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Key Finding Attacks
Key Finding Attacks are attacks on computer systems that make use of cryptography in which computer memory or non-volatile storage is searched for private cryptographic keys that can be used to decrypt or sign data. The term is generally used in the context of attacks which search memory much more efficiently than simply testing each sequence of bytes to determine if it provides the correct answer. They are often used in combination with cold boot attacks to extract key material from computers. Approaches In their seminal paper on Key Finding attacks, Shamir and van Someren proposed two different approaches to key finding: statistical or entropic key finding and analytical key finding. The former relies on detecting differences in the statistical properties of the data that make up cryptographic keys while the later relies on determining specific byte patterns that must necessarily exist in the target key material and looking for these patterns. Statistical key finding In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 synonymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Compression
In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression reduces bits by identifying and eliminating statistical redundancy. No information is lost in lossless compression. Lossy compression reduces bits by removing unnecessary or less important information. Typically, a device that performs data compression is referred to as an encoder, and one that performs the reversal of the process (decompression) as a decoder. The process of reducing the size of a data file is often referred to as data compression. In the context of data transmission, it is called source coding; encoding done at the source of the data before it is stored or transmitted. Source coding should not be confused with channel coding, for error detection and correction or line coding, the means for mapping data onto a signal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blinding (cryptography)
In cryptography, blinding is a technique by which an agent can provide a service to (i.e., compute a function for) a client in an encoded form without knowing either the real input or the real output. Blinding techniques also have applications to preventing side-channel attacks on encryption devices. More precisely, Alice has an input ''x'' and Oscar has a function ''f''. Alice would like Oscar to compute for her without revealing either ''x'' or ''y'' to him. The reason for her wanting this might be that she doesn't know the function ''f'' or that she does not have the resources to compute it. Alice "blinds" the message by encoding it into some other input ''E''(''x''); the encoding ''E'' must be a bijection on the input space of ''f'', ideally a random permutation. Oscar gives her ''f''(''E''(''x'')), to which she applies a decoding ''D'' to obtain . Not all functions allow for blind computation. At other times, blinding must be applied with care. An example of the latter is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NSAKEY
_NSAKEY was a variable name discovered in Windows NT 4 SP5 in 1999 by Andrew D. Fernandes of Cryptonym Corporation. The variable contained a 1024-bit public key; such keys are used in public-key cryptography for encryption and authentication. Because of the name, however, it was speculated that the key would allow the United States National Security Agency (NSA) to subvert any Windows user's security. Microsoft denied the speculation and said that the key's name came from the fact that NSA was the technical review authority for U.S. cryptography export controls. Overview Microsoft requires all cryptography suites that interoperate with Microsoft Windows to have an RSA digital signature. Since only Microsoft-approved cryptography suites can be shipped with Windows, it is possible to keep export copies of this operating system in compliance with the Export Administration Regulations (EAR), which are enforced by the Bureau of Industry and Security (BIS). It was already known th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nadia Heninger
Nadia Heninger (born 1982) is an American cryptographer, computer security expert, and computational number theorist at the University of California, San Diego. Contributions Heninger is known for her work on freezing powered-down security devices to slow their fading memories and allow their secrets to be recovered via a cold boot attack, for her discovery that weak keys for the RSA cryptosystem are in widespread use by internet routers and other embedded devices, for her research on how failures of forward secrecy in bad implementations of the Diffie–Hellman key exchange may have allowed the National Security Agency to decrypt large amounts of internet traffic via the Logjam (computer security), Logjam vulnerability, and for the DROWN attack, which uses servers supporting old and weak cryptography to decrypt traffic from modern clients to modern servers. Heninger's other research contributions include a variant of the RSA cryptosystem that would be secure against quantum com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Factorization
In mathematics, factorization (or factorisation, see American and British English spelling differences#-ise, -ize (-isation, -ization), English spelling differences) or factoring consists of writing a number or another mathematical object as a product of several ''factors'', usually smaller or simpler objects of the same kind. For example, is a factorization of the integer , and is a factorization of the polynomial . Factorization is not usually considered meaningful within number systems possessing division ring, division, such as the real number, real or complex numbers, since any x can be trivially written as (xy)\times(1/y) whenever y is not zero. However, a meaningful factorization for a rational number or a rational function can be obtained by writing it in lowest terms and separately factoring its numerator and denominator. Factorization was first considered by Greek mathematics, ancient Greek mathematicians in the case of integers. They proved the fundamental theorem o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euler's Totient Function
