Pseudorandom Function Family
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Pseudorandom Function Family
In cryptography, a pseudorandom function family, abbreviated PRF, is a collection of efficiently-computable functions which emulate a random oracle in the following way: no efficient algorithm can distinguish (with significant advantage) between a function chosen randomly from the PRF family and a random oracle (a function whose outputs are fixed completely at random). Pseudorandom functions are vital tools in the construction of cryptographic primitives, especially secure encryption schemes. Pseudorandom functions are not to be confused with pseudorandom generators (PRGs). The guarantee of a PRG is that a ''single'' output appears random if the input was chosen at random. On the other hand, the guarantee of a PRF is that ''all its outputs'' appear random, regardless of how the corresponding inputs were chosen, as long as the ''function'' was drawn at random from the PRF family. A pseudorandom function family can be constructed from any pseudorandom generator, using, for exampl ...
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Cryptography
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), adversarial behavior. More generally, cryptography is about constructing and analyzing Communication protocol, 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 (confidentiality, data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, Smart card#EMV, chip-based payment cards, digital currencies, password, computer passwords, and military communications. ...
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Advanced Encryption Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant of the Rijndael block cipher developed by two Belgium, Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the Advanced Encryption Standard process, AES selection process. Rijndael is a family of ciphers with different key size, key and Block size (cryptography), block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits. AES has been adopted by the Federal government of the United States, U.S. government. It supersedes the Data Encryption Standard (DES), which was published in 1977. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting ...
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Theory Of Cryptography
A theory is a systematic and rational form of abstract thinking about a phenomenon, or the conclusions derived from such thinking. It involves contemplative and logical reasoning, often supported by processes such as observation, experimentation, and research. Theories can be scientific, falling within the realm of empirical and testable knowledge, or they may belong to non-scientific disciplines, such as philosophy, art, or sociology. In some cases, theories may exist independently of any formal discipline. In modern science, the term "theory" refers to Scientific theory, scientific theories, a well-confirmed type of explanation of nature, made in a way Consistency, consistent with the scientific method, and fulfilling the Scientific theory#Characteristics of theories, criteria required by modern science. Such theories are described in such a way that scientific tests should be able to provide Empirical evidence, empirical support for it, or Empirical evidence, empirical contradi ...
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Pseudorandom Permutation
In cryptography, a pseudorandom permutation (PRP) is a function that cannot be distinguished from a random permutation (that is, a permutation selected at random with uniform probability, from the family of all permutations on the function's domain) with practical effort. Definition Let ''F'' be a mapping \left\^n \times \left\^s \rightarrow \left\^n. ''F'' is a PRP if and only if * For any K \in \left\^s, F_K is a bijection from \left\^n to \left\^n, where F_K(x)=F(x,K). * For any K \in \left\^s, there is an "efficient" algorithm to evaluate F_K(x) for any x \in \left\^n,. * For all probabilistic polynomial-time distinguishers D: \left, Pr\left(D^(1^n) = 1\right) - Pr\left(D^(1^n) = 1\right) \ < \varepsilon(s), where K \in \left\^s is chosen uniformly at random and f_n is chosen uniformly at random from the set of permutations on ''n''-bit strings. A pseudorandom permutation family is a collection of pseudorandom permutations, where a specific p ...
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Identification Friend Or Foe
Identification, friend or foe (IFF) is a combat identification system designed for command and control. It uses a transponder that listens for an ''interrogation'' signal and then sends a ''response'' that identifies the broadcaster. IFF systems usually use radar frequencies, but other electromagnetic frequencies, radio or infrared, may be used. It enables military and civilian air traffic control interrogation systems to identify aircraft, vehicles or forces as friendly, as opposed to neutral or hostile, and to determine their bearing and range from the interrogator. IFF is used by both military and civilian aircraft. IFF was first developed during World War II, with the arrival of radar, and several friendly fire incidents. IFF can only positively identify friendly aircraft or other forces. If an IFF interrogation receives no reply or an invalid reply, the object is not positively identified as foe; friendly forces may not properly reply to IFF for various reasons such as e ...
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ID Number
An identifier is a name that identifies (that is, labels the identity of) either a unique object or a unique ''class'' of objects, where the "object" or class may be an idea, person, physical countable object (or class thereof), or physical noncountable substance (or class thereof). The abbreviation ID often refers to identity, identification (the process of identifying), or an identifier (that is, an instance of identification). An identifier may be a word, number, letter, symbol, or any combination of those. The words, numbers, letters, or symbols may follow an encoding system (wherein letters, digits, words, or symbols ''stand for'' epresentideas or longer names) or they may simply be arbitrary. When an identifier follows an encoding system, it is often referred to as a code or id code. For instance the ISO/IEC 11179 metadata registry standard defines a code as ''system of valid symbols that substitute for longer values'' in contrast to identifiers without symbolic mea ...
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Message Authentication Code
In cryptography, a message authentication code (MAC), sometimes known as an authentication tag, is a short piece of information used for authentication, authenticating and Data integrity, integrity-checking a message. In other words, it is used to confirm that the message came from the stated sender (its authenticity) and has not been changed (its integrity). The MAC value allows verifiers (who also possess a secret key) to detect any changes to the message content. Terminology The term message integrity code (MIC) is frequently substituted for the term ''MAC'', especially in communications to distinguish it from the use of the latter as ''media access control address'' (''MAC address''). However, some authors use MIC to refer to a message digest, which aims only to uniquely but opaquely identify a single message. RFC 4949 recommends avoiding the term ''message integrity code'' (MIC), and instead using ''checksum'', ''error detection code'', ''hash function, hash'', ''keyed hash'' ...
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Dynamic Perfect Hashing
In computer science, dynamic perfect hashing is a programming technique for resolving collisions in a hash table data structure.Fredman, M. L., Komlós, J., and Szemerédi, E. 1984. Storing a Sparse Table with 0(1) Worst Case Access Time. J. ACM 31, 3 (Jun. 1984), 538-544 http://portal.acm.org/citation.cfm?id=1884#Dietzfelbinger, M., Karlin, A., Mehlhorn, K., Meyer auf der Heide, F., Rohnert, H., and Tarjan, R. E. 1994"Dynamic Perfect Hashing: Upper and Lower Bounds". SIAM J. Comput. 23, 4 (Aug. 1994), 738-761. http://portal.acm.org/citation.cfm?id=182370 While more memory-intensive than its hash table counterparts, this technique is useful for situations where fast queries, insertions, and deletions must be made on a large set of elements. Details Static case FKS Scheme The problem of optimal static hashing was first solved in general by Fredman, Komlós and Szemerédi. In their 1984 paper, they detail a two-tiered hash table scheme in which each bucket of the (first-level ...
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Microsoft Edge
Microsoft Edge is a Proprietary Software, proprietary cross-platform software, cross-platform web browser created by Microsoft and based on the Chromium (web browser), Chromium open-source project, superseding Edge Legacy. In Windows 11, Edge is the only browser available from Microsoft. First made available only for Android (operating system), Android and iOS in 2017, in late 2018, Microsoft announced it would completely rebuild Edge as a Chromium (web browser), Chromium-based browser with Blink (browser engine), Blink and V8 (JavaScript engine), V8 engines, which allowed the browser to be ported from Windows 10 to macOS. The new Edge was publicly released in January 2020, and on Xbox as well as Linux in 2021. Edge was also available on Windows 7 and Windows 8, 8/Windows 8.1, 8.1 until early 2023. In February 2023, according to StatCounter, Microsoft Edge became the Usage share of web browsers, third most popular browser in the world, behind Safari (web browser), Safari and ...
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