Kasiski enlisted in East Prussia’s 33rd Infantry Regiment on 20 March, 1823 at the age of 17. In May 1824, he was promoted to the rank of Master Sergeant, and eight months later was commissioned as a Second Lieutenant in February 1825. It took fourteen years to earn his next promotion when, in May 1839, he advanced to the rank of First Lieutenant. His next advancement was quicker, promoted to Captain in November 1842. Kasiski finally retired from active service with the rank of Major on 17 February 1852.

Between 1860 and 1868 he was the commander of a National Guard battalion.

In 1863, Kasiski published a 95-page book on cryptography, Die Geheimschriften und die Dechiffrierkunst (German, “Secret writing and the Art of Deciphering”). This was the first published account of a procedure for attacking polyalphabetic substitution ciphers, especially the Vigenère cipher (although it is possible Charles Babbage was already aware of a similar method but had kept it secret). The method relied on the analysis of gaps between repeated fragments in the ciphertext; such analysis can give hints as to the length of the key used. This technique is known as Kasiski examination.

The significance of Kasiski’s cryptanalytic work was not widely realised at the time, and he turned his mind to archaeology instead. The later years of his life were spent at Neustettin (Szczecinek); the 11th edition of Encyclopædia Britannica cited a scholarly article by Kasiski in its entry on the town. Historian David Kahn notes, “Kasiski died on May 22, 1881, almost certainly without realizing that he had wrought a revolution in cryptology” (The Codebreakers)

While studying mathematics at Poznań University, Rejewski had attended a secret cryptology course conducted by the Polish General Staff’s Cipher Bureau, which he joined full-time in 1932. The Bureau had achieved little success reading Enigma and in late 1932 set Rejewski to work on the problem. After only a few weeks, he deduced the secret internal wiring of the Enigma. Rejewski and his two mathematician colleagues then developed an assortment of techniques for the regular decryption of Enigma messages. Rejewski’s contributions included devising the cryptologic “card catalog,” derived using his “cyclometer,” and the “cryptologic bomb.”

Five weeks before the German invasion of Poland in 1939, Rejewski and his colleagues presented their results on Enigma decryption to French and British intelligence representatives. Shortly after the outbreak of war, the Polish cryptologists were evacuated to France, where they continued their work in collaboration with the British and French. They were again compelled to evacuate after the fall of France in June 1940, but within months returned to work undercover in Vichy France. After the country was fully occupied by Germany in November 1942, Rejewski and fellow mathematician Henryk Zygalski fled, via Spain, Portugal and Gibraltar, to Britain. There they worked at a Polish Army unit, solving low-level German ciphers. In 1946 Rejewski returned to his family in Poland and worked as an accountant, remaining silent about his cryptologic work until 1967.

The concept of wearing a tin foil hat for protection from such threats has become a popular stereotype and term of derision; the phrase serves as a byword for paranoia and is associated with conspiracy theorists.

The reasons for their use include the supposed prevention of perceived harassment from governments, spies or paranormal beings. These draw on the stereotypical images of mind control operating by ESP or technological means, like microwave radiation. The effectiveness of tin foil hats is disputable; however, the belief in their necessity is popularly associated with paranoia or mental illness.

After becoming a cause célèbre from the late 1960s to the 1980s, the mythical Priory of Sion was exposed as a ludibrium created by Plantard as a framework for his false pretention to the French throne. Evidence presented in support of its historical existence and activities before 1956 was discovered to have been forged and then planted in various locations around France by Plantard and his accomplices. Nevertheless, many conspiracy theorists persist in believing that the Priory of Sion is an age-old cabal which conceals a subversive secret.

The Priory of Sion myth has been exhaustively debunked by journalists and scholars as one of the great hoaxes of the 20th century. Some skeptics have expressed concern that the proliferation and popularity of books, websites and films inspired by this hoax have contributed to the problem of conspiracy theories, pseudohistory and other confusions becoming more mainstream. Others are troubled by the romantic reactionary ideology unwittingly promoted in these works.

President George H. W. Bush, his son President George W. Bush, and the latter’s 2004 Presidential opponent Senator John Kerry are members of Skull and Bones.

Skull and Bones was founded in 1832 after a dispute among Yale’s debating societies, Linonia, Brothers in Unity, and Calliope, over that season’s Phi Beta Kappa awards; its original name was “the Order of Skull and Bones.”

The only chapter of Skull and Bones created outside Yale was a chapter at Wesleyan University in 1870. That chapter, the Beta of Skull & Bones, became independent in 1872 in a dispute over control over creating additional chapters; the Beta Chapter reconstituted itself as Theta Nu Epsilon.

For most of its history, Skull & Bones operated as a peer society with Scroll and Key and, later, Wolf’s Head, two of Yale’s other property-owning senior societies.

