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🔗 Internet 🔗 Computing 🔗 Cryptography 🔗 Numismatics 🔗 Numismatics/Cryptocurrency 🔗 Computing/Computer Security

SHA-3 (Secure Hash Algorithm 3) is the latest member of the Secure Hash Algorithm family of standards, released by NIST on August 5, 2015. Although part of the same series of standards, SHA-3 is internally different from the MD5-like structure of SHA-1 and SHA-2.

SHA-3 is a subset of the broader cryptographic primitive family Keccak (), designed by Guido Bertoni, Joan Daemen, Michaël Peeters, and Gilles Van Assche, building upon RadioGatún. Keccak's authors have proposed additional uses for the function, not (yet) standardized by NIST, including a stream cipher, an authenticated encryption system, a "tree" hashing scheme for faster hashing on certain architectures, and AEAD ciphers Keyak and Ketje.

Keccak is based on a novel approach called sponge construction. Sponge construction is based on a wide random function or random permutation, and allows inputting ("absorbing" in sponge terminology) any amount of data, and outputting ("squeezing") any amount of data, while acting as a pseudorandom function with regard to all previous inputs. This leads to great flexibility.

NIST does not currently plan to withdraw SHA-2 or remove it from the revised Secure Hash Standard. The purpose of SHA-3 is that it can be directly substituted for SHA-2 in current applications if necessary, and to significantly improve the robustness of NIST's overall hash algorithm toolkit.

The creators of the Keccak algorithms and the SHA-3 functions suggest using the faster function KangarooTwelve with adjusted parameters and a new tree hashing mode without extra overhead for small message sizes.

🔗 Maps 🔗 Turkey 🔗 Paranormal

The Piri Reis map is a world map compiled in 1513 by the Ottoman admiral and cartographer Piri Reis (pronounced [piːˈɾiː ɾeis]). Approximately one third of the map survives; it shows the western coasts of Europe and North Africa and the coast of Brazil with reasonable accuracy. Various Atlantic islands, including the Azores and Canary Islands, are depicted, as is the mythical island of Antillia and possibly Japan.

The map's historical importance lies in its demonstration of the extent of global exploration of the New World by approximately 1510, and in its claim to have used a map of Christopher Columbus, otherwise lost, as a source. Piri also stated that he had used ten Arab sources and four Indian maps sourced from the Portuguese. More recently, the map has been the focus of claims for the pre-modern exploration of the Antarctic coast.

The Piri Reis map is in the Library of the Topkapı Palace in Istanbul, Turkey, but is not usually on display to the public.

🔗 Military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/World War I 🔗 Military history/German military history 🔗 Birds 🔗 Photography 🔗 Photography/History of photography 🔗 Military history/European military history

Pigeon photography is an aerial photography technique invented in 1907 by the German apothecary Julius Neubronner, who also used pigeons to deliver medications. A homing pigeon was fitted with an aluminium breast harness to which a lightweight time-delayed miniature camera could be attached. Neubronner's German patent application was initially rejected, but was granted in December 1908 after he produced authenticated photographs taken by his pigeons. He publicized the technique at the 1909 Dresden International Photographic Exhibition, and sold some images as postcards at the Frankfurt International Aviation Exhibition and at the 1910 and 1911 Paris Air Shows.

Initially, the military potential of pigeon photography for aerial reconnaissance appeared interesting. Battlefield tests in World War I provided encouraging results, but the ancillary technology of mobile dovecotes for messenger pigeons had the greatest impact. Owing to the rapid perfection of aviation during the war, military interest in pigeon photography faded and Neubronner abandoned his experiments. The idea was briefly resurrected in the 1930s by a Swiss clockmaker, and reportedly also by the German and French militaries. Although war pigeons were deployed extensively during World War II, it is unclear to what extent, if any, birds were involved in aerial reconnaissance. The United States Central Intelligence Agency (CIA) later developed a battery-powered camera designed for espionage pigeon photography; details of its use remain classified.

The construction of sufficiently small and light cameras with a timer mechanism, and the training and handling of the birds to carry the necessary loads, presented major challenges, as did the limited control over the pigeons' position, orientation and speed when the photographs were being taken. In 2004, the British Broadcasting Corporation (BBC) used miniature television cameras attached to falcons and goshawks to obtain live footage, and today some researchers, enthusiasts and artists similarly deploy crittercams with various species of animals.

