Counterintelligence ( counter-intelligence ) or counterespionage ( counter-espionage ) is any activity aimed at protecting an agency's intelligence program from an opposition's intelligence service. It includes gathering information and conducting activities to prevent espionage , sabotage , assassinations or other intelligence activities conducted by, for, or on behalf of foreign powers, organizations or persons.
141-710: The Venona project was a United States counterintelligence program initiated during World War II by the United States Army's Signal Intelligence Service and later absorbed by the National Security Agency (NSA), that ran from February 1, 1943, until October 1, 1980. It was intended to decrypt messages transmitted by the intelligence agencies of the Soviet Union (e.g. the NKVD , the KGB , and
282-403: A source into symbols for communication or storage. Decoding is the reverse process, converting code symbols back into a form that the recipient understands, such as English or/and Spanish. One reason for coding is to enable communication in places where ordinary plain language , spoken or written, is difficult or impossible. For example, semaphore , where the configuration of flags held by
423-486: A trained intuition possible connections and is trying to research them. Adding the new tools and techniques to [national arsenals], the counterintelligence community will seek to manipulate foreign spies, conduct aggressive investigations, make arrests and, where foreign officials are involved, expel them for engaging in practices inconsistent with their diplomatic status or exploit them as an unwitting channel for deception, or turn them into witting double agents. "Witting"
564-675: A BBC Radio correspondent, an MI6 intelligence officer, and as a member of the British Foreign Office. When the Korean War began, Burgess and Philby passed on information regarding movements in Korea to Moscow. Philby had been working closely with British and American intelligence, and was able to be in proximity to any intelligence findings. When the VENONA Project uncovered Julius Rosenberg (LIBERAL) and his wife Ethel,
705-639: A Labor government founding one seemed a surprising about-face. But the presentation of Venona material to Chifley, revealing evidence of Soviet agents operating in Australia, brought this about. As well as Australian diplomat suspects abroad, Venona had revealed Walter Seddon Clayton (cryptonym "KLOD"), a leading official within the Communist Party of Australia (CPA), as the chief organizer of Soviet intelligence gathering in Australia. Investigation revealed that Clayton formed an underground network within
846-525: A Soviet spy, writing "Hiss was indeed a Soviet agent and appears to have been regarded by Moscow as its most important." Kim Philby had access to CIA and FBI files, and more damaging, access to Venona Project briefings. When Philby learned of Venona in 1949, he obtained advance warning that his fellow Soviet spy Donald Maclean was in danger of being exposed. The FBI told Philby about an agent cryptonymed "Homer", whose 1945 message to Moscow had been decoded. As it had been sent from New York and had its origins in
987-464: A badly skewed impression." Counterintelligence Many countries will have multiple organizations focusing on a different aspect of counterintelligence, such as domestic, international, and counter-terrorism. Some states will formalize it as part of the police structure, such as the United States' Federal Bureau of Investigation (FBI). Others will establish independent bodies, such as
1128-459: A branch in Paris , run by Pyotr Rachkovsky , to monitor their activities. The agency used many methods to achieve its goals, including covert operations , undercover agents , and "perlustration"—the interception and reading of private correspondence. The Okhrana became notorious for its use of agents provocateurs , who often succeeded in penetrating the activities of revolutionary groups – including
1269-432: A corresponding sequence of amino acids that form a protein molecule; a type of codon called a stop codon signals the end of the sequence. In mathematics , a Gödel code was the basis for the proof of Gödel 's incompleteness theorem . Here, the idea was to map mathematical notation to a natural number (using a Gödel numbering ). There are codes using colors, like traffic lights , the color code employed to mark
1410-547: A daily basis. The interdependence of the US counterintelligence community is also manifest in its relationships with liaison services. The counterintelligence community cannot cut off these relationships because of concern about security, but experience has shown that it must calculate the risks involved. On the other side of the CI coin, counterespionage has one purpose that transcends all others in importance: penetration. The emphasis which
1551-516: A dozen Soviet sources each among their employees. Venona has added information – some unequivocal, some ambiguous – to several espionage cases. Some known spies, including Theodore Hall , were neither prosecuted nor publicly implicated, because the Venona evidence against them was withheld. The identity of the Soviet source cryptonymed "19" remains unclear. According to British writer Nigel West, "19"
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#17327874575381692-613: A first step in which the prisoner is given the choice of co-operating or facing severe consequence up to and including a death sentence for espionage. Co-operation may consist of telling all one knows about the other service but preferably actively assisting in deceptive actions against the hostile service. Defensive counterintelligence specifically for intelligence services involves risk assessment of their culture, sources, methods and resources. Risk management must constantly reflect those assessments, since effective intelligence operations are often risk-taking. Even while taking calculated risks,
1833-598: A front for the American Black Chamber run by Herbert Yardley between the First and Second World Wars. The purpose of most of these codes was to save on cable costs. The use of data coding for data compression predates the computer era; an early example is the telegraph Morse code where more-frequently used characters have shorter representations. Techniques such as Huffman coding are now used by computer-based algorithms to compress large data files into
1974-629: A group opposing a recognized government by criminal or military means, as well as conducting clandestine intelligence and covert operations against the government in question, which could be one's own or a friendly one. Counterintelligence and counterterrorism analyses provide strategic assessments of foreign intelligence and terrorist groups and prepare tactical options for ongoing operations and investigations. Counterespionage may involve proactive acts against foreign intelligence services, such as double agents , deception , or recruiting foreign intelligence officers. While clandestine HUMINT sources can give
2115-430: A key role in providing indications and warning of terrorist and other force protection threats. Code In communications and information processing , code is a system of rules to convert information —such as a letter , word , sound, image, or gesture —into another form, sometimes shortened or secret , for communication through a communication channel or storage in a storage medium . An early example
2256-597: A law enforcement framework. In France, a senior anti-terror magistrate is in charge of defense against terrorism. French magistrates have multiple functions that overlap US and UK functions of investigators, prosecutors, and judges. An anti-terror magistrate may call upon France's domestic intelligence service Direction générale de la sécurité intérieure (DGSI), which may work with the Direction générale de la sécurité extérieure (DGSE), foreign intelligence service. Spain gives its Interior Ministry, with military support,
