AcharyaChanakya/simple-wikipedia huggingface dataset:
The concept of genetic algorithms is a search technique often used in computer science to find complex, non-obvious solutions to algorithmic optimisation and search problems. Genetic algorithms are global search heuristics.
Natural evolution can be modeled as a game, in which the rewards for an organism that plays a good game of life are the passing on of its genetic material to its successors and its continued survival. In natural evolution, how well an individual performs depends on its who it works with and who it competes with, as well as the environment. Genetic algorithms are a simulation of natural selection on a population of candidate solutions to an optimization problem (chromosomes, individuals, creatures, or phenotypes).
Candidates are evaluated and crossbred in an attempt to make good solutions. Such solutions may take a lot of time and are not obvious to a human. An evolutionary phase is started with a population of randomly generated beings. In each generation, the fitness of every individual in the population is evaluated. Some are randomly selected from the current population (based on their fitness) and modified (recombined and possibly randomly mutated) to form a new population. The cycle repeats with this new population. The algorithm ends either after a set number of generations have passed, or a good fitness level has been reached for the population. If the algorithm has ended due to reaching a maximum number of generations, it does not necessarily mean a good fitness level has been obtained.
The pseudocode is:
The above description is abstract. A concrete example helps.
Genetic algorithms are good at solving problems that include timetabling and scheduling. They have also been applied to engineering. They are often used to solve global optimization problems.
As a general rule of thumb, genetic algorithms might be useful in problem domains that have a complex fitness landscape as mixing is designed to move the population away from local optima that a traditional hill climbing algorithm might get stuck in. Commonly used crossover operators cannot change any uniform population. Mutation alone can provide ergodicity of the overall genetic algorithm process (seen as a Markov chain).
Examples of problems solved by genetic algorithms include: mirrors designed to funnel sunlight to a solar collector, antennae designed to pick up radio signals in space, walking methods for computer figures, optimal design of aerodynamic bodies in complex flowfields
In his "Algorithm Design Manual", Skiena advises against genetic algorithms for any task: ""It is quite unnatural to model applications in terms of genetic operators like mutation and crossover on bit strings. The pseudobiology adds another level of complexity between you and your problem. Second, genetic algorithms take a very long time on nontrivial problems. [...] The analogy with evolution—where significant progress require [sic] millions of years—can be quite appropriate.
[...] I have never encountered any problem where genetic algorithms seemed to me the right way to attack it. Further, I have never seen any computational results reported using genetic algorithms that have favorably impressed me. Stick to simulated annealing for your heuristic search voodoo needs.""
Board games are a very relevant part of the area of genetic algorithms as applied to game theory problems. Much of the early work on computational intelligence and games was directed toward classic board games, such as tic-tac-toe, chess, and checkers. Board games can now, in most cases, be played by a computer at a higher level than the best humans, even with blind exhaustive search techniques. Go is a noted exception to this tendency, and has so far resisted machine attack. The best Go computer players now play at the level of a good novice. Go strategy is said to rely heavily on pattern recognition, and not just logical analysis as with chess and other more piece-independent games. The huge effective branching factor required for finding high quality solutions heavily restricts the look-ahead that can be used within a move sequence search.
The genetic algorithm can be used in computer games to create artificial intelligence (the computer plays against you). This allows for a more realistic game experience; if a human player can find a sequence of steps which always lead to success even when repeated in different games, there can be no challenge left. Conversely if a learning technique such as a genetic algorithm for a strategist can avoid repeating past mistakes, the game will have more playability.
Genetic algorithms require the following parts:
The fitness function accepts a mutated instantiation of an entity and measures its quality. This function is customized to the problem domain. In many cases, particularly those involving code optimization, the fitness function may simply be a system timing function. Once a genetic representation and fitness function are defined, a genetic algorithm will instantiate initial candidates as described before, and then improve through repetitive application of mutation, crossover, inversion and selection operators (as defined according to the problem domain).
There are limitations of the use of a genetic algorithm compared to alternative optimization algorithms:
In 1950, Alan Turing proposed a "learning machine" which would parallel the principles of evolution. Computer simulation of evolution started as early as in 1954 with the work of Nils Aall Barricelli, who was using the computer at the Institute for Advanced Study in Princeton, New Jersey. His 1954 publication was not widely noticed. Starting in 1957, the Australian quantitative geneticist Alex Fraser published a series of papers on simulation of artificial selection of organisms with multiple loci controlling a measurable trait. From these beginnings, computer simulation of evolution by biologists became more common in the early 1960s, and the methods were described in books by Fraser and Burnell (1970) and Crosby (1973). Fraser's simulations included all of the essential elements of modern genetic algorithms. In addition, Hans-Joachim Bremermann published a series of papers in the 1960s that also adopted a population of solution to optimization problems, undergoing recombination, mutation, and selection. Bremermann's research also included the elements of modern genetic algorithms. Other noteworthy early pioneers include Richard Friedberg, George Friedman, and Michael Conrad. Many early papers are reprinted by Fogel (1998).
