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Subliminal Channels
In cryptography, subliminal channels are covert channels that can be used to communicate secretly in normal looking communication over an insecure channel.Gustavus J. Simmons. The Prisoners Problem and the Subliminal Channel'. In Advances in Cryptology – CRYPTO ’83, pages 51–67, New York, 1984. Lecture Notes in Computer Science, ed. D. Chaum. Subliminal channels in digital signature crypto systems were found in 1984 by Gustavus Simmons. Simmons describes how the "Prisoners' Problem" can be solved through parameter substitution in digital signature algorithms.Gustavus J. Simmons. The subliminal channel and digital signatures'. In Proc. of the EUROCRYPT 84 workshop on Advances in cryptology: theory and application of cryptographic techniques, pages 364–378, New York, NY, USA, 1985. Springer-Verlag New York, Inc. (Note that Simmons' Prisoners' Problem is not the same as the Prisoner's Dilemma.) Signature algorithms like ElGamal and DSA have parameters which must be set wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covert Channels
In computer security, a covert channel is a type of attack that creates a capability to transfer information objects between processes that are not supposed to be allowed to communicate by the computer security policy. The term, originated in 1973 by Butler Lampson, is defined as channels "not intended for information transfer at all, such as the service program's effect on system load," to distinguish it from ''legitimate'' channels that are subjected to access controls by COMPUSEC. Characteristics A covert channel is so called because it is hidden from the access control mechanisms of secure operating systems since it does not use the legitimate data transfer mechanisms of the computer system (typically, read and write), and therefore cannot be detected or controlled by the security mechanisms that underlie secure operating systems. Covert channels are exceedingly hard to install in real systems, and can often be detected by monitoring system performance. In addition, they su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insecure Channel
In cryptography, a secure channel is a means of data transmission that is resistant to overhearing and tampering. A confidential channel is a means of data transmission that is resistant to overhearing, or eavesdropping (e.g., reading the content), but not necessarily resistant to tampering (i.e., manipulating the content). An authentic channel is a means of data transmission that is resistant to tampering but not necessarily resistant to overhearing. In contrast to a secure channel, an insecure channel is unencrypted and may be subject to eavesdropping and tampering. Secure communications are possible over an insecure channel if the content to be communicated is encrypted prior to transmission. Secure channels in the real world There are no perfectly secure channels in the real world. There are, at best, only ways to make insecure channels (e.g., couriers, homing pigeons, diplomatic bags, etc.) less insecure: padlocks (between courier wrists and a briefcase), loyalty tests ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created by a known sender (authenticity), and that the message was not altered in transit (integrity). Digital signatures are a standard element of most cryptographic protocol suites, and are commonly used for software distribution, financial transactions, contract management software, and in other cases where it is important to detect forgery or tampering. Digital signatures are often used to implement electronic signatures, which includes any electronic data that carries the intent of a signature, but not all electronic signatures use digital signatures. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gustavus Simmons
Gustavus J. Simmons (born 1930) is a retired cryptographer and former manager of the applied mathematics Department and Senior Fellow at Sandia National Laboratories. He worked primarily with authentication theory, developing cryptographic techniques for solving problems of mutual distrust and in devising protocols whose function could be trusted, even though some of the inputs or participants cannot be. Simmons was born in West Virginia and was named after his grandfather, a prohibition officer who was gunned down three years before Gustavus was born. He began his post-secondary education at Deep Springs College, and received his Ph.D in mathematics from the University of New Mexico, Albuquerque. Simmons has published over 170 papers, many of which are devoted to asymmetric encryption techniques. His technical contributions include the development of subliminal channels which make it possible to conceal covert communications in digital signatures and the mathematical formulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prisoner's Dilemma
The Prisoner's Dilemma is an example of a game analyzed in game theory. It is also a thought experiment that challenges two completely rational agents to a dilemma: cooperate with their partner for mutual reward, or betray their partner ("defect") for individual reward. This dilemma was originally framed by Merrill Flood and Melvin Dresher while working at RAND in 1950. Albert W. Tucker appropriated the game and formalized it by structuring the rewards in terms of prison sentences and named it "prisoner's dilemma". William Poundstone in his 1993 book ''Prisoner's Dilemma'' writes the following version:Two members of a criminal gang are arrested and imprisoned. Each prisoner is in solitary confinement with no means of speaking to or exchanging messages with the other. The police admit they don't have enough evidence to convict the pair on the principal charge. They plan to sentence both to two years in prison on a lesser charge. Simultaneously, the police offer each prisoner a ... [...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] |
Digital Signature Algorithm