2397-409: A low level of effort in the latter years) through 1980, when the Venona program was terminated. The analyst effort assigned to it was moved to more important projects. To what extent the various individuals referred to in the messages were involved with Soviet intelligence is a topic of minor historical dispute . Most academics and historians have established that most of the individuals mentioned in
2538-509: A maximum prison sentence of fourteen years. The Venona decryptions also identified Soviet spy Harry Gold as an agent of the KGB who stole blueprints, industrial formulas, and methods on their behalf from 1935 until ultimately confessing to these actions in 1950. During his years of work under the KGB, Gold operated under the code names GOOSE and ARNOLD. Gold was eager to provide his services after being initially recruited by Thomas Black on behalf of
2679-412: A more compact form for storage or transmission. Character encodings are representations of textual data. A given character encoding may be associated with a specific character set (the collection of characters which it can represent), though some character sets have multiple character encodings and vice versa. Character encodings may be broadly grouped according to the number of bytes required to represent
2820-652: A particular radio transmitter as one used only by a particular country, detecting that transmitter inside one's own country suggests the presence of a spy that counterintelligence should target. In particular, counterintelligence has a significant relationship with the collection discipline of HUMINT and at least some relationship with the others. Counterintelligence can both produce information and protect it. All US departments and agencies with intelligence functions are responsible for their own security abroad, except those that fall under Chief of Mission authority. Governments try to protect three things: In many governments,
2961-530: A principal, still acted as an accessory who took part in Julius's espionage activity and played a role in the recruitment of her brother for atomic espionage. Julius and Ethel Rosenberg also had another connection to a recruit for the Soviets named David Greenglass, who was Ethel's brother and Julius's brother-in-law. Venona and other recent information has shown that, while the content of Julius' atomic espionage
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#17327874575383102-658: A remote base in the Australian Outback . The Soviets remained unaware of this base as late as 1950. The founding of the Australian Security Intelligence Organisation (ASIO) by Labor Prime Minister Ben Chifley in 1949 was considered highly controversial within Chifley's own party. Until then, the left -leaning Australian Labor Party had been hostile to domestic intelligence agencies on civil-liberties grounds and
3243-546: A result, the National Anti-Terrorism Coordination Center was created. Spain's 3/11 Commission called for this center to do operational coordination as well as information collection and dissemination. The military has organic counterintelligence to meet specific military needs. Frank Wisner , a well-known CIA operations executive said of the autobiography of Director of Central Intelligence Allen W. Dulles , that Dulles "disposes of
3384-686: A role in aiding the Soviet atomic espionage campaign. According to the Moynihan Commission on Government Secrecy , the complicity of both Alger Hiss and Harry Dexter White is conclusively proven by Venona, stating "The complicity of Alger Hiss of the State Department seems settled. As does that of Harry Dexter White of the Treasury Department." In his 1998 book, United States Senator Daniel Patrick Moynihan expressed certainty about Hiss's identification by Venona as
3525-410: A sequence of target symbols. In this section, we consider codes that encode each source (clear text) character by a code word from some dictionary, and concatenation of such code words give us an encoded string. Variable-length codes are especially useful when clear text characters have different probabilities; see also entropy encoding . A prefix code is a code with the "prefix property": there
3666-461: A signaler or the arms of a semaphore tower encodes parts of the message, typically individual letters, and numbers. Another person standing a great distance away can interpret the flags and reproduce the words sent. In information theory and computer science , a code is usually considered as an algorithm that uniquely represents symbols from some source alphabet , by encoded strings, which may be in some other target alphabet. An extension of
3807-490: A significant amount of Trade traffic, recovering many one-time pad additive key tables in the process. A young Meredith Gardner then used this material to break into what turned out to be NKVD (and later GRU ) traffic by reconstructing the code used to convert text to numbers. Gardner credits Marie Meyer , a linguist with the Signal Intelligence Service with making some of the initial recoveries of
3948-659: A single character: there are single-byte encodings, multibyte (also called wide) encodings, and variable-width (also called variable-length) encodings. The earliest character encodings were single-byte, the best-known example of which is ASCII . ASCII remains in use today, for example in HTTP headers . However, single-byte encodings cannot model character sets with more than 256 characters. Scripts that require large character sets such as Chinese, Japanese and Korean must be represented with multibyte encodings. Early multibyte encodings were fixed-length, meaning that although each character
4089-411: A skunk!"), or AYYLU ("Not clearly coded, repeat more clearly."). Code words were chosen for various reasons: length , pronounceability , etc. Meanings were chosen to fit perceived needs: commercial negotiations, military terms for military codes, diplomatic terms for diplomatic codes, any and all of the preceding for espionage codes. Codebooks and codebook publishers proliferated, including one run as
4230-813: A warrant, etc. The Russian Federation 's major domestic security organization is the FSB , which principally came from the Second Chief Directorate and Third Chief Directorate of the USSR's KGB . Canada separates the functions of general defensive counterintelligence ( contre-ingérence ), security intelligence (the intelligence preparation necessary to conduct offensive counterintelligence), law enforcement intelligence, and offensive counterintelligence. Military organizations have their own counterintelligence forces, capable of conducting protective operations both at home and when deployed abroad. Depending on
4371-492: A wide range of functions, certainly including military or counterintelligence activities, but also humanitarian aid and aid to development ("nation building"). Terminology here is still emerging, and "transnational group" could include not only terrorist groups but also transnational criminal organization. Transnational criminal organizations include the drug trade, money laundering, extortion targeted against computer or communications systems, smuggling, etc. "Insurgent" could be
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4512-439: Is a total function mapping each symbol from S to a sequence of symbols over T. The extension C ′ {\displaystyle C'} of C {\displaystyle C} , is a homomorphism of S ∗ {\displaystyle S^{*}} into T ∗ {\displaystyle T^{*}} , which naturally maps each sequence of source symbols to
4653-466: Is a term of intelligence art that indicates that one is not only aware of a fact or piece of information but also aware of its connection to intelligence activities. Victor Suvorov , the pseudonym of a former Soviet military intelligence ( GRU ) officer, makes the point that a defecting HUMINT officer is a special threat to walk-in or other volunteer assets of the country that he is leaving. Volunteers who are "warmly welcomed" do not take into consideration