Although Barricelli, in work he reported in 1963, had simulated the evolution of ability to play a simple game, artificial evolution became a widely recognized optimization method as a result of the work of Ingo Rechenberg and Hans-Paul Schwefel in the 1960s and early 1970s – Rechenberg's group was able to solve complex engineering problems through evolution strategies. Another approach was the evolutionary programming technique of Lawrence J. Fogel, which was proposed for generating artificial intelligence. Evolutionary programming originally used finite state machines for predicting environments, and used variation and selection to optimize the predictive logics. Genetic algorithms in particular became popular through the work of John Holland in the early 1970s, and particularly his book "Adaptation in Natural and Artificial Systems" (1975). His work originated with studies of cellular automata, conducted by Holland and his students at the University of Michigan. Holland introduced a formalized framework for predicting the quality of the next generation, known as Holland's schema theorem. Research in GAs remained largely theoretical until the mid-1980s, when The First International Conference on Genetic Algorithms was held in Pittsburgh, Pennsylvania.
Ingo Rechenberg
"Ingo Rechenberg"' (born January 20 1934 in Berlin) is a German computer scientist and professor. Rechenberg is a pioneer of the fields of evolutionary computation and artificial evolution. In the 1960s and 1970s he invented a highly influential set of optimization methods known as evolution strategies (from German "Evolutionsstrategie"). His group successfully applied the new algorithms to challenging problems such as aerodynamic wing design. These were the first serious technical applications of artificial evolution, an important subset of the still growing field of bionics.
Rechenberg was educated at the Technical University of Berlin and at the University of Cambridge. Since 1972 he has been a full professor at the Technical University of Berlin, where he is heading the Department of Bionics and Evolution Techniques.
His awards include the Lifetime Achievement Award of the Evolutionary Programming Society (US, 1995) and the Evolutionary Computation Pioneer Award of the IEEE Neural Networks Society (US, 2002). In 1954, Rechenberg also became world champion in the field of model airplanes.
Evolution strategy
John Henry Holland
John Henry Holland (February 2, 1929 – August 9, 2015) was an American scientist. He was Professor of Psychology and Professor of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor. He was a pioneer in complex system and nonlinear science. He was known as the father of genetic algorithms.
Holland died on August 9, 2015 in Ann Arbor, Michigan, aged 86.
Ontario Lacus
Ontario Lacus is a lake filled with methane and ethane near the south pole of Saturn's moon Titan. It was identified as a hydrocarbon lake and confirmed by data from the Cassini spacecraft. This discovery was announced in the 31 July 2008 edition of "Nature". Ontario Lacus is about 20,000 km in area, and is named after Lake Ontario in North America, which is a similar size and shape.
Penetrometer
A penetrometer is a device to test the strength of a material.
It is often used on soil. The penetrometer is dropped on soil or it is pressed against soil to measure how deep a hole it makes. This is a way to decide if soil is strong enough to build a road on. Scientists can use a penetrometer to measure how much moisture is in soil. Penetrometers are used on space probes such as the Cassini-Huygens probe, to measure the amount of moisture in soil on other planets.
Crème brûlée (or Crème brulée) is a dessert. It is made of custard. It is topped with a thin, brittle crust of caramelized sugar. It may be served cold, warm, or at room temperature. The custard is baked, and then sprinkled with sugar Casa that is caramelized under a broiler or with a kitchen blowtorch. The custard is flavored with vanilla. Other flavorings include chocolate, orange liqueur, fruit, or other. The caramelized sugar crust can be covered with a liqueur and set on fire.
The exact origin of crème brûlée is uncertain. France, England, and Spain all claim to be the country where crème brûlée had its origin. The first printed recipe for a dessert called crème brûlée is from the 1691 edition of the French cookbook "Le Cuisinier Royal et Bourgeois" by Francois Massialot, a cook at the Palace of Versailles. That version was a sweet custard of egg yolks and milk with a burnt sugar crust. It is similar to the modern versions. In the second edition of the book, the dessert is called "crème anglaise".
At Trinity College, Cambridge the dessert was known as 'burnt cream'. The college crest was burnt into sugar on top of a custard using a hot iron. It may predate Massialot's cookbook with one authority claiming it was first served at Trinity in 1630.
Catalans claim their dessert known as "crema catalana" is the original. It is a rich custard often flavoured with cinnamon and lemon or orange zest topped with carmelized sugar. The Catalan version was first recorded in the 18th century. It is also called "Crema de Sant Josep", after Saint Joseph, the husband of the Virgin Mary. In Spain and in many other parts of Europe, Saint Joseph’s Day is celebrated on 19 March. "Crema Catalana" is a traditional dessert served on this day.
Kraken Mare is the largest known lake on the surface of Saturn's moon Titan. It was discovered in 2007 by the Cassini probe and was named in 2008 after the Kraken, a legendary sea monster.
Kraken Mare is believed to be the largest of seas and lakes near Titan's north pole. It was discovered as a sea of hydrocarbons by radar pictures. Only a small part of the sea has been pictured by radar, but its full size is seen in visible light pictures. Kraken Mare is believed to be similar in size to the Caspian Sea.
An island in the sea is named Mayda Insula.
