Cryptanalysis refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown.
William Frederick Friedman was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. In 1940, subordinates of his led by Frank Rowlett broke Japan's PURPLE cipher, thus disclosing Japanese diplomatic secrets before America's entrance into World War II.
Articles related to cryptography include:
Cryptography, the use of codes and ciphers to protect secrets, began thousands of years ago. Until recent decades, it has been the story of what might be called classical cryptography — that is, of methods of encryption that use pen and paper, or perhaps simple mechanical aids. In the early 20th century, the invention of complex mechanical and electromechanical machines, such as the Enigma rotor machine, provided more sophisticated and efficient means of encryption; and the subsequent introduction of electronics and computing has allowed elaborate schemes of still greater complexity, most of which are entirely unsuited to pen and paper.
Brigadier John Hessell Tiltman, was a British Army officer who worked in intelligence, often at or with the Government Code and Cypher School (GC&CS) starting in the 1920s. His intelligence work was largely connected with cryptography, and he showed exceptional skill at cryptanalysis. His work in association with Bill Tutte on the cryptanalysis of the Lorenz cipher, the German teleprinter cipher, called "Tunny" at Bletchley Park, led to breakthroughs in attack methods on the code, without a computer. It was to exploit those methods, at extremely high speed with great reliability, that Colossus, the first digital programmable electronic computer, was designed and built.
The Intelligence Bureau (IB) is India's internal security and counterintelligence agency under the Ministry of Home Affairs. It was founded in 1887 as the Central Special Branch. The IB is often regarded as the oldest extant intelligence organisation in the world.
Cryptography was used extensively during World War II because of the importance of radio communication and the ease of radio interception. The nations involved fielded a plethora of code and cipher systems, many of the latter using rotor machines. As a result, the theoretical and practical aspects of cryptanalysis, or codebreaking, were much advanced.
The Ministry of Defence (MoD) is charged with coordinating and supervising all agencies and functions of the government relating directly to national security and the Indian Armed Forces. The President of India is the ceremonial commander-in-chief of the armed forces of the country. The Ministry of Defence provides policy framework and resources to the armed forces to discharge their responsibility in the context of the country's defence. The Indian Armed Forces and Indian Coast Guard under the Ministry of Defence are primarily responsible for ensuring the territorial integrity of India.
With the rise of easily-intercepted wireless telegraphy, codes and ciphers were used extensively in World War I. The decoding by British Naval intelligence of the Zimmermann telegram helped bring the United States into the war.
The Deuxième Bureau de l'État-major général was France's external military intelligence agency from 1871 to 1940. It was dissolved together with the Third Republic upon the armistice with Germany. However the term "Deuxième Bureau", like "MI6" and "KGB", outlived the original organization as a general label for the country's intelligence service.
Cryptography, or cryptology, is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications.
The following outline is provided as an overview of and topical guide to cryptography:
The Cipher Department of the High Command of the Wehrmacht was the Signal Intelligence Agency of the Supreme Command of the Armed Forces of the German Armed Forces before and during World War II. OKW/Chi, within the formal order of battle hierarchy OKW/WFsT/Ag WNV/Chi, dealt with the cryptanalysis and deciphering of enemy and neutral states' message traffic and security control of its own key processes and machinery, such as the rotor cipher ENIGMA machine. It was the successor to the former Chi bureau of the Reichswehr Ministry.
The Government of the United Kingdom maintains several intelligence agencies that deal with secret intelligence. These agencies are responsible for collecting, analysing and exploiting foreign and domestic intelligence, providing military intelligence, and performing espionage and counter-espionage. Their intelligence assessments contribute to the conduct of the foreign relations of the United Kingdom, maintaining the national security of the United Kingdom, military planning, public safety, and law enforcement in the United Kingdom. The four main agencies are the Secret Intelligence Service, the Security Service (MI5), the Government Communications Headquarters (GCHQ) and Defence Intelligence (DI). The agencies are organised under three government departments, the Foreign Office, the Home Office and the Ministry of Defence.
The Pers Z S was the signals intelligence agency of the German Foreign Office before and during World War II. It consisted of two cryptologic sections. Pers Z S was the cryptanalytic section which was called Special Service of Z Branch of the Foreign Office Personnel Department. Its mission was the solution of foreign diplomatic codes and ciphers. The other section, which was the Cryptography Section was called Personal Z Cipher Service of the Federal Foreign Office. The latter section was responsible for compilation, distribution and security of Foreign Office codes and ciphers. Both were colloquially known as Pers Z S. Though similar in nature and operation to the OKW/Chi cipher bureau, it was a civilian operation as opposed to the military operation at OKW/Chi and focused primarily on diplomatic communications. According to TICOM interrogators it evinced an extraordinary degree of competence, primarily driven by a consistency of development not found in any other German signals bureau of the period. Pers Z S/Chi was the symbol and the code name of the Chiffrierdienst, i.e. the Cryptanalysis Department of Pers Z S. Although little is known about the organization, in the final analysis, Pers Z S labored at diplomatic cryptanalysis for a regime for which there were no diplomatic solutions.
Wilhelm Fenner was a German cryptanalyst, before and during the time of World War II in the OKW/Chi, the Cipher Department of the High Command of the Wehrmacht, working within the main cryptanalysis group, and entrusted with deciphering enemy message traffic (Cryptography). Wilhelm Fenner was considered an excellent organizer, an anti-Nazi, an anti-Bolshevik and a confirmed Protestant and was known by colleagues as someone who was keen to continue working in cryptology after World War II. To quote military historian David Alvarez:
Ostwin Fritz Menzer was a German cryptologist, who before and during World War II, worked in the In 7/VI, the Wehrmacht signals intelligence agency, later working in that was the cipher bureau of the supreme command of the Nazi party, and later in Abwehr, the military intelligence service of the Wehrmacht. He was involved in the development and production of cryptographic devices and procedures, as well as the security control of their own methods.
General der Nachrichtenaufklärung Training Referat was the training organization within the General der Nachrichtenaufklärung (GDNA), the military signals intelligence agency of the Wehrmacht during World War II. Initially established from May 1941, it continued teaching until September 1944. Until 1942, the work of the Training Referat was not fully exploited and only a small beginners course was taught.
The Integrated Defence Staff (IDS) is an organisation responsible for fostering coordination and enabling prioritisation across the different branches of the Indian Armed Forces. It is composed of representatives from the Indian Army, Indian Navy, Indian Air Force, Ministry of External Affairs, Defence Research and Development Organisation (DRDO), Ministry of Defence and Ministry of Finance. The IDS is headed by Chief of Integrated Defence Staff along with Deputy Chiefs of Integrated Defence Staff. On December 24, 2019, the Cabinet Committee on Security (CCS) established the post of Chief of Defence Staff, a four-star general, a tri-service Chief, that shall lead the defence forces as well as play the role of head of the Department of Military Affairs. The body advises and assists the Chief of Defence Staff.