4794-428: Is active measures against those hostile services. This is often called counterespionage : measures taken to detect enemy espionage or physical attacks against friendly intelligence services, prevent damage and information loss, and, where possible, to turn the attempt back against its originator. Counterespionage goes beyond being reactive and actively tries to subvert hostile intelligence service, by recruiting agents in
4935-697: Is affecting the retrospective debate among historians and others now. As the Moynihan Commission wrote in its final report: A balanced history of this period is now beginning to appear; the Venona messages will surely supply a great cache of facts to bring the matter to some closure. But at the time, the American Government, much less the American public, was confronted with possibilities and charges, at once baffling and terrifying. The National Cryptologic Museum features an exhibit on
5076-410: Is an established term of art in the counterintelligence community, and, in today's world, "foreign" is shorthand for "opposing." Opposition might indeed be a country, but it could be a transnational group or an internal insurgent group. Operations against a FIS might be against one's own nation, or another friendly nation. The range of actions that might be done to support a friendly government can include
5217-485: Is an invention of language , which enabled a person, through speech , to communicate what they thought, saw, heard, or felt to others. But speech limits the range of communication to the distance a voice can carry and limits the audience to those present when the speech is uttered. The invention of writing , which converted spoken language into visual symbols , extended the range of communication across space and time . The process of encoding converts information from
5358-467: Is essential. Accordingly, each counterintelligence organization will validate the reliability of sources and methods that relate to the counterintelligence mission in accordance with common standards. For other mission areas, the USIC will examine collection, analysis, dissemination practices, and other intelligence activities and will recommend improvements, best practices, and common standards. Intelligence
5499-529: Is no valid code word in the system that is a prefix (start) of any other valid code word in the set. Huffman coding is the most known algorithm for deriving prefix codes. Prefix codes are widely referred to as "Huffman codes" even when the code was not produced by a Huffman algorithm. Other examples of prefix codes are country calling codes , the country and publisher parts of ISBNs , and the Secondary Synchronization Codes used in
5640-570: Is penetrated. A high-level defector can also do this, but the adversary knows that he defected and within limits can take remedial action. Conducting CE without the aid of penetrations is like fighting in the dark. Conducting CE with penetrations can be like shooting fish in a barrel . In the British service, the cases of the Cambridge Five , and the later suspicions about MI5 chief Sir Roger Hollis caused great internal dissension. Clearly,
5781-480: Is really specific to countering HUMINT , but, since virtually all offensive counterintelligence involves exploiting human sources, the term "offensive counterintelligence" is used here to avoid some ambiguous phrasing. Other countries also deal with the proper organization of defenses against Foreign Intelligence Services (FIS), often with separate services with no common authority below the head of government. France , for example, builds its domestic counterterror in
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5922-415: Is the focus of Project Slammer. Without undue violations of personal privacy, systems can be developed to spot anomalous behavior, especially in the use of information systems. Decision makers require intelligence free from hostile control or manipulation. Since every intelligence discipline is subject to manipulation by our adversaries, validating the reliability of intelligence from all collection platforms
6063-460: Is thwarting efforts by hostile intelligence services to penetrate the service. Offensive counterintelligence is having identified an opponent's efforts against the system, trying to manipulate these attacks by either "turning" the opponent's agents into double agents or feeding them false information to report. Many governments organize counterintelligence agencies separately and distinct from their intelligence collection services. In most countries
6204-705: Is vulnerable not only to external but also to internal threats. Subversion, treason, and leaks expose vulnerabilities, governmental and commercial secrets, and intelligence sources and methods. The insider threat has been a source of extraordinary damage to US national security, as with Aldrich Ames , Robert Hanssen , and Edward Lee Howard , all of whom had access to major clandestine activities. Had an electronic system to detect anomalies in browsing through counterintelligence files been in place, Robert Hanssen 's searches for suspicion of activities of his Soviet (and later Russian) paymasters might have surfaced early. Anomalies might simply show that an especially-creative analyst has
6345-588: The Amtorg . In 1935, Gold, with the assistance of Black, gained employment at the Pennsylvania Sugar Company, one of the largest producers of sugar in the world at the time. During his tenure, Gold worked under Semyon Semyonov and Klaus Fuchs . Over time, Gold began to work with Abraham Brothman, a fellow spy who was identified in Gold's confessions for stealing industrial processes on behalf of
6486-558: The Army-McCarthy hearings or rival politicians in the Democratic party, were not mentioned in the Venona content and that his accusations remain largely unsupported by evidence. The majority of historians are convinced of the historical value of the Venona material. Intelligence historian Nigel West believes that "Venona remain[s] an irrefutable resource, far more reliable than the mercurial recollections of KGB defectors and
6627-591: The Boers , the British government authorized the formation of a new intelligence section in the War Office , MO3 (subsequently redesignated MO5) headed by Melville, in 1903. Working under-cover from a flat in London, Melville ran both counterintelligence and foreign intelligence operations, capitalizing on the knowledge and foreign contacts he had accumulated during his years running Special Branch . Due to its success,
6768-569: The Bolsheviks . Integrated counterintelligence agencies run directly by governments were also established. The British government founded the Secret Service Bureau in 1909 as the first independent and interdepartmental agency fully in control over all government counterintelligence activities. Due to intense lobbying from William Melville and after he obtained German mobilization plans and proof of their financial support to
6909-744: The GRU ). Initiated when the Soviet Union was an ally of the US, the program continued during the Cold War , when the Soviet Union was considered an enemy. During the 37-year duration of the Venona project, the Signal Intelligence Service decrypted and translated approximately 3,000 messages. The signals intelligence yield included discovery of the Cambridge Five espionage ring in the United Kingdom and Soviet espionage of
7050-528: The Manhattan Project in the US (known as Project Enormous). Some of the espionage was undertaken to support the Soviet atomic bomb project . The Venona project remained secret for more than 15 years after it concluded. Some of the decoded Soviet messages were not declassified and published by the United States until 1995. During World War II and the early years of the Cold War , the Venona project
7191-706: The Military Intelligence Service at that time. Clarke distrusted Joseph Stalin , and feared that the Soviet Union would sign a separate peace with Nazi Germany , allowing Germany to focus its military forces against the United Kingdom and the United States. Cryptanalysts of the US Army's Signal Intelligence Service at Arlington Hall analyzed encrypted high-level Soviet diplomatic intelligence messages intercepted in large volumes during and immediately after World War II by American, British, and Australian listening posts. This message traffic, which