Ligeia Mare
Ligeia Mare is a lake on Titan at 79.0° N, 248.0° W, measuring around 500 km in width. It is named after Ligeia, one of the sirens in Greek mythology. Ligeia Mare has been a proposed lake to land the Titan Lake In-situ Sampling Propelled Explorer space probe
In cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a plaintext message to produce an encrypted message (the ciphertext).
The "characters" in the keystream can be bits, bytes, numbers or actual characters like A-Z depending on the usage case.
Usually each character in the keystream is either added, subtracted or XORed with a character in the plaintext to produce the ciphertext, using modular arithmetic.
Keystreams are used in the one-time pad cipher and in most stream ciphers. Block ciphers can also be used to produce keystreams. For example, the CTR mode (also known as Integer Counter Mode (ICM)) is a block mode that makes a block cipher produce a keystream then turns the block cipher into a stream cipher.
In this simple example we will use only the English alphabet of 26 characters from a-z, therefore we will not encrypt numbers, commas, spaces and other symbols. As we have only 26 characters the random numbers in the keystream have to be at least between 0 and 25.
To encrypt we add the keystream numbers to the plaintext. And to decrypt we subtract the same keystream numbers from the ciphertext to get the plaintext.
If a ciphertext number becomes larger than 25 we wrap it to a value between 0-25. I.e. 26 becomes 0 and 27 becomes 1 and so on. (Such wrapping is called modular arithmetic.)
Here the plaintext message "attack at dawn" is combined by addition with the keystream "kjcngmlhylyu" and produces the ciphertext "kcvniwlabluh".
Noor Jehan
Noor Jehan () was the adopted stage name for Allah Wasai (September 21, 1926 – December 23, 2000). She was a Pakistani singer and actress. She is renowned as one of the greatest singers of her time in the Indian subcontinent and was given the honorific title of "Mallika-e-Tarranum" (, English: the queen of melody). She achieved special national recognition and popularity in Pakistan with her patriotic songs of 1965, which elevated her to an iconic level.
Along with Ahmed Rushdi, she holds the record for having given voice to the largest number of film songs in the history of Pakistani cinema. She is also considered to be the first female Pakistani film director.
Noor Jehan was awarded the Pakistan President's Award in 1965.
She married Shaukat Hussain Rizvi in 1942. The marriage ended in 1953 with divorce. The couple had three children, including their singer daughter Zil-e-Huma. She then married Ejaz Durrani in 1959. The second marriage also produced three children. It ended in divorce in 1970.
In 2000, Jehan was hospitalized in Karachi and suffered a heart attack. Jehan died as a result of heart failure.
Nusrat Fateh Ali Khan (, October 13, 1948 – August 16, 1997), was a Pakistani musician. He was a singer of qawwali, the devotional music of the Sufis (a mystical tradition in Islam). In 2006, "Time" magazine included him in their list of "Asian Heroes'.
Traditionally, qawwali is a performing art which is passed down with in the family. Nusrat's family has been performing qawwali for the last 600 years. Among other honorary titles given to him, Nusrat was called "Shahenshah-e-Qawwali", meaning "The Emperor of Qawwali".
Aziz Mian
Aziz Mian Qawwal () (April 17, 1942 – December 6, 2000) was a Pakistani singer, most famous for his performing of Qawwalis. Aziz Mian was born as Abdul Aziz () in Delhi, British India. The exclamation "Mian", which he often used in his qawwalis, became part of his stage name. He began to introduce himself as Aziz Mian Mairthi. The word "Mairthi" refers to Meerut, a city in northern India, from which he migrated to Pakistan in 1947.
At the age of ten, he began learning the art of Qawwali under the tutelage of Ustad Abdul Wahid Khan. He received sixteen years of training at the Data Ganj Baksh School of Lahore, and obtained a degree in Urdu literature from the University of Punjab, Lahore.
Kashmir Solidarity Day
Kashmir Solidarity Day has been celebrated on 5 February each year since 1990. It is a day of protest against Indian control of part of Kashmir. It is a national holiday in Pakistan.
National emblem of Bangladesh
The National Emblem of Bangladesh was adopted shortly after independence in 1971.
Located on the emblem is a White water lily, that is bordered on two sides by rice sheaves. Above the water lilly are four stars and a three-leaf clover of jute leaves. The water lily is the country's national flower, and is representative of the many rivers that run through Bangladesh. Rice represents its presence as the staple food of Bangladesh, and for the agriculture of that nation. The four stars represent the four founding principles that were originally enshrined in the first constitution of Bangladesh in 1972: Nationalism, Secularism, Socialism, and Democracy.
The details of the emblem is given as quoted below:
"The national emblem of the Republic is the national flower Shapla (Nymphaea pubescens) resting on water, having on each side an ear of paddy and being surmounted by three connected leaves of jute with two stars on each side of the leaves." - Constitution of Bangladesh Article 4(3)
The Government of Bangladesh has adopted Education, Nationalism and Democracy as its ""National Motto"".
