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Forking Lemma
The forking lemma is any of a number of related lemmas in cryptography research. The lemma states that if an adversary (typically a probabilistic Turing machine), on inputs drawn from some distribution, produces an output that has some property with non-negligible probability, then with non-negligible probability, if the adversary is re-run on new inputs but with the same random tape, its second output will also have the property. This concept was first used by David Pointcheval and Jacques Stern in "Security proofs for signature schemes," published in the proceedings of Eurocrypt 1996.Adam Young and Moti Yung, "Malicious Cryptography: Exposing Cryptovirology", Wiley press, 2004, pp. 344. In their paper, the forking lemma is specified in terms of an adversary that attacks a digital signature scheme instantiated in the random oracle model. They show that if an adversary can forge a signature with non-negligible probability, then there is a non-negligible probability that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemma (mathematics)
In mathematics, informal logic and argument mapping, a lemma (plural lemmas or lemmata) is a generally minor, proven proposition which is used as a stepping stone to a larger result. For that reason, it is also known as a "helping theorem" or an "auxiliary theorem". In many cases, a lemma derives its importance from the theorem it aims to prove; however, a lemma can also turn out to be more important than originally thought. The word "lemma" derives from the Ancient Greek ("anything which is received", such as a gift, profit, or a bribe). Comparison with theorem There is no formal distinction between a lemma and a theorem, only one of intention (see Theorem terminology). However, a lemma can be considered a minor result whose sole purpose is to help prove a more substantial theorem – a step in the direction of proof. Well-known lemmas A good stepping stone can lead to many others. Some powerful results in mathematics are known as lemmas, first named for their originally min ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claus P
Claus (sometimes Clas) is both a given name and a German, Danish, and Dutch surname. Notable people with the name include: Given name *Claus Schenk Graf von Stauffenberg (1907–1944), a German officer who, along with others, attempted to assassinate Hitler in 1944 *Claus von Amsberg, Prince Claus of the Netherlands, Jonkheer van Amsberg (1926–2002) *Claus von Bülow (born 1926), British socialite accused of attempting to murder his wife, Sunny von Bülow *Claus Clausen (other), three people of that name *Claus Bech Jørgensen (born 1976), Danish-born Faroese footballer *Claus Jacob (born 1969), German scientist *Claus Jørgensen (racewalker) (born 1974), Danish race walker *Claus Larsen (other), three people of that name *Claus Lundekvam (born 1973), Norwegian former footballer *Claus Moser, Baron Moser (born 1922), British statistician *Claus Nielsen (born 1964), Danish former football striker *Claus Norreen (born 1970), Danish musician with the band Aqua, and r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ElGamal Signature Scheme
The ElGamal signature scheme is a digital signature scheme which is based on the difficulty of computing discrete logarithms. It was described by Taher Elgamal in 1985. (conference version appeared in CRYPTO'84, pp. 10–18) The ElGamal signature algorithm is rarely used in practice. A variant developed at the NSA and known as the Digital Signature Algorithm is much more widely used. There are several other variants. The ElGamal signature scheme must not be confused with ElGamal encryption which was also invented by Taher Elgamal. Overview The ElGamal signature scheme is a digital signature scheme based on the algebraic properties of modular exponentiation, together with the discrete logarithm problem. The algorithm uses a key pair consisting of a public key and a private key. The private key is used to generate a digital signature for a message, and such a signature can be verified by using the signer's corresponding public key. The digital signature provides message authenticatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fork (software Development)
In software engineering, a project fork happens when developers take a copy of source code from one software package and start independent development on it, creating a distinct and separate piece of software. The term often implies not merely a development branch, but also a split in the developer community; as such, it is a form of schism. Grounds for forking are varying user preferences and stagnated or discontinued development of the original software. Free and open-source software is that which, by definition, may be forked from the original development team without prior permission, and without violating copyright law. However, licensed forks of proprietary software (''e.g.'' Unix) also happen. Etymology The word "fork" has been used to mean "to divide in branches, go separate ways" as early as the 14th century. In the software environment, the word evokes the fork system call, which causes a running process to split itself into two (almost) identical copies that (ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uniform Distribution (discrete)
In probability theory and statistics, the discrete uniform distribution is a symmetric probability distribution wherein a finite number of values are equally likely to be observed; every one of ''n'' values has equal probability 1/''n''. Another way of saying "discrete uniform distribution" would be "a known, finite number of outcomes equally likely to happen". A simple example of the discrete uniform distribution is throwing a fair dice. The possible values are 1, 2, 3, 4, 5, 6, and each time the die is thrown the probability of a given score is 1/6. If two dice are thrown and their values added, the resulting distribution is no longer uniform because not all sums have equal probability. Although it is convenient to describe discrete uniform distributions over integers, such as this, one can also consider discrete uniform distributions over any finite set. For instance, a random permutation is a permutation generated uniformly from the permutations of a given length, and a unif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexandria, Virginia