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#17327874575387332-813: The State Department , the Treasury, OSS, and even the White House. The messages show that the US and other nations were targeted in major espionage campaigns by the Soviet Union as early as 1942. Among those identified are Julius and Ethel Rosenberg , Alger Hiss , Harry Dexter White (the second-highest official in the Treasury Department), Lauchlin Currie (a personal aide to Franklin Roosevelt), and Maurice Halperin (a section head in
7473-687: The Sûreté générale —an agency originally responsible for order enforcement and public safety—and overseen by the Ministry of the Interior . The Okhrana initially formed in 1880 to combat political terrorism and left-wing revolutionary activity throughout the Russian Empire , was also tasked with countering enemy espionage. Its main concern was the activities of revolutionaries, who often worked and plotted subversive actions from abroad. It set up
7614-511: The UMTS WCDMA 3G Wireless Standard. Kraft's inequality characterizes the sets of codeword lengths that are possible in a prefix code. Virtually any uniquely decodable one-to-many code, not necessarily a prefix one, must satisfy Kraft's inequality. Codes may also be used to represent data in a way more resistant to errors in transmission or storage. This so-called error-correcting code works by including carefully crafted redundancy with
7755-621: The Unicode character set; UTF-8 is the most common encoding of text media on the Internet. Biological organisms contain genetic material that is used to control their function and development. This is DNA , which contains units named genes from which messenger RNA is derived. This in turn produces proteins through a genetic code in which a series of triplets ( codons ) of four possible nucleotides can be translated into one of twenty possible amino acids . A sequence of codons results in
7896-490: The 1943 GRU-Naval Washington to Moscow messages were broken, but none for any other year, although several thousand were sent between 1941 and 1945. The decryption rate of the NKVD cables was as follows: Out of some hundreds of thousands of intercepted encrypted texts, it is claimed under 3,000 have been partially or wholly decrypted. All the duplicate one-time pad pages were produced in 1942, and almost all of them had been used by
8037-587: The British Embassy in Washington, Philby, who would not have known Maclean's cryptonym, deduced the sender's identity. By early 1951, Philby knew US intelligence would soon also conclude Maclean was the sender and advised Moscow to extract Maclean. This led to Maclean and Guy Burgess' flight in May 1951 to Moscow, where they lived the remainder of their lives. Guy Burgess served as a British diplomat during
8178-749: The British Empire and the Russian Empire throughout Central Asia between 1830 and 1895. To counter Russian ambitions in the region and the potential threat it posed to the British position in India , the Indian Civil Service built up a system of surveillance, intelligence and counterintelligence. The existence of this shadowy conflict was popularized in Rudyard Kipling 's famous spy book , Kim (1901), where he portrayed
8319-567: The British were penetrated by Philby, but it has never been determined, in any public forum, if there were other serious penetrations. In the US service, there was also significant disruption over the contradictory accusations about moles from defectors Anatoliy Golitsyn and Yuri Nosenko , and their respective supporters in CIA and the British Security Service (MI5) . Golitsyn was generally believed by Angleton. George Kisevalter ,
8460-695: The CIA operations officer that was the CIA side of the joint US-UK handling of Oleg Penkovsky , did not believe Angleton's theory that Nosenko was a KGB plant. Nosenko had exposed John Vassall , a KGB asset principally in the British Admiralty, but there were arguments Vassall was a KGB sacrifice to protect other operations, including Nosenko and a possibly more valuable source on the Royal Navy. Defensive counterintelligence starts by looking for places in one's own organization that could easily be exploited by foreign intelligence services (FIS). FIS
8601-525: The CPA so that the party could continue to operate if it were banned. In 1950, George Ronald Richards was appointed ASIO's deputy-director of operations for Venona, based in Sydney, charged with investigating intelligence that uncovered the eleven Australians identified in the cables that had been decoded. He continued Venona-related work in London with MI5 from November 1952 and went on to lead Operation Cabin 12,
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#17327874575388742-775: The Government Committee on Intelligence, with support from Richard Haldane and Winston Churchill , established the Secret Service Bureau in 1909 as a joint initiative of the Admiralty , the War Office and the Foreign Office to control secret intelligence operations in the UK and overseas, particularly concentrating on the activities of the Imperial German government. Its first director
8883-472: The Great Game (a phrase Kipling popularized) as an espionage and intelligence conflict that "never ceases, day or night". The establishment of dedicated intelligence and counterintelligence organizations had much to do with the colonial rivalries between the major European powers and to the accelerating development of military technology. As espionage became more widely used, it became imperative to expand
9024-454: The KGB officer who controlled the clandestine Soviet agents in the US during the war, had said Hopkins was "the most important of all Soviet wartime agents in the United States". Alexander Vassiliev 's notes identified the source code-named "19" as Laurence Duggan . Venona has added significant information to the case of Julius and Ethel Rosenberg, making it clear Julius was guilty of espionage, and also showing that Ethel, while not acting as
9165-438: The KGB places on penetration is evident in the cases already discussed from the defensive or security viewpoint. The best security system in the world cannot provide an adequate defense against it because the technique involves people. The only way to be sure that an enemy has been contained is to know his plans in advance and in detail. Moreover, only a high-level penetration of the opposition can tell you whether your own service
9306-492: The Office of Strategic Services). The identification of individuals mentioned in Venona transcripts is sometimes problematic, since people with a "covert relationship" with Soviet intelligence are referenced by cryptonyms . Further complicating matters is the fact the same person sometimes had different cryptonyms at different times, and the same cryptonym was sometimes reused for different individuals. In some cases, notably Hiss,
9447-500: The Soviet Union and would later be convicted for lying under oath to a grand jury. Gold's confessions turned out to be a major success for the FBI, as he would unveil a network of spies entrenched in the success of KGB espionage efforts. Along with Brothman, (sentenced to 15 years), David Greenglass , and Julius Rosenburg were all arrested following the interrogations of Gold. With regard to Los Alamos , Fuchs, Greenglass, and Gold all played
9588-632: The Soviet Union from positions within the Manhattan Project. According to Alexander Vassiliev's notes from KGB archive, "Quantum" was Boris Podolsky and "Pers" was Russell W. McNutt, an engineer from the uranium processing plant in Oak Ridge . David Greenglass , codename KALIBER, was the brother of Ethel Rosenberg, and would be crucial in the conviction of the Rosenbergs. Greenglass was a former Army machinist who worked at Los Alamos. He
9729-470: The Soviet code generators started duplicating cipher pages in order to keep up with demand. It was Arlington Hall's Lieutenant Richard Hallock , working on Soviet "Trade" traffic (so called because these messages dealt with Soviet trade issues), who first discovered that the Soviets were reusing pages. Hallock and his colleagues, amongst whom were Genevieve Feinstein , Cecil Phillips , Frank Lewis , Frank Wanat , and Lucille Campbell , went on to break into