The Digital Signature Algorithm (DSA) is a Public-key cryptography, public-key cryptosystem and Federal Information Processing Standards, Federal Information Processing Standard for digital signatures, based on the mathematical concept of modular exponentiation and the Discrete logarithm, discrete logarithm problem. DSA is a variant of the Schnorr signature, Schnorr and ElGamal signature scheme, ElGamal signature schemes. The National Institute of Standards and Technology (NIST) proposed DSA for use in their Digital Signature Standard (DSS) in 1991, and adopted it as FIPS 186 in 1994. Four revisions to the initial specification have been released. The newest specification isFIPS 186-4 from July 2013. DSA is patented but NIST has made this patent available worldwide royalty-free. A draft version of the specificatioFIPS 186-5indicates DSA will no longer be approved for digital signature generation, but may be used to verify signatures generated prior to the implementation date of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impersonation
An impersonator is someone who imitates or copies the behavior or actions of another. There are many reasons for impersonating someone: *Entertainment: An entertainer impersonates a celebrity, generally for entertainment, and makes fun of their personal lives, recent scandals and known behavior patterns. Especially popular objects of impersonation are Elvis Presley (''see Elvis impersonator''), Michael Jackson (''see Michael Jackson impersonator'') and Madonna (see ''Madonna impersonator''). Entertainers who impersonate multiple celebrities as part of their act, can be sorted into impressionists and celebrity impersonators. Male drag queens have traditionally been called "female impersonators", although this terminology is now considered outdated. Minstrel shows were a popular form of theater in the United States in which white people impersonated black people by wearing blackface makeup and imitating Southern black speech and music. *Crime: As part of a criminal act such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centrum Wiskunde & Informatica
The (abbr. CWI; English: "National Research Institute for Mathematics and Computer Science") is a research centre in the field of mathematics and theoretical computer science. It is part of the institutes organization of the Dutch Research Council (NWO) and is located at the Amsterdam Science Park. This institute is famous as the creation site of the programming language Python. It was a founding member of the European Research Consortium for Informatics and Mathematics (ERCIM). Early history The institute was founded in 1946 by Johannes van der Corput, David van Dantzig, Jurjen Koksma, Hendrik Anthony Kramers, Marcel Minnaert and Jan Arnoldus Schouten. It was originally called ''Mathematical Centre'' (in Dutch: ''Mathematisch Centrum''). One early mission was to develop mathematical prediction models to assist large Dutch engineering projects, such as the Delta Works. During this early period, the Mathematics Institute also helped with designing the wings of the Fokker F27 F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amsterdam
Amsterdam ( , , , lit. ''The Dam on the River Amstel'') is the Capital of the Netherlands, capital and Municipalities of the Netherlands, most populous city of the Netherlands, with The Hague being the seat of government. It has a population of 907,976 within the city proper, 1,558,755 in the City Region of Amsterdam, urban area and 2,480,394 in the Amsterdam metropolitan area, metropolitan area. Located in the Provinces of the Netherlands, Dutch province of North Holland, Amsterdam is colloquially referred to as the "Venice of the North", for its large number of canals, now designated a World Heritage Site, UNESCO World Heritage Site. Amsterdam was founded at the mouth of the Amstel River that was dammed to control flooding; the city's name derives from the Amstel dam. Originally a small fishing village in the late 12th century, Amsterdam became a major world port during the Dutch Golden Age of the 17th century, when the Netherlands was an economic powerhouse. Amsterdam is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero-knowledge Proof
In cryptography, a zero-knowledge proof or zero-knowledge protocol is a method by which one party (the prover) can prove to another party (the verifier) that a given statement is true while the prover avoids conveying any additional information apart from the fact that the statement is indeed true. The essence of zero-knowledge proofs is that it is trivial to prove that one possesses knowledge of certain information by simply revealing it; the challenge is to prove such possession without revealing the information itself or any additional information. If proving a statement requires that the prover possess some secret information, then the verifier will not be able to prove the statement to anyone else without possessing the secret information. The statement being proved must include the assertion that the prover has such knowledge, but without including or transmitting the knowledge itself in the assertion. Otherwise, the statement would not be proved in zero-knowledge because it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutual Assured Destruction
Mutual assured destruction (MAD) is a doctrine of military strategy and national security policy which posits that a full-scale use of nuclear weapons by an attacker on a nuclear-armed defender with second-strike capabilities would cause the complete annihilation of both the attacker and the defender. It is based on the theory of rational deterrence, which holds that the threat of using strong weapons against the enemy prevents the enemy's use of those same weapons. The strategy is a form of Nash equilibrium in which, once armed, neither side has any incentive to initiate a conflict or to disarm. The term "mutual assured destruction", commonly abbreviated "MAD", was coined by Donald Brennan, a strategist working in Herman Kahn's Hudson Institute in 1962. However, Brennan came up with this acronym ironically, spelling out the English word " mad" to argue that holding weapons capable of destroying society was irrational. Theory Under MAD, each side has enough nuclear weapon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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