Instrument of Surrender
The Instrument of Surrender () was a written agreement that enabled the surrender of the Pakistan Armed Forces in the Bangladesh Liberation War. The surrender took place at the Ramna Race Course in Dacca on December 16, 1971. Lieutenant-General A A K Niazi, joint commander of the Pakistan Armed Forces in East Pakistan, and Lieutenant General Jagjit Singh Aurora, joint commander of the Bangladesh-India Allied Forces, signed the instrument amid thousands of cheering crowds at the race course. Air Commodore A. K. Khandker, Deputy Commander-in-Chief of the Bangladesh Armed Forces, and Lieutenant General J F R Jacob of the Indian Eastern Command, acted as witnesses to the surrender.
Subsequently, around 93,000 Pakistani troops and officials were taken as prisoners-of-war by the Indian Army, the largest number of POWs since World War II. They were later repatriated in 1973 under the terms of the Delhi Agreement.
The Pakistan Eastern Command agree to surrender all Pakistan Armed Forces in Bangladesh to Lieutenant-General Jagjit Singh Aurora, General Officer Commanding in Chief of the Indian and Bangladesh forces in the Eastern Theatre. This surrender includes all Pakistan land, air and naval forces as also all para-military forces and civil armed forces. These forces will lay down their arms and surrender at the places where they are currently located to the nearest regular troops under the command of Lieutenant- General Jagjit Singh Aurora.
The Pakistan Eastern Command shall come under the orders of Lieutenant-General Jagjit Singh Aurora as soon as this instrument has been signed. Disobedience of orders will be regarded as a breach of the surrender terms and will be dealt with in accordance with the accepted laws and usages of war. The decision of Lieutenant-General Jagjit Singh Aurora will be final, should any doubt arise as to the meaning or interpretation of the surrender terms.
Lieutenant- General Jagjit Singh Aurora gives a solemn assurance that personnel who surrender will be treated with dignity and respect that soldiers are entitled to in accordance with the provisions of the Geneva Convention and guarantees the safety and well-being of all PAKISTAN military and para-military forces who surrender. Protection will be provided to foreign nationals, ethnic minorities and personnel of Western Pakistan origin by the forces under the command of Lieutenant - General Jagjit Singh Aurora.
Signed:
(Jagjit Singh Aurora) Lieutenant-General General Officer Commanding in Chief Indian and Bangladesh Forces in the Eastern Theatre
(Amir Abdullah Khan Niazi) Lieutenant-General Martial Law Administrator Zone B and Commander Eastern Command (Pakistan)
16 December 1971"
This document can be seen on display in the National Museum in Delhi (as of January 2012)
Product cipher
In cryptography, a product cipher is a popular type of stream ciphers that works by executing in sequence a number of simple transformations such as substitution, permutation, and modular arithmetic.
Product ciphers usually consist of iterations of several "rounds" of the same algorithm. Individual "rounds" themselves are not secure. However, it is hoped that a sufficiently long chain of "rounds" loads the cipher with sufficient confusion and diffusion properties to make it resistant to cryptanalysis.
A product cipher that uses only substitutions and permutations is called a SP-network. Feistel ciphers are another important class of product ciphers.
Islamic Republic
Islamic Republic is the name given to forms of government of several states. These states often have Islam as a state religion and are governed by the principles of Sharia, islamic law. Laws made by the state cannot contradict Sharia.
The following states call themselves Islamic Republic (non-exhaustive list)
Despite the similar name the countries differ greatly in their governments and laws.
In cryptography, the so-called product ciphers are a certain kind of ciphers, where the decryption of data is done in ""rounds"". The general setup of each "round" is the same, except for some hard-coded parameters and a part of the cipher key, called a subkey. A key schedule is an algorithm that, given the key, calculates the subkeys for these "rounds".
Knudsen and Mathiassen (2004) give some experimental evidence that indicate that the key schedule plays a part in providing strength against linear and differential cryptanalysis. For toy Feistel ciphers, it was observed that those with complex and well-designed key schedules can reach a uniform distribution for the probabilities of differentials and linear hulls faster than those with poorly-designed key schedules.
EFF DES cracker
In cryptography, the EFF DES cracker (nicknamed "Deep Crack") is a machine built by the Electronic Frontier Foundation (EFF) to perform a brute force search of DES cipher's key space — that is, to decrypt an encrypted message by trying every possible key. The aim in doing this was to prove that DES's key is not long enough to be secure.
The DES uses a 56-bit key, meaning that there are 2 possible keys under which a message can be encrypted. This is approximately 7.21 (more than 72 quadrillion). When DES was approved as a federal standard in 1976, a machine fast enough to test such a number of keys in a reasonable time would have cost an unreasonable amount of money to build.
Classified information is sensitive information to which access is restricted by law or regulation to particular classes of people. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation. There are typically several levels of sensitivity, with differing clearance requirements. This sort of hierarchical system of sharing information among a group of people is almost used by every national government. The operation of assigning the level of sensitivity to data is called data classification.
The purpose of classification is to protect information from being used to damage or cause danger to national security. Classification formalizes what constitutes a "state secret" and deals with different levels of protection based on the expected damage the information might cause if it reached the wrong hands.
Certain non-government organizations and corporations also have their own secret information, normally referred to as trade secrets.