9870-419: The US Kim Philby , was told about the project in 1949, as part of his job as liaison between British and US intelligence. Since all of the duplicate one-time pad pages had been used by this time, the Soviets apparently did not make any changes to their cryptographic procedures after they learned of Venona. However, this information allowed them to alert those of their agents who might be at risk of exposure due to
10011-402: The United Kingdom's MI5 , others have both intelligence and counterintelligence grouped under the same agency, like the Canadian Security Intelligence Service (CSIS). Modern tactics of espionage and dedicated government intelligence agencies developed over the course of the late-19th century. A key background to this development was the Great Game – the strategic rivalry and conflict between
10152-462: The United States. Anti-Communists suspected many spies remained at large, perhaps including some known to the government. Those who criticized the governmental and non-governmental efforts to root out and expose Communists in the United States felt these efforts were an overreaction (in addition to other reservations about McCarthyism ). Public access—or broader governmental access—to the Venona evidence would certainly have affected this debate, as it
10293-565: The Venona codebook. Samuel Chew and Cecil Phillips also made valuable contributions. On December 20, 1946, Gardner made the first break into the code, revealing the existence of Soviet espionage in the Manhattan Project . Venona messages also indicated that Soviet spies worked in Washington in the State Department , Treasury , Office of Strategic Services (OSS), and even the White House . Very slowly, using assorted techniques ranging from traffic analysis to defector information, more of
10434-407: The Venona decrypts were probably either clandestine assets and/or contacts of Soviet intelligence agents, and very few argue that many of those people probably had no malicious intentions and committed no crimes. The VENONA Project was initiated on February 1, 1943, by Gene Grabeel , an American mathematician and cryptanalyst , under orders from Colonel Carter W. Clarke , Chief of Special Branch of
10575-577: The Venona project in its "Cold War/Information Age" gallery. Controversy arose in 2009 over the Texas State Board of Education's revision of their high school history class curricula to suggest Venona shows Senator Joseph McCarthy to have been justified in his zeal in exposing those whom he believed to be Soviet spies or communist sympathizers. Critics such as Emory University history professor Harvey Klehr assert most people and organizations identified by McCarthy, such as those brought forward in
10716-403: The White House's history of leaking sensitive information, decided to deny President Truman direct knowledge of the project. The president received the substance of the material only through FBI, Justice Department, and CIA reports on counterintelligence and intelligence matters. He was not told the material came from decoded Soviet ciphers. To some degree this secrecy was counter-productive; Truman
10857-464: The atom bomb to Gold and Rosenberg, who in turn passed it on to the Russians." In the end, Greenglass was sentenced to 15 years but was release in 1960 after serving only nine and a half. The Venona decryptions were also important in the exposure of the atomic spy Klaus Fuchs. Some of the earliest messages decrypted concerned information from a scientist at the Manhattan Project, who was referred to by
10998-421: The book's overconfidence in the translations' accuracy, noting that the undecrypted gaps in the texts can make interpretation difficult, and emphasizing the problem of identifying the individuals mentioned under cryptonyms. To support their critique, they cite a declassified memorandum, written in 1956 by A. H. Belmont, who was assistant to FBI director J. Edgar Hoover at the time. In the memo, Belmont discusses
11139-457: The code for representing sequences of symbols over the source alphabet is obtained by concatenating the encoded strings. Before giving a mathematically precise definition, this is a brief example. The mapping is a code, whose source alphabet is the set { a , b , c } {\displaystyle \{a,b,c\}} and whose target alphabet is the set { 0 , 1 } {\displaystyle \{0,1\}} . Using
11280-627: The code names of CHARLES and REST. Fuchs had joined the Manhattan Project at Los Alamos in 1944 where he provided information for the development of a plutonium implosion design. He is also credited with being of great assistance to the creation of a Soviet atomic bomb. Fuchs even gave the Soviets the blueprint for the Trinity device that would be detonated at Los Alamos in July 1945. One such message from Moscow to New York, dated April 10, 1945, called information provided by CHARLES "of great value." Noting that
11421-508: The code-breaking activity and had considerable knowledge of Venona and the counter-intelligence work that resulted from it. However, the first detailed account of the Venona project, identifying it by name and making clear its long-term implications in post-war espionage, was contained in MI5 assistant director Peter Wright 's 1987 memoir, Spycatcher . Many inside the NSA had argued internally that
11562-404: The confidentiality of communications, although ciphers are now used instead. Secret codes intended to obscure the real messages, ranging from serious (mainly espionage in military, diplomacy, business, etc.) to trivial (romance, games) can be any kind of imaginative encoding: flowers , game cards, clothes, fans, hats, melodies, birds, etc., in which the sole requirement is the pre-agreement on
11703-644: The counterintelligence mission is spread over multiple organizations, though one usually predominates. There is usually a domestic counterintelligence service, usually part of a larger law enforcement organization such as the Federal Bureau of Investigation in the United States . The United Kingdom has the separate Security Service , also known as MI5, which does not have direct police powers but works closely with law enforcement especially Special Branch that can carry out arrests, do searches with
11844-513: The country, there can be various mixtures of civilian and military in foreign operations. For example, while offensive counterintelligence is a mission of the US CIA 's National Clandestine Service , defensive counterintelligence is a mission of the U.S. Diplomatic Security Service (DSS), Department of State , who work on protective security for personnel and information processed abroad at US Embassies and Consulates. The term counter-espionage
11985-485: The cryptanalysis. The Finnish radio intelligence sold much of its material concerning Soviet codes to the OSS in 1944 during Operation Stella Polaris , including the partially burned code book. The NSA reported that (according to the serial numbers of the Venona cables) thousands of cables were sent, but only a fraction were available to the cryptanalysts. Approximately 2,200 messages were decrypted and translated; about half of
12126-523: The cryptographers have indicated that "almost anything included in a translation of one of these deciphered messages may in the future be radically revised." He also notes the complexities of identifying people with cryptonyms, describing how the personal details mentioned for cryptonym "Antenna" fit more than one person, and the investigative process required to finally connect "Antenna" to Julius Rosenberg. The Schneirs conclude that "A reader faced with Venona's incomplete, disjointed messages can easily arrive at
12267-490: The decryption. The decrypted messages gave important insights into Soviet behavior in the period during which duplicate one-time pads were used. With the first break into the code, Venona revealed the existence of Soviet espionage at the Manhattan Project's Site Y (Los Alamos) . Identities soon emerged of American, Canadian, Australian, and British spies in service to the Soviet government, including Klaus Fuchs , Alan Nunn May , and Donald Maclean. Others worked in Washington in
