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Universal Composability
The framework of universal composability (UC) is a general-purpose model for the analysis of cryptographic protocols. It guarantees very strong security properties. Protocols remain secure even if arbitrarily composed with other instances of the same or other protocols. Security is defined in the sense of protocol emulation. Intuitively, a protocol is said to emulate another one, if no environment (observer) can distinguish the executions. Literally, the protocol may simulate the other protocol (without having access to the code). The notion of security is derived by implication. Assume a protocol P_1 is secure per definition. If another protocol P_2 emulates protocol P_1 such that no environment tells apart the emulation from the execution of the protocol, then the emulated protocol P_2 is as secure as protocol P_1. Ideal functionality An ideal functionality is a protocol in which a trusted party that can communicate over perfectly secure channels with all protocol participants c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocol (computing)
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both. Communicating systems use well-defined formats for exchanging various messages. Each message has an exact meaning intended to elicit a response from a range of possible responses pre-determined for that particular situation. The specified behavior is typically independent of how it is to be implemented. Communication protocols have to be agreed upon by the parties involved. To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: ''protocols ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Communication
Synchronous serial communication describes a serial communication protocol in which "data is sent in a continuous stream at constant rate." Synchronous communication requires that the clocks in the transmitting and receiving devices are ''synchronized'' – running at the same rate – so the receiver can sample the signal at the same time intervals used by the transmitter. No start or stop bits are required. For this reason "synchronous communication permits more information to be passed over a circuit per unit time" than asynchronous serial communication. Over time the transmitting and receiving clocks will tend to drift apart, requiring ''resynchronization''. Byte-oriented protocols Early synchronous protocols were byte-oriented protocols, where synchronization was maintained by transmitting a sequence of synchronous idle characters when the line was not actively transmitting data or transparently within a long transmission block. A certain number of idles were s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstraction
Abstraction in its main sense is a conceptual process wherein general rules and concepts are derived from the usage and classification of specific examples, literal ("real" or " concrete") signifiers, first principles, or other methods. "An abstraction" is the outcome of this process—a concept that acts as a common noun for all subordinate concepts and connects any related concepts as a ''group'', ''field'', or ''category''.Suzanne K. Langer (1953), ''Feeling and Form: a theory of art developed from Philosophy in a New Key'' p. 90: " Sculptural form is a powerful abstraction from actual objects and the three-dimensional space which we construe ... through touch and sight." Conceptual abstractions may be formed by filtering the information content of a concept or an observable phenomenon, selecting only those aspects which are relevant for a particular purpose. For example, abstracting a leather soccer ball to the more general idea of a ball selects only the information on ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ran Canetti
Ran Canetti (Hebrew: רן קנטי) is a professor of Computer Science at Boston University. and the director of the Check Point Institute for Information Security and of the Center for Reliable Information System and Cyber Security. He is also associate editor of the Journal of Cryptology and Information and Computation. His main areas of research span cryptography and information security, with an emphasis on the design, analysis and use of cryptographic protocols. Biography Born in 1962 in Tel Aviv, Israel, Canetti obtained his BA in Computer Science in 1989, his BA in Physics in 1990, and his M.Sc in Computer Science in 1991, all from the Technion, Haifa. He received his PhD in 1995 from the Weizmann Institute, Rehovot under the supervision of Prof. Oded Goldreich. He then completed his post-doctoral training at the Lab of Computer Science, at the Massachusetts Institute of Technology (MIT) in 1996 under the supervision of Prof. Shafi Goldwasser. He then joined IBM� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victor Shoup
Victor Shoup is a computer scientist and mathematician. He obtained a PhD in computer science from the University of Wisconsin–Madison in 1989, and he did his undergraduate work at the University of Wisconsin-Eau Claire. He is a professor at the Courant Institute of Mathematical Sciences at New York University, focusing on algorithm and cryptography courses. He is currently a Principal Research Scientist at DFINITY and has held positions at AT&T Bell Labs, the University of Toronto, Saarland University, and the IBM Zurich Research Laboratory. Shoup's main research interests and contributions are computer algorithms relating to number theory, algebra, and cryptography. His contributions to these fields include: * The Cramer–Shoup cryptosystem asymmetric encryption algorithm bears his name. * His freely available (under the terms of the GNU GPL) C++ library of number theory algorithms, NTL, is widely used and well regarded for its high performance. * He is the author of a wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Certification Authority