Skull and Bones owns a campground island in the St. Lawrence River in upstate New York named Deer Island. “The 40-acre (160,000 m²) retreat is intended to give Bonesmen an opportunity to ‘get together and rekindle old friendships.’ A century ago the island sported tennis courts and its softball fields were surrounded by rhubarb plants and gooseberry bushes. Catboats waited on the lake. Stewards catered elegant meals. Although each new Skull and Bones member still visits Deer Island, the place leaves something to be desired. ‘Now it is just a bunch of burned-out stone buildings,’ a patriarch sighs. ‘It’s basically ruins.’ Another Bonesman says that to call the island ‘rustic’ would be to glorify it. ‘It’s a dump, but it’s beautiful.’”

Yale became coeducational in 1969, but Skull & Bones remained all-male at the behest of the Russell Trust Association. The Class of 1991, however, disregarded the Trust and tapped seven female members for membership in the next year’s class. The Trust responded by changing the locks on the “Tomb”; the Bonesmen had to meet at the building of Manuscript Society. A mail-in vote by living members decided 368-320 to permit going co-ed, but a group of alumni led by William F. Buckley obtained a temporary restraining order to block the move, arguing that a formal change in bylaws was needed. Other alumni, such as John Kerry, spoke out in favor of admitting women, and the dispute even ended up on The New York Times editorial page. A second vote of alumni in October 1991 agreed to accept the Class of 1992, and the lawsuit was dropped. Wolf’s Head Society was the last all-male society at Yale.

Once the pinnacle of the college’s social system, the society remained central to campus life through the 1950s, but since then has lost much of its luster.

The fraternity is administratively organised into Grand Lodges (or sometimes Orients), each of which governs its own jurisdiction, which consists of subordinate (or constituent) Lodges. Grand Lodges recognise each other through a process of landmarks and regularity. There are also appendant bodies, which are organisations related to the main branch of Freemasonry, but with their own independent administration.

Freemasonry uses the metaphors of operative stonemasons’ tools and implements, against the allegorical backdrop of the building of King Solomon’s Temple, to convey what has been described by both Masons and critics as “a system of morality veiled in allegory and illustrated by symbols.”

The United States Air Force has stated that the theory is a hoax which “has been investigated and refuted by many established and accredited universities, scientific organizations, and major media publications”. The British Department for Environment, Food and Rural Affairs has stated that chemtrails “are not scientifically recognised phenomena”.^[5] The Canadian Government House Leader has stated that “The term ‘chemtrails’ is a popularized expression, and there is no scientific evidence to support their existence.”

The term chemtrail is derived from “chemical trail” in the similar fashion that contrail is an abbreviation for condensation trail. It does not refer to common forms of aerial spraying such as crop dusting, cloud seeding or aerial firefighting. The term specifically refers to aerial trails allegedly caused by the systematic high-altitude release of chemical substances not found in ordinary contrails, resulting in the appearance of supposedly uncharacteristic sky tracks. Believers of this theory speculate that the purpose of the chemical release may be for global dimming, population control, weather control, or biowarfare and claim that these trails are causing respiratory illnesses and other health problems.

The Council has been the subject of debate, as shown in the 2006 film by Aaron Russo, America: Freedom to Fascism and a 2007 documentary Zeitgeist, the Movie. This is partly due to the number of high-ranking government officials in its membership, along with world business leaders, its secrecy clauses, and the large number of aspects of American foreign policy that its members have been involved with, beginning with Wilson’s Fourteen Points. The John Birch Society believes that the CFR plans a one-world government. Wilson’s Fourteen Points speech was the first in which he suggested a worldwide security organization to prevent future world wars.

Historian Carroll Quigley included the CFR in his discussion of the Anglo-American Establishment’s efforts to shape international developments during the 20th century. His book “Tragedy and Hope” was cited by conspiracy theorists as showing that the CFR was engaged in a conspiracy against American interests, though Quigley himself denied this.

Systems theorists working with tools developed at MIT by Jay Forrester counter David Rockefeller’s support for his goals with the claim that an attempt to build an integrated global political and economic structure is a serious danger to humanity’s freedom and prosperity. They argue that a dearth of distributed systems on a global scale would mean, first, a globe more susceptible to total economic and/or resource calamity, and second, a world in which lack of competition between rival political systems would make totalitarianism—if ever globally established—extremely difficult to challenge. Supporting the former charge, they cite the recession of 2008, which was exacerbated by the global nature of capital and derivative markets, as an example of the dangers of extreme economic interdependence.

The phrase “black helicopters” is also sometimes used figuratively to ridicule conspiracy theories in general (see below).

In the United Kingdom, a similar phenomenon known as “phantom helicopters” has been reported since the mid 1970s. This concept relates phantom helicopters to UFOs and alien invasion rather than to martial law.