🔗 Systems 🔗 Time 🔗 Systems/Chaos theory

A digital sundial is a clock that indicates the current time with numerals formed by the sunlight striking it. Like a classical sundial, the device contains no moving parts. It uses no electricity nor other manufactured sources of energy. The digital display changes as the sun advances in its daily course.

🔗 Systems 🔗 Politics 🔗 Socialism 🔗 Sociology 🔗 Globalization

World-systems theory (also known as world-systems analysis or the world-systems perspective) is a multidisciplinary, macro-scale approach to world history and social change which emphasizes the world-system (and not nation states) as the primary (but not exclusive) unit of social analysis.

"World-system" refers to the inter-regional and transnational division of labor, which divides the world into core countries, semi-periphery countries, and the periphery countries. Core countries focus on higher skill, capital-intensive production, and the rest of the world focuses on low-skill, labor-intensive production and extraction of raw materials. This constantly reinforces the dominance of the core countries. Nonetheless, the system has dynamic characteristics, in part as a result of revolutions in transport technology, and individual states can gain or lose their core (semi-periphery, periphery) status over time. This structure is unified by the division of labour. It is a world-economy rooted in a capitalist economy. For a time, certain countries become the world hegemon; during the last few centuries, as the world-system has extended geographically and intensified economically, this status has passed from the Netherlands, to the United Kingdom and (most recently) to the United States.

World-systems theory has been examined by many political theorists and sociologists to explain the reasons for the rise and fall of nations, income inequality, social unrest, and imperialism.

The photophone is a telecommunications device that allows transmission of speech on a beam of light. It was invented jointly by Alexander Graham Bell and his assistant Charles Sumner Tainter on February 19, 1880, at Bell's laboratory at 1325 L Street in Washington, D.C. Both were later to become full associates in the Volta Laboratory Association, created and financed by Bell.

On June 3, 1880, Bell's assistant transmitted a wireless voice telephone message from the roof of the Franklin School to the window of Bell's laboratory, some 213 meters (about 700 ft.) away.

Bell believed the photophone was his most important invention. Of the 18 patents granted in Bell's name alone, and the 12 he shared with his collaborators, four were for the photophone, which Bell referred to as his "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone".

The photophone was a precursor to the fiber-optic communication systems that achieved worldwide popular usage starting in the 1980s. The master patent for the photophone (U.S. Patent 235,199 Apparatus for Signalling and Communicating, called Photophone) was issued in December 1880, many decades before its principles came to have practical applications.

🔗 Military history 🔗 Military history/North American military history 🔗 Military history/United States military history 🔗 Military history/Military science, technology, and theory 🔗 Military history/Intelligence 🔗 Military history/Cold War 🔗 Military history/Australia, New Zealand and South Pacific military history 🔗 Military history/Canadian military history 🔗 Military history/European military history 🔗 Military history/British military history

The Five Eyes (FVEY) is an anglophone intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom and the United States. These countries are parties to the multilateral UKUSA Agreement, a treaty for joint cooperation in signals intelligence.

The origins of the FVEY can be traced back to the post–World War II period, when the Atlantic Charter was issued by the Allies to lay out their goals for a post-war world. During the course of the Cold War, the ECHELON surveillance system was initially developed by the FVEY to monitor the communications of the former Soviet Union and the Eastern Bloc, although it is now used to monitor billions of private communications worldwide.

In the late 1990s, the existence of ECHELON was disclosed to the public, triggering a major debate in the European Parliament and, to a lesser extent, the United States Congress. As part of efforts in the ongoing War on Terror since 2001, the FVEY further expanded their surveillance capabilities, with much emphasis placed on monitoring the World Wide Web. The former NSA contractor Edward Snowden described the Five Eyes as a "supra-national intelligence organisation that does not answer to the known laws of its own countries". Documents leaked by Snowden in 2013 revealed that the FVEY has been spying on one another's citizens and sharing the collected information with each other in order to circumvent restrictive domestic regulations on surveillance of citizens.