In cryptography, a certificate authority or certification authority (CA) is an entity that stores, signs, and issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or on assertions made about the private key that corresponds to the certified public key. A CA acts as a trusted third party—trusted both by the subject (owner) of the certificate and by the party relying upon the certificate. The format of these certificates is specified by the X.509 or EMV standard. One particularly common use for certificate authorities is to sign certificates used in HTTPS, the secure browsing protocol for the World Wide Web. Another common use is in issuing identity cards by national governments for use in electronically signing documents. Overview Trusted certificates can be used to create secure connections to a server via the Internet. A certificate i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Reference String Model
Common may refer to: Places * Common, a townland in County Tyrone, Northern Ireland * Boston Common, a central public park in Boston, Massachusetts * Cambridge Common, common land area in Cambridge, Massachusetts * Clapham Common, originally common land, now a park in London, UK * Common Moss, a townland in County Tyrone, Northern Ireland * Lexington Common, a common land area in Lexington, Massachusetts * Salem Common Historic District, a common land area in Salem, Massachusetts People * Common (rapper) (born 1972), American hip hop artist, actor, and poet * Andrew Ainslie Common (born 1841), English amateur astronomer * Andrew Common (born 1889), British shipping director * John Common, American songwriter, musician and singer * Thomas Common (born 1850), Scottish translator and literary critic Arts, entertainment, and media * ''Common'' (film), a 2014 BBC One film, written by Jimmy McGovern, on the UK's Joint Enterprise Law * Dol Common, a character in ''The Alchemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Model (cryptography)
In cryptography the standard model is the model of computation in which the adversary is only limited by the amount of time and computational power available. Other names used are bare model and plain model. Cryptographic schemes are usually based on complexity assumptions, which state that some problems, such as factorization, cannot be solved in polynomial time. Schemes that can be proven secure using only complexity assumptions are said to be secure in the standard model. Security proofs are notoriously difficult to achieve in the standard model, so in many proofs, cryptographic primitives are replaced by idealized versions. The most common example of this technique, known as the random oracle model, involves replacing a cryptographic hash function with a genuinely random function. Another example is the generic group model, where the adversary is given access to a randomly chosen encoding of a group, instead of the finite field or elliptic curve groups used in practice. Oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bit Commitment
A commitment scheme is a cryptographic primitive that allows one to commit to a chosen value (or chosen statement) while keeping it hidden to others, with the ability to reveal the committed value later.Oded Goldreich (2001). Foundations of Cryptography: Volume 1, Basic Tools,draft availablefrom author's site). Cambridge University Press. . (see also http://www.wisdom.weizmann.ac.il/~oded/foc-book.html) Commitment schemes are designed so that a party cannot change the value or statement after they have committed to it: that is, commitment schemes are ''binding''. Commitment schemes have important applications in a number of cryptographic protocols including secure coin flipping, zero-knowledge proofs, and secure computation. A way to visualize a commitment scheme is to think of a sender as putting a message in a locked box, and giving the box to a receiver. The message in the box is hidden from the receiver, who cannot open the lock themselves. Since the receiver has the box, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Identifiers
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, 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 meaning. Id ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mobile Device
A mobile device (or handheld computer) is a computer small enough to hold and operate in the hand. Mobile devices typically have a flat LCD or OLED screen, a touchscreen interface, and digital or physical buttons. They may also have a physical keyboard. Many such devices can connect to the Internet and connect with other devices such as car entertainment systems or headsets via Wi-Fi, Bluetooth, cellular networks or near field communication (NFC). Integrated cameras, the ability to place and receive voice and video telephone calls, video games, and Global Positioning System (GPS) capabilities are common. Power is typically provided by a lithium-ion battery. Mobile devices may run mobile operating systems that allow third-party applications to be installed and run. Early smartphones were joined in the late 2000s by larger tablets. Input and output is usually via a touch-screen interface. Phones/tablets and personal digital assistants may provide much of the functionality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
