Hotline was also used in non-crisis situations. President Johnson once ordered a message to be sent to the Soviet Union informing it of the American Apollo spaceship missions, and president Jimmy Carter used the Hotline for a more personal message to Sovjet leader Leonid Brezhnev, but the Russians didn't appreciate that and saw it as an improper use of the Direct Communications Link.

It is said that in 1986 president Ronald Reagan used the Hotline to threaten the Soviets over their arrest of the US journalist Nicholas Daniloff on espionage charges.

After the end of the Cold War and the collapse of the Sovjet Union in 1991 the Hotline between both super powers lost some of its significance. Also, world leaders tended more towards personal contacts, calling each other more often using a regular phone.*

Nevertheless, the Washington-Moscow Hotline was used by president George Bush sr. and Soviet leader Gorbachev to communicate during the Gulf War of 1991, and also the presidents George W. Bush and Vladimir Putin used it to discuss plans to rebuild Iraq after the Iraq War of 2003.*

Apparently there were also a few severe crisis situations in which the hotline wasn't used, like when on November 9, 1979 there was a false alarm at NORAD about what seemed to be a full-launch Soviet nuclear strike. Even more critical was the situation during the NATO exercise Able Archer 83 in November 1983, which made the Soviets think the US was preparing a nuclear war.


The phone calls which the American and Russian presidents make nowadays, are through the Direct Voice Link (DVL). That's a dedicated phone line between the White House and the office of the Russian president which uses the same satellite link as the Hotline. This phone line seems to be established by an agreement between the US and the Soviet Union in 1990, which was renewed for the Russian Federation in 1999.

The Direct Voice Link is meant for routine matters and the calls are usually scheduled in advance, so interpreters can be present.* This voice link is not part of the Washington-Moscow Hotline. By agreement only the latter is designated for top level crisis communications.

Red phones

The Washington-Moscow Hotline is often called the Red Phone, because many people think it's a phone line with a red handset on each side. As we have seen this was never the case - even though Wikipedia articles in almost every language say so up to this day.

Also president Obama used the popular myth of the red phone, when at a joint press conference in June 2010, he joked about how social media might help to move past the traditional Cold War communications. Speaking of the Russian president Medvedev starting a Twitter account, Obama said: "I have one, as well, so we may be able to finally throw away those red phones that have been sitting around for so long".

The image of the red phone is derived from many books and movies, in which world leaders call each other with a red phone to discuss a crisis, for example the 1964 movie Fail Safe, which was also based on the 1958 novel Red Alert. Because only very few people knew how the actual Hotline worked, also many US government officials assumed the direct communications link was a phone line.

This confusion is probably also caused by the fact that the White House and the military did use red phones, not for international, but for internal communications. Quick and easy contact between the president and the military command centers is of course just as important as contact with the Kremlin, and this is achieved through a secure military telephone network, called the Defense Red Switch Network (DRSN). For this network, a number of different handsets have been used, including a red one without a dial in the early years.* These real red phones will be discussed on this weblog later.

A more correct picture of a red telephone used for internal crisis communications was also seen in popular culture, like in the 1966 Batman television series (showing the Batphone) and the James Bond films, in which the head of MI6 uses a red phone to communicate with the prime minister and military officials.


1963: Establishment of a land line teletype link between the Kremlin and the Pentagon
1967: Ancillary terminal installed at the White House.
1978: The land line replaced by a satellite link.
1980: Old teletype and encryption machines replaced by newer ones.
1988: Teletype equipment replaced by facsimile units.
199?: Further modernizations
2008: E-mail capability established

Links and Sources

- 2019 ABC Australia: This Week in History: The Washington Moscow Hotline
- 2014 'I made Obama's BlackBerry'
- 2013 US Army article: Hotline, now 50 years old, continues to promote dialog with Russians
- 2013 Smithsonian article: There Never Was Such a Thing as a Red Phone in the White House
- 2013 Crypto Museum article: Washington-Moscow Hotline
- 2012 Wikipedia article in Dutch: Hotline Washington-Moskou
- 2011 article by the Voice of Russia: Hello, Mr. President!
- 2011 Matt's Today in History blog: Washington-Moscow Hotline Established, June 20, 1963
- 2008 article by Jerry Proc: The Washington-Moscow Hot Line
- 1988 New York Times article: Moscow's Still Holding
- 1963 New York Times article: 'Hot Line' Opened by U.S. and Soviet to Cut Attack Risk
- The original Hot Line Agreement Texts of 1963, 1971 and 1984

Documents (PDF)
- NSA, Cryptolog, December 1983: DCL, The Direct Communications Link (DCL), p. 21-27
- National Security Decision Directive nr. 186: Installation and Operation of the Direct Communications Link (DCL)/"Hotline" between Washington and Moscow, White House, 1985
- Jane Cunnion, Lycoming's Moscow Link, in: Lycoming Quarterly, December 1988, p. 2-3 (pdf page 12-13)
- Stephen L. Thacher, Crisis Communications between Superpowers, US Army War College, Carusle Barracks, 1990
- Stephen Soudakoff, Developing 3+/4 reading and translating skills for presidential needs: a summary, Distinguished Language Centers, 2002
- Haraldur Þór Egilsson, The Origins, Use and Development of Hot Line Diplomacy, Institute Clingendael, 2003
- Tobias Nanz, Communication in Crisis. The "Red Phone" and the "Hotline", Behemoth, A Journal on Civilisation, Issue Nr. 2, 2010

- Michael K. Bohn, Nerve Center. Inside the White House Situation Room, Brassey's Inc, Washington DC, 2003, p. 89-96.
- Paul E. Richardson, The hot line (is a Hollywood myth), in: Russian Life, September/October issue 2009, p. 50-59.
- Leland McCaslin, Secrets of the Cold War: US Army Europe's Intelligence and Counterintelligence Activities Against the Soviets, Helion, Solihull 2010, p. 111-114.

In Dutch: Meer over het wetsvoorstel voor de Tijdelijke wet cyberoperaties