Although the classification systems vary from country to country, most have levels corresponding to the following British definitions (from the highest level to lowest):
Depending on the level of classification there are different rules controlling the level of clearance needed to view such information, and how it must be stored, transmitted, and destroyed. Additionally, access is restricted on a "need to know" basis. Simply possessing a clearance does not automatically authorize the individual to view all material classified at that level or below that level. The individual must present a legitimate "need to know" in addition to the proper level of clearance.
A security clearance is a status granted (approved) to individuals allowing them access to classified information, e.g. state secrets. It is something like permission or a license. The term "security clearance" is also sometimes used in private organizations that have a formal process of selecting employees to access ""sensitive information"".
A clearance by itself is normally not sufficient to gain access; the organization must determine that the cleared person ""needs to know"" the information. No one is supposed to be granted access to classified information only because of rank, position, or a security clearance.
Sensitive information
Sensitive information is information or knowledge that might result in loss of an advantage or level of security if exposed to others who might be unfriends or have low or unknown trustability.
Loss, misuse, modification or unauthorized access to sensitive information can negatively affect the privacy of an individual, trade secrets of a business or even the security, internal and foreign affairs of a nation depending on the level of sensitivity and nature of the information.
The term classified information generally refers to information that is subject to special security classification regulations imposed by many national governments. The term "Unclassified" as used in the below refers to information that is not subject to security classification regulations. Information can be reclassified to a different level or declassified (made available to the public) depending on changes of situation or new intelligence.
Trade secret
A trade secret is a formula, practice, process, design, instrument, pattern, or a collection of information which is not generally known, invented or created, by which a business can obtain an economic advantage over competitors or customers. In some jurisdictions, such secrets are referred to as "confidential information" or "classified information".
With its broad definition of eligible subject matter, trade secret law protects a wide range of valuable information, including information that would not be eligible for protection under existing patent, trademark, or copyright law. This could include formulae and recipes, proprietary databases, business processes and methods, information about costs, pricing, margins, overhead, manufacturing processes, proprietary computer software programs, customer lists, and strategic plans and marketing programs.
There are three factors that are common to all definitions of a trade secret, a trade secret is information that:
The unauthorized acquisition, use, or disclosure of such secret information in a manner contrary to honest commercial practices by others is regarded as an unfair practice and a violation of the trade secret protection.
Rock Steady is the fifth studio album by the American alternative rock band No Doubt. It was released on December 11, 2001. The album was influenced a lot by reggae, dancehall, and electronica, compared to their previous albums. A lot of music critics saw this and gave the album good reviews. For example, "Rolling Stone" magazine put the album as the 316th greatest album of all time in their book "Rolling Stone's List of the 500 Greatest Albums of All Time". It was nominated for Best Pop Vocal Album at the 2003 Grammy Awards. Four singles were released from the album. The first single, "Hey Baby", won the Grammy Award for Best Pop Performance by a Duo or Group with Vocal. The second single was nominated for Best Dance Recording. The third single, "Underneath It All", was released August 15 2002. It won a Grammy Award for Best Pop Performance by a Duo or Group with Vocal at the 2004 Grammy Awards. The album's last single, "Running", was released July 1 2003.
The iTunes version of the album has two extra songs.
Meet-in-the-middle attack
The Meet-in-the-middle attack is a cryptographic attack which, like the birthday attack, makes use of a space-time tradeoff. While the birthday attack attempts to find two values in the domain of a function that map to the same value in its range, the meet-in-the-middle attack attempts to find a value in each of the ranges and domains of the composition of two functions such that the forward mapping of one through the first function is the same as the inverse image of the other through the second function—quite literally meeting in the middle of the composed function.
It was first developed as an attack on an attempted expansion of a block cipher by Diffie and Hellman in 1977. When trying to improve the security of a block cipher, one might get the idea to simply use two independent keys to encrypt the data twice and think that this would square the security of the double-encryption scheme. Certainly, an exhaustive search of all possible combination of keys would take formula_1 attempts if each key is n bits long, compared to the formula_2 attempts required for a single key. However, Diffie and Hellman, discovered a time-memory tradeoff that could break the scheme in only double the time to break the single-encryption scheme. The attack works by encrypting from one end and decrypting from the other end, thus meeting in the middle.
Assume the attacker knows a set of plaintext and ciphertext: "P" and "C". That is,
where E is the encryption function (cipher), and "K" and "K" are the two keys.
The attacker can then compute "E"("P") for all possible keys "K" and store the results in memory. Afterwards he can decrypt the ciphertext by computing "D"("C") for each "K". Any matches between these two resulting sets are likely to reveal the correct keys. (To speed up the comparison, the "E"("P") set is stored in an in-memory lookup table, then each "D"("C") can be matched against the values in the lookup table to find the candidate keys.)
Once the matches are discovered, they can be verified with a second test-set of plaintext and ciphertext. If the keysize is "n", this attack uses only formula_4 encryptions (and formula_5 space) in contrast to the naive attack, which needs formula_1 encryptions (but only formula_7 space).
Key whitening
In cryptography, key whitening is a technique used to increase the security of block ciphers. It consists of steps that combine the data with portions of the key (most commonly using a simple XOR) before the first round and after the last round of encryption. DES-X was the first block cipher that used key whitening.
