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Differential Equations Of Addition
In cryptography, differential equations of addition (DEA) are one of the most basic equations related to differential cryptanalysis that mix additions over two different groups (e.g. addition modulo 232 and addition over GF(2)) and where input and output differences are expressed as XORs. Examples Differential equations of addition (DEA) are of the following form: (x+y)\oplus((x\oplus a)+(y\oplus b))=c where x and y are n-bit unknown variables and a, b and c are known variables. The symbols + and \oplus denote ''addition modulo'' 2^n and ''bitwise exclusive-or'' respectively. The above equation is denoted by (a, b, c). Let a set S=\ for integer i denote a system of k(n) DEA where k(n) is a polynomial in n. It has been proved that the satisfiability of an arbitrary set of DEA is in the complexity class P when a brute force search requires an exponential time. In 2013, some properties of a special form of DEA were reported by Chengqing Li et al., where a=0 and y is assume ...
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Cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), 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 (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synony ...
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Differential Cryptanalysis
Differential cryptanalysis is a general form of cryptanalysis applicable primarily to block ciphers, but also to stream ciphers and cryptographic hash functions. In the broadest sense, it is the study of how differences in information input can affect the resultant difference at the output. In the case of a block cipher, it refers to a set of techniques for tracing differences through the network of transformation, discovering where the cipher exhibits non-random behavior, and exploiting such properties to recover the secret key (cryptography key). History The discovery of differential cryptanalysis is generally attributed to Eli Biham and Adi Shamir in the late 1980s, who published a number of attacks against various block ciphers and hash functions, including a theoretical weakness in the Data Encryption Standard (DES). It was noted by Biham and Shamir that DES was surprisingly resistant to differential cryptanalysis but small modifications to the algorithm would make it much m ...
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Complexity Class P
In computational complexity theory, P, also known as PTIME or DTIME(''n''O(1)), is a fundamental complexity class. It contains all decision problems that can be solved by a deterministic Turing machine using a polynomial amount of computation time, or polynomial time. Cobham's thesis holds that P is the class of computational problems that are "efficiently solvable" or " tractable". This is inexact: in practice, some problems not known to be in P have practical solutions, and some that are in P do not, but this is a useful rule of thumb. Definition A language ''L'' is in P if and only if there exists a deterministic Turing machine ''M'', such that * ''M'' runs for polynomial time on all inputs * For all ''x'' in ''L'', ''M'' outputs 1 * For all ''x'' not in ''L'', ''M'' outputs 0 P can also be viewed as a uniform family of boolean circuits. A language ''L'' is in P if and only if there exists a polynomial-time uniform family of boolean circuits \, such that * For all n \in \ ...
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Exponential Time
In computer science, the time complexity is the computational complexity that describes the amount of computer time it takes to run an algorithm. Time complexity is commonly estimated by counting the number of elementary operations performed by the algorithm, supposing that each elementary operation takes a fixed amount of time to perform. Thus, the amount of time taken and the number of elementary operations performed by the algorithm are taken to be related by a constant factor. Since an algorithm's running time may vary among different inputs of the same size, one commonly considers the worst-case time complexity, which is the maximum amount of time required for inputs of a given size. Less common, and usually specified explicitly, is the average-case complexity, which is the average of the time taken on inputs of a given size (this makes sense because there are only a finite number of possible inputs of a given size). In both cases, the time complexity is generally express ...
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Souradyuti Paul
Souradyuti Paul (born 1976) is an Indian cryptologist. Formerly a member of COSIC, he is currently working as an associate professor at Indian Institute of Technology Bhilai and a Guest Researcher for the National Institute of Standards and Technology in the United States. He participated in cryptanalysis of RC4, Helix and Py family of ciphers among others. He has co-designed the following ciphers * RC4A * RCR-32, RCR-64. He also contributed to the design of a hash function iteration mode of operation Fast-widepipe.Mridul Nandi and Souradyuti Paul. Speeding Up the Widepipe: Secure and Fast Hashing. In Guang Gong and Kishan Gupta, editor, Indocrypt 2010, Springer, 2010. While working at NIST Dr. Paul has worked towards the development of US government secure hash standard SHA-3 being selected through a public competition. References External links Souradyuti Paul's homepage at the Catholic University of LeuvenSouradyuti Paul's weblog addressing computer security rel ...
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Bart Preneel
Bart Preneel (born 15 October 1963 in Leuven, Belgium) is a Flemish cryptographer and cryptanalyst. He is a professor at Katholieke Universiteit Leuven, in the COSIC group. He was the president of the International Association for Cryptologic Research in 2008-2013 and project manager of ECRYPT. Education In 1987, Preneel received an electrical engineering degree in applied science from the Katholieke Universiteit, Leuven. In 1993, Preneel received a PhD from the Katholieke Universiteit Leuven. His dissertation in computer science, entitled ''Analysis and Design of Cryptographic Hash Functions'', was advised by Joos (Joseph) P. L. Vandewalle and René J. M. Govaerts. Career Along with Shoji Miyaguchi, he independently invented the Miyaguchi–Preneel scheme, a complex structure used in the hash function Whirlpool. He is one of the authors of the RIPEMD-160 hash function. He was also a co-inventor of the stream cipher MUGI which would later become a Japanese standar ...
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Fast Software Encryption
Fast or FAST may refer to: * Fast (noun), high speed or velocity * Fast (noun, verb), to practice fasting, abstaining from food and/or water for a certain period of time Acronyms and coded Computing and software * ''Faceted Application of Subject Terminology'', a thesaurus of subject headings * Facilitated Application Specification Techniques, a team-oriented approach for requirement gathering * FAST protocol, an adaptation of the FIX protocol, optimized for streaming * FAST TCP, a TCP congestion avoidance algorithm * FAST and later as Fast Search & Transfer, a Norwegian company focusing on data search technologies * Fatigue Avoidance Scheduling Tool, software to develop work schedules * Features from accelerated segment test, computer vision method for corner detection * Federation Against Software Theft, a UK organization that pursues those who illegally distribute software * Feedback arc set in Tournaments, a computational problem in graph theory * USENIX Conference on Fil ...
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Cryptographic Attacks
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), 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 (data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous wi ...
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Theory Of Cryptography
A theory is a rational type of abstract thinking about a phenomenon, or the results of such thinking. The process of contemplative and rational thinking is often associated with such processes as observational study or research. Theories may be scientific, belong to a non-scientific discipline, or no discipline at all. Depending on the context, a theory's assertions might, for example, include generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings. In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with the scientific method, and fulfilling the criteria required by modern science. Such theories are described in such a way that scientific tests should be able to provide empirical support for it, or empirical contradiction ("falsify") of it. Scientific theories are the most reliable, rigorous, and compreh ...
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