12408-508: The defections of Donald Maclean and Guy Burgess to the Soviet Union . Most decipherable messages were transmitted and intercepted between 1942 and 1945, during World War II, when the Soviet Union was an ally of the US. Sometime in 1945, the existence of the Venona program was revealed to the Soviet Union by cryptologist -analyst Bill Weisband , an NKVD agent in the US Army's SIGINT . These messages were slowly and gradually decrypted beginning in 1946. This effort continued (many times at
12549-458: The developing bomb project in the United States. He became a Soviet informant after beginning his studies at the University of Cambridge, where he and his classmates (Kim Philby, Anthony Blunt, and Donald Maclean) began developing ideals against a capitalist society. Burgess began developing connections throughout college as well as his future careers. He would continue to pass on information as
12690-568: The direction of James Jesus Angleton . Later, operational divisions had subordinate counterintelligence branches, as well as a smaller central counterintelligence staff. Aldrich Ames was in the Counterintelligence Branch of Europe Division, where he was responsible for directing the analysis of Soviet intelligence operations. US military services have had a similar and even more complex split. This kind of division clearly requires close coordination, and this in fact occurs on
12831-437: The dubious conclusions drawn by paranoid analysts mesmerized by Machiavellian plots." However, a number of writers and scholars have taken a critical view of the translations. They question the accuracy of the translations and the identifications of cryptonyms that the NSA translations give. Writers Walter and Miriam Schneir, in a lengthy 1999 review of one of the first book-length studies of the messages, object to what they see as
12972-455: The end of 1945, with a few being used as late as 1948. After this, Soviet message traffic reverted to being completely unreadable. The existence of Venona decryption became known to the Soviets within a few years of the first breaks. It is not clear whether the Soviets knew how much of the message traffic or which messages had been successfully decrypted. At least one Soviet penetration agent, British Secret Intelligence Service representative to
13113-444: The existing gap in national level coverage, as well as satisfying the combatant commander's intelligence requirements. Military police and other patrols that mingle with local people may indeed be valuable HUMINT sources for counterintelligence awareness, but are not themselves likely to be CFSOs. Gleghorn distinguishes between the protection of national intelligence services, and the intelligence needed to provide combatant commands with
13254-484: The extension of the code, the encoded string 0011001 can be grouped into codewords as 0 011 0 01, and these in turn can be decoded to the sequence of source symbols acab . Using terms from formal language theory , the precise mathematical definition of this concept is as follows: let S and T be two finite sets, called the source and target alphabets , respectively. A code C : S → T ∗ {\displaystyle C:\,S\to T^{*}}
13395-414: The fact that they are despised by hostile intelligence agents. The Soviet operational officer, having seen a great deal of the ugly face of communism, very frequently feels the utmost repulsion to those who sell themselves to it willingly. And when a GRU or KGB officer decides to break with his criminal organization, something which fortunately happens quite often, the first thing he will do is try to expose
13536-404: The first time, governments had access to peacetime, centralized independent intelligence and counterintelligence bureaucracy with indexed registries and defined procedures, as opposed to the more ad hoc methods used previously. Collective counterintelligence is gaining information about an opponent's intelligence collection capabilities whose aim is at an entity. Defensive counterintelligence
13677-427: The foreign service, by discrediting personnel actually loyal to their own service, and taking away resources that would be useful to the hostile service. All of these actions apply to non-national threats as well as to national organizations. If the hostile action is in one's own country or in a friendly one with co-operating police, the hostile agents may be arrested, or, if diplomats, declared persona non grata . From
13818-515: The former Soviet Union in Moscow to resolve questions of what was going on in Washington at mid-century. ... the Venona intercepts contained overwhelming proof of the activities of Soviet spy networks in America, complete with names, dates, places, and deeds. One of the considerations in releasing Venona translations was the privacy interests of the individuals mentioned, referenced, or identified in
13959-428: The greatest insight into the adversary's thinking, they may also be most vulnerable to the adversary's attacks on one's own organization. Before trusting an enemy agent, remember that such people started out as being trusted by their own countries and may still be loyal to that country. Wisner emphasized his own, and Dulles', views that the best defense against foreign attacks on, or infiltration of, intelligence services
14100-725: The hated volunteer. Attacks against military, diplomatic, and related facilities are a very real threat, as demonstrated by the 1983 attacks against French and US peacekeepers in Beirut, the 1996 attack on the Khobar Towers in Saudi Arabia, 1998 attacks on Colombian bases and on U.S. embassies (and local buildings) in Kenya and Tanzania the 2000 attack on the USS Cole , and many others. The U.S. military force protection measures are
14241-432: The high-profile 1953–1954 defection to Australia of Soviet spy Vladimir Petrov . For much of its history, knowledge of Venona was restricted even from the highest levels of government. Senior army officers, in consultation with the FBI and CIA, made the decision to restrict knowledge of Venona within the government (even the CIA was not made an active partner until 1952). Army Chief of Staff Omar Bradley , concerned about
14382-425: The infantry on the battlefield, etc. Communication systems for sensory impairments, such as sign language for deaf people and braille for blind people, are based on movement or tactile codes. Musical scores are the most common way to encode music . Specific games have their own code systems to record the matches, e.g. chess notation . In the history of cryptography , codes were once common for ensuring
14523-427: The information included "data on the atomic mass of the nuclear explosive" and "details on the explosive method of actuating" the atomic bomb, the message requested further technical details from CHARLES. Investigations based on the Venona decryptions eventually identified CHARLES and REST as Fuchs in 1949. Fuchs was eventually arrested and tried on March 1, 1950, where he confessed to four counts of espionage and received
14664-435: The information they need for force protection. There are other HUMINT sources, such as military reconnaissance patrols that avoid mixing with foreign personnel, that indeed may provide HUMINT, but not HUMINT especially relevant to counterintelligence. Active countermeasures, whether for force protection, protection of intelligence services, or protection of national security interests, are apt to involve HUMINT disciplines , for
14805-676: The leadership in domestic counterterrorism. For international threats, the National Intelligence Center (CNI) has responsibility. CNI, which reports directly to the Prime Minister, is staffed principally by which is subordinated directly to the Prime Minister's office. After the March 11, 2004 Madrid train bombings , the national investigation found problems between the Interior Ministry and CNI, and, as