Alexandria is an independent city (United States), independent city in the northern region of the Commonwealth (U.S. state), Commonwealth of Virginia, United States. It lies on the western bank of the Potomac River approximately south of Downtown, Washington, D.C., downtown Washington, D.C. In 2020, the population was 159,467. The city's estimated population has grown by 1% annually since 2010 on average. Like the rest of Northern Virginia and Central Maryland, modern Alexandria has been influenced by its proximity to the U.S. capital. It is largely populated by professionals working in the United States federal civil service, federal civil service, in the U.S. Military, U.S. military, or for one of the many private companies which contract to Government contractor, provide services to the federal government. One of Alexandria's largest employers is the United States Department of Defense, U.S. Department of Defense. Another is the Institute for Defense Analyses. In 2005, the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Association For Computing Machinery
The Association for Computing Machinery (ACM) is a US-based international learned society for computing. It was founded in 1947 and is the world's largest scientific and educational computing society. The ACM is a non-profit professional membership group, claiming nearly 110,000 student and professional members . Its headquarters are in New York City. The ACM is an umbrella organization for academic and scholarly interests in computer science ( informatics). Its motto is "Advancing Computing as a Science & Profession". History In 1947, a notice was sent to various people: On January 10, 1947, at the Symposium on Large-Scale Digital Calculating Machinery at the Harvard computation Laboratory, Professor Samuel H. Caldwell of Massachusetts Institute of Technology spoke of the need for an association of those interested in computing machinery, and of the need for communication between them. ..After making some inquiries during May and June, we believe there is ample interest to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mihir Bellare
Mihir Bellare is a cryptographer and professor at the University of California San Diego. He has published several seminal papers in the field of cryptography (notably in the area of provable security), many of which were co-written with Phillip Rogaway. Bellare has published a number of papers in the field of Format-Preserving Encryption. His students include Michel Abdalla, Chanathip Namprempre, Tadayoshi Kohno and Anton Mityagin. Bellare is one of the authors of skein. In 2003 Bellare was a recipient of RSA's Sixth Annual Conference Award for outstanding contributions in the field of mathematics for his research in cryptography. In 2013 he became a Fellow of the Association for Computing Machinery. In 2019 he was awarded Levchin Prize for Real-World Cryptography for his outstanding contributions to the design and analysis of real-world cryptosystems, including the development of random oracle model, modes of operation, HMAC, and models for key exchange. Bellare's papers cover ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spain
, image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , image_map = , map_caption = , image_map2 = , capital = Madrid , coordinates = , largest_city = Madrid , languages_type = Official language , languages = Spanish language, Spanish , ethnic_groups = , ethnic_groups_year = , ethnic_groups_ref = , religion = , religion_ref = , religion_year = 2020 , demonym = , government_type = Unitary state, Unitary Parliamentary system, parliamentary constitutional monarchy , leader_title1 = Monarchy of Spain, Monarch , leader_name1 = Felipe VI , leader_title2 = Prime Minister of Spain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saragossa
Zaragoza, also known in English as Saragossa,''Encyclopædia Britannica'"Zaragoza (conventional Saragossa)" is the capital city of the Zaragoza Province and of the autonomous community of Aragon, Spain. It lies by the Ebro river and its tributaries, the Huerva and the Gállego, roughly in the center of both Aragon and the Ebro basin. On 1 January 2021 the population of the municipality of Zaragoza was 675,301, (the fifth most populated in Spain) on a land area of . The population of the metropolitan area was estimated in 2006 at 783,763 inhabitants. The municipality is home to more than 50 percent of the Aragonese population. The city lies at an elevation of about above sea level. Zaragoza hosted Expo 2008 in the summer of 2008, a world's fair on water and sustainable development. It was also a candidate for the European Capital of Culture in 2012. The city is famous for its folklore, local cuisine, and landmarks such as the Basílica del Pilar, La Seo Cathedral and the Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Oracle
In cryptography, a random oracle is an oracle (a theoretical black box) that responds to every ''unique query'' with a (truly) random response chosen uniformly from its output domain. If a query is repeated, it responds the same way every time that query is submitted. Stated differently, a random oracle is a mathematical function chosen uniformly at random, that is, a function mapping each possible query to a (fixed) random response from its output domain. Random oracles as a mathematical abstraction were first used in rigorous cryptographic proofs in the 1993 publication by Mihir Bellare and Phillip Rogaway (1993). They are typically used when the proof cannot be carried out using weaker assumptions on the cryptographic hash function. A system that is proven secure when every hash function is replaced by a random oracle is described as being secure in the random oracle model, as opposed to secure in the standard model of cryptography. Applications Random oracles are typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