ESTREAM
eSTREAM is a project to identify "new stream ciphers that might become suitable for widespread adoption", organized by the EU ECRYPT network. It was set up because of the failure of all six stream ciphers submitted to the NESSIE project. The call for primitives was first issued in November 2004. The project was completed in April 2008. The project was divided into separate phases and the project goal was to find algorithms suitable for different kinds of application.
MacGuffin (cipher)
In cryptography, MacGuffin is a block cipher created in 1994 by Bruce Schneier and Matt Blaze at a Fast Software Encryption workshop. It was intended as a catalyst for analysis of a new cipher structure, known as Generalized Unbalanced Feistel Networks (GUFNs).
Schneier and Blaze based MacGuffin on DES, their main change was spliting the DES 64 bits data block into two unequal halves in the Feistel network, 48 bits of the 64-bit data block are fed through the round function, whose output is XORed with the other 16 bits of the data block.
MacGuffin's key schedule is a modified version of the encryption algorithm itself. Since MacGuffin is a Feistel network, decryption is easy; simply run the encryption algorithm in reverse.
The algorithm was experimental, intended to explore the security properties of unbalanced Feistel networks. The cryptanalysis proceeded very quickly, so quickly that the cipher was broken using differential cryptanalysis at the same workshop by Vincent Rijmen and Bart Preneel. They also tried attacking MacGuffin with different S-boxes, taken directly from DES. This version was slightly stronger.
Rijmen and Preneel warn that designing an algorithm to resist only known attacks is generally not a good design principle.
Schneier and Blaze recommended using 32 "rounds", and specified MacGuffin with a 128-bit key.
Feistel cipher
In cryptography, a Feistel cipher is a symmetric structure used in the construction of block ciphers, named after the German IBM cryptographer ; it is also commonly known as a Feistel network. A large set of block ciphers use the scheme, including the Data Encryption Standard
The Feistel structure has the advantage that encryption and decryption operations are very similar, even identical in some cases, requiring only a reversal of the key schedule. Therefore the size of the code or circuitry required to implement such a cipher is nearly halved.
Feistel construction is iterative in nature which makes implementing the cryptosystem in hardware easier.
Feistel networks and similar constructions are product ciphers, and so combine multiple rounds of repeated operations, such as:
Bit shuffling creates the diffusion effect, while substitution is used for confusion.
Many modern symmetric block ciphers use Feistel networks, and the structure and properties of Feistel ciphers have been extensively explored by cryptographers. Specifically, Michael Luby and Charles Rackoff analyzed the Feistel block cipher construction, and proved that if the round function is a cryptographically secure pseudorandom function, with K used as the seed, then 3 rounds is sufficient to make the block cipher a pseudorandom permutation, while 4 rounds is sufficient to make it a "strong" pseudorandom permutation (which means that it remains pseudorandom even to an adversary who gets oracle access to its inverse permutation). Because of this very important result of Luby and Rackoff, Feistel ciphers are sometimes called Luby-Rackoff block ciphers. Further theoretical studies generalized the construction, and defined more precise limits for security.
Let formula_1 be the round function and let
formula_2 be the sub-keys for the rounds formula_3 respectively.
Then the basic operation is as follows:
Split the plaintext block into two equal pieces, (formula_4, formula_5)
For each round formula_6, compute (calculate)
Then the ciphertext is formula_9. (Commonly the two pieces formula_10 and formula_11 are not switched after the last round.)
Decryption of a ciphertext formula_12 is accomplished by computing for formula_13
Then formula_16 is the plaintext again.
One advantage of this model is that the round function formula_1 does not have to be "invertible", and can be very complex.
The diagram illustrates the encryption process. Decryption requires only reversing the order of the subkey formula_18 using the same process; this is the only difference between encryption and decryption:
Unbalanced Feistel ciphers use a modified structure where formula_4 and formula_5 are not of equal lengths. The MacGuffin cipher is an experimental example of such a cipher.
The Feistel construction is also used in cryptographic algorithms other than block ciphers. For example, the Optimal Asymmetric Encryption Padding (OAEP) scheme uses a simple Feistel network to randomize ciphertexts in certain asymmetric-key encryption schemes.
Feistel or modified Feistel:
Blowfish,
Camellia,
CAST-128,
DES,
FEAL,
ICE,
KASUMI,
LOKI97,
Lucifer,
MARS,
MAGENTA,
MISTY1,
RC5,
TEA,
Triple DES,
Twofish,
XTEA,
Generalised Feistel:
CAST-256,
MacGuffin,
RC2,
RC6,
George Wythe
George Wythe (1726 – June 8, 1806), was a lawyer, judge, prominent law professor and "Virginia's foremost classical scholar." Wythe was one of the seven men from Virginia who signed the United States Declaration of Independence.
Wythe served as mayor of Williamsburg, Virginia from 1768 to 1769. In 1779 he was appointed to the newly created Chair of Law at William and Mary, becoming the first law professor in the United States. Wythe's pupils included Thomas Jefferson, Henry Clay, James Monroe, and John Marshall.