14946-597: The matching of a Venona cryptonym to an individual is disputed. In many other cases, a Venona cryptonym has not yet been linked to any person. According to authors John Earl Haynes and Harvey Klehr , the Venona transcripts identify approximately 349 Americans who they claim had a covert relationship with Soviet intelligence, though fewer than half of these have been matched to real-name identities. However, not every agent may have been communicating directly with Soviet intelligence. Each of those 349 persons may have had many others working for, and reporting only to, them. The OSS,
15087-472: The meaning by both the sender and the receiver. Other examples of encoding include: Other examples of decoding include: Acronyms and abbreviations can be considered codes, and in a sense, all languages and writing systems are codes for human thought. International Air Transport Association airport codes are three-letter codes used to designate airports and used for bag tags . Station codes are similarly used on railways but are usually national, so
15228-457: The messages were decrypted. Claims have been made that information from the physical recovery of code books (a partially burned one was obtained by the Finns) to bugging embassy rooms in which text was entered into encrypting devices (analyzing the keystrokes by listening to them being punched in) contributed to recovering much of the plaintext. These latter claims are less than fully supported in
15369-509: The national to the field level. Counterintelligence is part of intelligence cycle security , which, in turn, is part of intelligence cycle management . A variety of security disciplines also fall under intelligence security management and complement counterintelligence, including: The disciplines involved in "positive security," measures by which one's own society collects information on its actual or potential security, complement security. For example, when communications intelligence identifies
15510-415: The nominal value of the electrical resistors or that of the trashcans devoted to specific types of garbage (paper, glass, organic, etc.). In marketing , coupon codes can be used for a financial discount or rebate when purchasing a product from a (usual internet) retailer. In military environments, specific sounds with the cornet are used for different uses: to mark some moments of the day, to command
15651-458: The one-time pad material had incorrectly been reused by the Soviets (specifically, entire pages, although not complete books), which allowed decryption (sometimes only partial) of a small part of the traffic. Generating the one-time pads was a slow and labor-intensive process, and the outbreak of war with Germany in June 1941 caused a sudden increase in the need for coded messages. It is probable that
15792-596: The open literature. One significant aid (mentioned by the NSA) in the early stages may have been work done in cooperation between the Japanese and Finnish cryptanalysis organizations; when the Americans broke into Japanese codes during World War II, they gained access to this information. There are also reports that copies of signals purloined from Soviet offices by the Federal Bureau of Investigation (FBI) were helpful in
15933-402: The partial message relating to "19" does not indicate whether this source was a spy. However, Vasili Mitrokhin was a KGB archivist who defected to the United Kingdom in 1992 with copies of large numbers of KGB files. He claimed Harry Hopkins was a secret Russian agent. Moreover, Oleg Gordievsky , a high-level KGB officer who also defected from the Soviet Union, reported that Iskhak Akhmerov ,
16074-447: The perspective of one's own intelligence service, exploiting the situation to the advantage of one's side is usually preferable to arrest or actions that might result in the death of the threat. The intelligence priority sometimes comes into conflict with the instincts of one's own law enforcement organizations, especially when the foreign threat combines foreign personnel with citizens of one's country. In some circumstances, arrest may be
16215-515: The popular misconception that counterintelligence is essentially a negative and responsive activity, that it moves only or chiefly in reaction to situations thrust upon it and in counter to initiatives mounted by the opposition." Rather, he sees that can be most effective, both in information gathering and protecting friendly intelligence services, when it creatively but vigorously attacks the "structure and personnel of hostile intelligence services." Today's counterintelligence missions have broadened from
16356-400: The possibility of using the Venona translations in court to prosecute Soviet agents and comes out strongly opposed to their use. His reasons include legal uncertainties about the admissibility of the translations as evidence, and the difficulties that prosecution would face in supporting the validity of the translations. Belmont highlights the uncertainties in the translation process, noting that
16497-661: The predecessor to the Central Intelligence Agency (CIA), housed at one time or another between fifteen and twenty Soviet spies. Duncan Lee , Donald Wheeler , Jane Foster Zlatowski , and Maurice Halperin passed information to Moscow. The War Production Board , the Board of Economic Warfare , the Office of the Coordinator of Inter-American Affairs , and the Office of War Information , included at least half
16638-484: The project posted that they knew of a British spy with the codename HOMER, which Philby knew to be Maclean. Philby (codename STANLEY) reached out to Burgess to remove Maclean to the Soviet Union. Burgess at this point, was overseas in Washington DC serving in the British Foreign Office, and couldn't do much. In 1950, he was sent back to Britain due to "bad behavior", where he was able to warn Maclean. Burgess knew he
16779-401: The purpose of detecting FIS agents, involving screening and debriefing of non-tasked human sources, also called casual or incidental sources. such as: Physical security is important, but it does not override the role of force protection intelligence... Although all intelligence disciplines can be used to gather force protection intelligence, HUMINT collected by intelligence and CI agencies plays
16920-506: The responsibility for protecting these things is split. Historically, CIA assigned responsibility for protecting its personnel and operations to its Office of Security, while it assigned the security of operations to multiple groups within the Directorate of Operations: the counterintelligence staff and the area (or functional) unit, such as Soviet Russia Division. At one point, the counterintelligence unit operated quite autonomously, under
17061-435: The reuse was detected by cryptanalysts in the US. The Soviet systems in general used a code to convert words and letters into numbers, to which additive keys (from one-time pads) were added, encrypting the content. When used correctly so that the plaintext is of a length equal to or less than that of a random key, one-time pad encryption is unbreakable. However, cryptanalysis by American code-breakers revealed that some of
17202-670: The role of existing police and internal security forces into a role of detecting and countering foreign spies. The Evidenzbureau (founded in the Austrian Empire in 1850) had the role from the late-19th century of countering the actions of the Pan-Slavist movement operating out of Serbia . After the fallout from the Dreyfus affair of 1894–1906 in France, responsibility for French military counter-espionage passed in 1899 to
17343-530: The same information to be sent with fewer characters , more quickly, and less expensively. Codes can be used for brevity. When telegraph messages were the state of the art in rapid long-distance communication, elaborate systems of commercial codes that encoded complete phrases into single mouths (commonly five-minute groups) were developed, so that telegraphers became conversant with such "words" as BYOXO ("Are you trying to weasel out of our deal?"), LIOUY ("Why do you not answer my question?"), BMULD ("You're