In spite of continued controversy over its methods, the Five Eyes relationship remains one of the most comprehensive known espionage alliances in history.

Since processed intelligence is gathered from multiple sources, the intelligence shared is not restricted to signals intelligence (SIGINT) and often involves defence intelligence as well as human intelligence (HUMINT) and geospatial intelligence (GEOINT). The following table provides an overview of most of the FVEY agencies involved in such forms of data sharing.

🔗 Computing 🔗 Computer science 🔗 Cryptography 🔗 Cryptography/Computer science

Diffie–Hellman key exchange is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as conceived by Ralph Merkle and named after Whitfield Diffie and Martin Hellman. DH is one of the earliest practical examples of public key exchange implemented within the field of cryptography.

Traditionally, secure encrypted communication between two parties required that they first exchange keys by some secure physical means, such as paper key lists transported by a trusted courier. The Diffie–Hellman key exchange method allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an insecure channel. This key can then be used to encrypt subsequent communications using a symmetric key cipher.

Diffie–Hellman is used to secure a variety of Internet services. However, research published in October 2015 suggests that the parameters in use for many DH Internet applications at that time are not strong enough to prevent compromise by very well-funded attackers, such as the security services of large governments.

The scheme was published by Whitfield Diffie and Martin Hellman in 1976, but in 1997 it was revealed that James H. Ellis, Clifford Cocks, and Malcolm J. Williamson of GCHQ, the British signals intelligence agency, had previously shown in 1969 how public-key cryptography could be achieved.

Although Diffie–Hellman key agreement itself is a non-authenticated key-agreement protocol, it provides the basis for a variety of authenticated protocols, and is used to provide forward secrecy in Transport Layer Security's ephemeral modes (referred to as EDH or DHE depending on the cipher suite).

The method was followed shortly afterwards by RSA, an implementation of public-key cryptography using asymmetric algorithms.

Expired U.S. Patent 4,200,770 from 1977 describes the now public-domain algorithm. It credits Hellman, Diffie, and Merkle as inventors.

🔗 Computer science

In computer science, the Knuth–Morris–Pratt string-searching algorithm (or KMP algorithm) searches for occurrences of a "word" W within a main "text string" S by employing the observation that when a mismatch occurs, the word itself embodies sufficient information to determine where the next match could begin, thus bypassing re-examination of previously matched characters.

The algorithm was conceived by James H. Morris and independently discovered by Donald Knuth "a few weeks later" from automata theory. Morris and Vaughan Pratt published a technical report in 1970. The three also published the algorithm jointly in 1977. Independently, in 1969, Matiyasevich discovered a similar algorithm, coded by a two-dimensional Turing machine, while studying a string-pattern-matching recognition problem over a binary alphabet. This was the first linear-time algorithm for string matching.

🔗 Companies 🔗 Computing 🔗 United Kingdom

Andrews & Arnold Ltd (also known as AAISP) is an Internet service provider based in Bracknell in the United Kingdom founded in 1997 and launched in 1998, primarily serving businesses and "technical" home users.

In 2009 the company was judged the best niche provider in the Thinkbroadband Customer Service Awards, based on customer ratings and again in 2010.

The company's owner, Adrian Kennard (RevK), stated in a blog post that as of October 2010 the company is "xkcd/806" compliant, referring to xkcd comic number 806. This means that technical support callers who say the code word "shibboleet" will be transferred to a technical support representative who knows at least two programming languages, and presumably can offer more useful advice than a standard tech support script.

Andrews & Arnold provides IPv6 to all customers, for no additional charge.

Andrews & Arnold provides optional bonded multiple-link internet access. This allows multiple links to be used together to vastly increase speed and reliability. Special routers distribute individual IP packets between the available links in such a way that even one single download or upload operation will benefit fully from multiple speed, and it is not necessary to have several users, several running programs or computers to gain the speed benefit. Links can be of different types, each needs only to be a pipe that can carry IP packets. Multiple links can either be used together all the time, or some can be brought up as a back up if other links fail, so-called 'failover', or a combination of the two approaches can be set up.

Andrews & Arnold are strong advocates of not censoring Internet connections. Adrian Kennard has several blog posts discussing why Internet censorship as discussed in the UK is not workable, providing background for AAISP's decision.