Josiah Bartlett
Josiah Bartlett (November 21, 1729– May 19, 1795), was an American physician and statesman, delegate to the Continental Congress for New Hampshire. He signed the Declaration of Independence. He was later Chief Justice of the New Hampshire Superior Court of Judicature and governor of the state.
Carter Braxton
Carter Braxton (September 10, 1736 – October 10, 1797), was a signer of the United States Declaration of Independence and a representative of Virginia.
He was born on Newington Plantation in King and Queen County, Virginia and educated at the William and Mary. He married a wealthy heiress named Judith Robinson at the age nineteen, but she died two years later, leaving him two daughters.
He journeyed to England for two years and returned to the colonies in 1760, marrying again, this time to Elizabeth Corbin, and represented King William County in the Virginia House of Burgesses. He joined the patriot's Committee of Safety in Virginia in 1774 and represented his county in the Virginia Convention.
When Peyton Randolph died in 1775, Braxton was appointed to take his place in the Continental Congress. He served in the Congress from February 1776 until August, when Virginia reduced its delegation to five members. Afterwards he returned to the House of Burgesses, and later served on the State's Executive Council.
Islamic theology
Islamic theology deals with the beliefs of the Islamic faith.
Islamic theology comes from the Qur'an, Hadith, and the story of Muhammad's life ("Sirah Rasul Allah").
Kalam is the Islamic philosophy of seeking theological principles through dialectic. In Arabic, the word means "speech". A scholar of kalam is called a "mutakallim" (Muslim theologian; plural "mutakallimiin").
Eschatology is understood as the last things or ultimate things, and in Muslim theology, eschatology is about the end of this world and what will happen in the next world. Eschatology covers the death of human beings, their souls after their bodily death, the destruction of this world, the resurrection of human souls, the final judgments of human deeds by Allah after the resurrection, and the rewards and punishments for the believers and non-believers. The places for the believers are known as Paradise and for the non-believers as Hell.
Comparative religion in Muslim theology is about the differences and similarities between it and other theologies such as Christian and Jewish as explained in the Qur'an and the Prophetic traditions.
In the history of Muslim theology, there have been theological schools among Muslims with both similarities and differences with each other about their beliefs.
Sunni Muslims hold that there are six articles of belief: belief in Allah, in angels, in divinely revealed scripture] like Qur'an, in prophets, in the "Last Day" or end times, and in predestination.
Shi`ite Muslims hold that there are five articles of belief: the Divine Oneness and Justice, the Prophethood, the Imamate, and eschatology.
In the relationship between humans and their creator, Mu`tazilites emphasize human free will over predestination and God's justice over God's omnipotence. Mu'tazilites also believe in the use of logic to decide the true meanings of the Qur'an. This and the principal of Ijtihad, led to their belief in dynamic Fiqh.
A MacBook is a type of laptop computer made by Apple Inc. It runs macOS and comes with a built in webcam and microphone and a power adapter that is attached by magnets or USB-C. MacBooks are currently available housed in Silver, Space Gray, Gold and Rose Gold aluminium.
Many college students purchase MacBooks to help with their studies and to stay connected with their family and friends.
The first models were released in 2006. It now has the same "unibody" construction as the MacBook Pro's.
The Macbook was introduced by Apple in May 2006. It replaced the iBook and 12 inch PowerBook series of notebooks because Apple was switching all of their CPUs to Intel from Power PC's.
Apple upgrades, or makes the MacBook better, about every six months to two years. This makes them faster and more reliable.
In October 2008, Apple decided to make a MacBook housed in aluminum. It was pretty much the same as the one housed in plastic except that it was a little better and that it was housed in metal. In June 2009, during WWDC (Apple's big yearly gathering), this laptop was renamed the MacBook Pro 13 inch.
In 2011, Apple stopped the production of MacBooks. However, in 2015 Apple released 12-inch MacBook, with a smaller Retina display.
An SMS, or short messaging service is a type of communication used in mobile phones. They are more commonly called 'text messages'. With SMS, someone can send text to another person.
SMS can be slow, as a network gives priority to phone calls, and only carries text messages after calls are handled. There is also a limit of 160 characters that a text message can send. Longer messages than this will be sent as multiple messages, where the sender has to pay for each individual message.
Text messages are often sent between phone users when an actual phone call is not wanted or needed. For example, they may be used in a situation where silence is needed, or to send something private that one person does not want people near them to hear. Message price depends on the phone network of the user. Some mobile phone plans allow for unlimited texting.
International waters
International waters is a body of water that does not belong to any country. This is because it is farther than two hundred miles away from a country.
Alternative hip hop
Alternative hip hop is a form of hip hop music that is very different from gangsta rap, crunk, and snap. A way to explain it would be that if "regular hip hop" was on the middle of a number line, gangsta rap, crunk, and snap would be on one side, and alternative hip hop would be on the other. Even though it is a form of hip hop, fans of alternative hip hop tend to also be fans of horrorcore more than "regular hip hop" or especially R&B.