17484-404: The services need to mitigate risk with appropriate countermeasures. FIS are especially able to explore open societies and, in that environment, have been able to subvert insiders in the intelligence community. Offensive counterespionage is the most powerful tool for finding penetrators and neutralizing them, but it is not the only tool. Understanding what leads individuals to turn on their own side
17625-513: The set of actions taken against military personnel and family members, resources, facilities and critical information, and most countries have a similar doctrine for protecting those facilities and conserving the potential of the forces. Force protection is defined to be a defense against deliberate attack, not accidents or natural disasters. Counterintelligence Force Protection Source Operations (CFSO) are human source operations, normally clandestine in nature, conducted abroad that are intended to fill
17766-422: The stored (or transmitted) data. Examples include Hamming codes , Reed–Solomon , Reed–Muller , Walsh–Hadamard , Bose–Chaudhuri–Hochquenghem , Turbo , Golay , algebraic geometry codes , low-density parity-check codes , and space–time codes . Error detecting codes can be optimised to detect burst errors , or random errors . A cable code replaces words (e.g. ship or invoice ) with shorter words, allowing
17907-401: The time had come to publicly release the details of the Venona project, but it was not until 1995 that the bipartisan Commission on Government Secrecy, with Senator Moynihan as chairman, released Venona project materials. Moynihan wrote: [The] secrecy system has systematically denied American historians access to the records of American history. Of late we find ourselves relying on archives of
18048-580: The time when the threat was restricted to the foreign intelligence services (FIS) under the control of nation-states. Threats have broadened to include threats from non-national or trans-national groups, including internal insurgents, organized crime, and transnational based groups (often called "terrorists", but that is limiting). Still, the FIS term remains the usual way of referring to the threat against which counterintelligence protects. In modern practice, several missions are associated with counterintelligence from
18189-486: The translations. Some names were not released because to do so would constitute an invasion of privacy. However, in at least one case, independent researchers identified one of the subjects whose name had been obscured by the NSA. The dearth of reliable information available to the public—or even to the President and Congress—may have helped to polarize debates of the 1950s over the extent and danger of Soviet espionage in
18330-463: The work of Indian revolutionaries collaborating with the Germans during the war. Instead of a system whereby rival departments and military services would work on their own priorities with little to no consultation or cooperation with each other, the newly established Secret Intelligence Service was interdepartmental, and submitted its intelligence reports to all relevant government departments. For
18471-670: Was Captain Sir George Mansfield Smith-Cumming alias "C". The Secret Service Bureau was split into a foreign and counter-intelligence domestic service in 1910. The latter, headed by Sir Vernon Kell , originally aimed at calming public fears of large-scale German espionage. As the Service was not authorized with police powers, Kell liaised extensively with the Special Branch of Scotland Yard (headed by Basil Thomson ), and succeeded in disrupting
18612-597: Was Edvard Beneš , president of the Czechoslovak government-in-exile . Military historian Eduard Mark and American authors Herbert Romerstein and Eric Breindel concluded it was Roosevelt's aide Harry Hopkins . According to American authors John Earl Haynes and Harvey Klehr, "19" could be someone from the British delegation to the Washington Conference in May 1943. Moreover, they argue no evidence of Hopkins as an agent has been found in other archives, and
18753-507: Was a source of information on Soviet intelligence-gathering directed at the Western military powers. Although unknown to the public, and even to Presidents Franklin D. Roosevelt and Harry S. Truman , these programs were of importance concerning crucial events of the early Cold War. These included the Julius and Ethel Rosenberg spying case (which was based on events during World War II) and
18894-408: Was distrustful of FBI head J. Edgar Hoover and suspected the reports were exaggerated for political purposes. Some of the earliest detailed public knowledge that Soviet code messages from World War II had been broken came with the release of Chapman Pincher 's book, Too Secret Too Long , in 1984. Robert Lamphere 's book, The FBI-KGB War , was released in 1986. Lamphere had been the FBI liaison to
19035-422: Was encrypted with a one-time pad system, was stored and analyzed in relative secrecy by hundreds of cryptanalysts over a 40-year period starting in the early 1940s. When used correctly, the one-time pad encryption system, which has been used for all the most-secret military and diplomatic communication since the 1930s, is unbreakable. However, due to a serious blunder on the part of the Soviets, some of this traffic
19176-530: Was not as vital to the Soviets as alleged at the time of his espionage activities, in other fields it was extensive. The information Rosenberg passed to the Soviets concerned the proximity fuze , design and production information on the Lockheed P-80 jet fighter, and thousands of classified reports from Emerson Radio . The Venona evidence indicates unidentified sources code-named "Quantum" and "Pers" who facilitated transfer of nuclear weapons technology to
19317-406: Was originally meant to replace a soldier who had gone AWOL, and lied on his security clearance in order to gain access onto the project. Once Klaus Fuchs was caught, he gave up Harry Gold, who in turn, gave up Greenglass and his wife, as well as his sister and her husband. During their trial, Greenglass changed his story several times. At first, he didn't want to implicate his sister, but when his wife
19458-500: Was represented by more than one byte, all characters used the same number of bytes ("word length"), making them suitable for decoding with a lookup table. The final group, variable-width encodings, is a subset of multibyte encodings. These use more complex encoding and decoding logic to efficiently represent large character sets while keeping the representations of more commonly used characters shorter or maintaining backward compatibility properties. This group includes UTF-8 , an encoding of
19599-519: Was threatened, he gave up both of them. According to Gerald Markowitz and Michael Meeropol, "In the Rosenberg-Sobell case, the government relied heavily upon the testimony of Greenglass, who pleaded guilty to conspiracy to commit espionage in exchange for a reduced sentence for himself and no indictment or prosecution for his wife, Ruth, who he alleged had aided him in committing espionage. Greenglass testified that he had passed information about
19740-411: Was under suspicion by MI5, British counterintelligence, and Scotland Yard's Special Branch. Both Philby and Burgess knew that out of all of the possible people to crack under pressure, Maclean was the easy choice. When Burgess finally convinced Maclean to leave, they fled to Moscow, followed by Philby shortly after. In addition to British and American operatives, Australians collected Venona intercepts at
19881-481: Was vulnerable to cryptanalysis. The Soviet company that manufactured the one-time pads produced around 35,000 pages of duplicate key numbers, as a result of pressures brought about by the German advance on Moscow during World War II. The duplication—which undermines the security of a one-time system—was discovered, and attempts to lessen its impact were made by sending the duplicates to widely separated users. Despite this,
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