In number theory, Euler's totient function counts the positive integers up to a given integer that are relatively prime to . It is written using the Greek letter phi as \varphi(n) or \phi(n), and may also be called Euler's phi function. In other words, it is the number of integers in the range for which the greatest common divisor is equal to 1. The integers of this form are sometimes referred to as totatives of . For example, the totatives of are the six numbers 1, 2, 4, 5, 7 and 8. They are all relatively prime to 9, but the other three numbers in this range, 3, 6, and 9 are not, since and . Therefore, . As another example, since for the only integer in the range from 1 to is 1 itself, and . Euler's totient function is a multiplicative function, meaning that if two numbers and are relatively prime, then . This function gives the order of the multiplicative group of integers modulo (the group of units of the ring \Z/n\Z). It is also used for defining the RSA e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RSA (cryptosystem)
RSA (Rivest–Shamir–Adleman) is a public-key cryptography, public-key cryptosystem that is widely used for secure data transmission. It is also one of the oldest. The acronym "RSA" comes from the surnames of Ron Rivest, Adi Shamir and Leonard Adleman, who publicly described the algorithm in 1977. An equivalent system was developed secretly in 1973 at Government Communications Headquarters (GCHQ) (the British signals intelligence agency) by the English mathematician Clifford Cocks. That system was classified information, declassified in 1997. In a public-key cryptosystem, the encryption key is public and distinct from the decryption key, which is kept secret (private). An RSA user creates and publishes a public key based on two large prime numbers, along with an auxiliary value. The prime numbers are kept secret. Messages can be encrypted by anyone, via the public key, but can only be decoded by someone who knows the prime numbers. The security of RSA relies on the pract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Entropy Keys
High may refer to: Science and technology * Height * High (atmospheric), a high-pressure area * High (computability), a quality of a Turing degree, in computability theory * High (tectonics), in geology an area where relative tectonic uplift took or takes place * Substance intoxication, also known by the slang description "being high" * Sugar high, a misconception about the supposed psychological effects of sucrose Music Performers * High (musical group), a 1974–1990 Indian rock group * The High, an English rock band formed in 1989 Albums * ''High'' (The Blue Nile album) or the title song, 2004 * ''High'' (Flotsam and Jetsam album), 1997 * ''High'' (New Model Army album) or the title song, 2007 * ''High'' (Royal Headache album) or the title song, 2015 * ''High'' (EP), by Jarryd James, or the title song, 2016 Songs * "High" (Alison Wonderland song), 2018 * "High" (The Chainsmokers song), 2022 * "High" (The Cure song), 1992 * "High" (David Hallyday song), 1988 * "Hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropy (information Theory)
In information theory, the entropy of a random variable is the average level of "information", "surprise", or "uncertainty" inherent to the variable's possible outcomes. Given a discrete random variable X, which takes values in the alphabet \mathcal and is distributed according to p: \mathcal\to , 1/math>: \Eta(X) := -\sum_ p(x) \log p(x) = \mathbb \log p(X), where \Sigma denotes the sum over the variable's possible values. The choice of base for \log, the logarithm, varies for different applications. Base 2 gives the unit of bits (or " shannons"), while base ''e'' gives "natural units" nat, and base 10 gives units of "dits", "bans", or " hartleys". An equivalent definition of entropy is the expected value of the self-information of a variable. The concept of information entropy was introduced by Claude Shannon in his 1948 paper "A Mathematical Theory of Communication",PDF archived froherePDF archived frohere and is also referred to as Shannon entropy. Shannon's theory defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Memory
In computing, memory is a device or system that is used to store information for immediate use in a computer or related computer hardware and digital electronic devices. The term ''memory'' is often synonymous with the term ''primary storage'' or '' main memory''. An archaic synonym for memory is store. Computer memory operates at a high speed compared to storage that is slower but less expensive and higher in capacity. Besides storing opened programs, computer memory serves as disk cache and write buffer to improve both reading and writing performance. Operating systems borrow RAM capacity for caching so long as not needed by running software. If needed, contents of the computer memory can be transferred to storage; a common way of doing this is through a memory management technique called ''virtual memory''. Modern memory is implemented as semiconductor memory, where data is stored within memory cells built from MOS transistors and other components on an integrated c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generator (mathematics)
In mathematics and physics, the term generator or generating set may refer to any of a number of related concepts. The underlying concept in each case is that of a smaller set of objects, together with a set of operations that can be applied to it, that result in the creation of a larger collection of objects, called the generated set. The larger set is then said to be generated by the smaller set. It is commonly the case that the generating set has a simpler set of properties than the generated set, thus making it easier to discuss and examine. It is usually the case that properties of the generating set are in some way preserved by the act of generation; likewise, the properties of the generated set are often reflected in the generating set. List of generators A list of examples of generating sets follow. * Generating set or spanning set of a vector space: a set that spans the vector space * Generating set of a group: A subset of a group that is not contained in any subgro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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