Alternative hip hop originally came from the United States, and some artists like Gorillaz sprang up from the United Kingdom. Examples of American alternative hip hop artists are Talib Kweli, Mos Def, (and the band they started together, Black Star), Common, Nas, Kanye West, A Tribe Called Quest, Jurassic 5, and Styles of Beyond. It started as a movement-of-sorts from hip hop artists against the "tasteless" hip hop that was popular in the 1990s.
Jason Varitek
Jason Varitek (born April 11, 1972 in Rochester, Michigan) is an American retired baseball player who played in the MLB. Varitek played for the Boston Red Sox up until his retirement in March 2012.
Varitek was called up from Triple A Pawtucket on September 24, 1997, for one game. In 1998, he and catcher Scott Hatteberg were the starting catchers. That season, Varitek played 86 games, while Hatteberg played 76. Varitek had a good spring training in 1999. Because of that, he became the starting catcher.
Varitek had a great season in 1999. Varitek played in 144 games. He hit a .269 batting average, with 20 home runs and 76 RBIs. Varitek went 5–21 with 3 RBI in the 1999 ALDS playing. the Cleveland Indians. He then went 4–20 with 1 RBI in the ALCS playing the New York Yankees.
Süddeutsche Zeitung
The Süddeutsche Zeitung ("South German Newspaper") is the most-read nationwide quality-newspaper in Germany. It is published in Munich. Recently, they are known for leaking offshore bank accounts that led to the Panama Papers and the Paradise Papers leak.
The Süddeutsche Zeitung is a liberal newspaper. The national edition features four sections: Politics, Culture, Economy and Sports. There are also regional editions for Munich and Bavaria featuring local news. There are 6 newspapers a week. It has the second most readers in Germany after the tabloid newspaper Bild-Zeitung. There are about 442,000 papers sold each day, reaching over 1.1 million readers daily.
The Süddeutsche Zeitung was published for the first time on October 6, 1945. It was the first newspaper in Bavaria to get a licence from the U.S. military government after World War II.
Frankfurter Allgemeine Zeitung
The Frankfurter Allgemeine Zeitung is a conserative newspaper in Germany.
The Frankfurter Allgemeine Zeitung is the leading conservative newspaper in Germany.
There are 6 newspapers a week and supplementary the Frankfurter Allgemeine Sonntagszeitung on Sundays.
There are about 360,000 newspapers sold every day.
It is the German newspaper with the widest circulation abroad. It is sold to 148 countries every day.
The first edition of the FAZ published on November 1, 1949. Its founding editor was Erich Welter. Some editors had worked for the Frankfurter Zeitung, which was banned in 1943.
Frankfurter Rundschau
The Frankfurter Rundschau is a nationwide newspaper in Germany.
The <nowiki>"</nowiki>Frankfurter Rundschau is a left-wing liberal newspaper in Germany. Its position is often similar to the positions of the trade unions.
There are 6 newspapers a week.
It has a regional part for Hesse and a local part for Frankfurt am Main, too.
There are about 180,000 newapapers sold daily.
The <nowiki>"Franfurter Rundschau"</nowiki> is the first newspaper in Germany in the tabloid format.
The Frankfurter Rundschau<nowiki>"</nowiki> was the second newspaper starting in Germany after the World War II on the 1st of August 1945.
And it was the first newspaper in the U.S. sector.
The licence was handed over to the first team of editors consisting of Emil Carlebach, Hans Etzkorn, Wilhelm Karl Gerst, Otto Grossmann, Wilhelm Knothe, Paul Rodemann and Arno Rudert.
There were social democrats, political katholics and communists, who had spent years in the resistance and nazi concentration camps or in exile.
Die Zeit
Die Zeit is a nationwide weekly newspaper in Germany.
"Die Zeit" (the title means: "The Time") is read by about 2 million people. It sells about 480.000 copies every week. It is well known for its good articles which are well-written and often detailed. It is read by well-educated people. It is a liberal newspaper.
It includes articles about politics, economics, knowledge, the sciences, art, literature, education, life (style) and travel. It has many advertisements for jobs at universities.
The first copies of "Die Zeit" were published on the 21 February 1946 in Hamburg.
Since that day it has been published in Hamburg every week.
Der Spiegel
Der Spiegel is a weekly political magazine in Germany.
It was set up in 1947 as a copy of "Time magazine". It is now one of Europe's largest weekly magazines.
Der Spiegel is a liberal magazine. It has long, detailed articles.
It has a circulation of more than one million per week. It now has an on-line version, "Spiegel Online".
The first edition of the Spiegel magazine was published in Hanover on 4 January 1947. Later it was published in Hamburg.
Rudolf Augstein was the publisher from the very first issue until his death in 2002.
There was an affair which became known as the "Spiegel affair" in the early 1960s, when Defense Secretary Franz-Josef Strauß arrested writers and publishers of the Spiegel, because he was angry about a critical report on the Germany army (the Bundeswehr).
Many political affairs in Germany were first made known by Der Spiegel, e.g. the Flick affair. "The magazine is renowned for its aggressive, vigorous, and well-written exposes of government malpractice and scandals".
Oliver Wolcott
Oliver Wolcott (December 1, 1726– December 1, 1797), was a signer of the United States Declaration of Independence and also the Articles of Confederation as a representative of Connecticut.