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Cryptographic Protocol
A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods, often as sequences of cryptographic primitives. A protocol describes how the algorithms should be used and includes details about data structures and representations, at which point it can be used to implement multiple, interoperable versions of a program. Cryptographic protocols are widely used for secure application-level data transport. A cryptographic protocol usually incorporates at least some of these aspects: * Key agreement or establishment * Entity authentication * Symmetric encryption and message authentication material construction * Secured application-level data transport * Non-repudiation methods * Secret sharing methods * Secure multi-party computation For example, Transport Layer Security (TLS) is a cryptographic protocol that is used to secure web (HTTPS) connections. It has an entit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communications Protocol
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 ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Signature
In cryptography a blind signature, as introduced by David Chaum, is a form of digital signature in which the content of a message is disguised ( blinded) before it is signed. The resulting blind signature can be publicly verified against the original, unblinded message in the manner of a regular digital signature. Blind signatures are typically employed in privacy-related protocols where the signer and message author are different parties. Examples include cryptographic election systems and digital cash schemes. An often-used analogy to the cryptographic blind signature is the physical act of a voter enclosing a completed anonymous ballot in a special carbon paper lined envelope that has the voter's credentials pre-printed on the outside. An official verifies the credentials and signs the envelope, thereby transferring his signature to the ballot inside via the carbon paper. Once signed, the package is given back to the voter, who transfers the now signed ballot to a new unmarked no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolev–Yao Model
The Dolev–Yao model, named after its authors Danny Dolev and Andrew Yao, is a formal model used to prove properties of interactive cryptographic protocols. The network The network is represented by a set of abstract machines that can exchange messages. These messages consist of formal terms. These terms reveal some of the internal structure of the messages, but some parts will hopefully remain opaque to the adversary. The adversary The adversary in this model can overhear, intercept, and synthesize any message and is only limited by the constraints of the cryptographic methods used. In other words: "the attacker carries the message." This omnipotence has been very difficult to model, and many threat models simplify it, as has been done for the attacker in ubiquitous computing. The algebraic model Cryptographic primitives are modeled by abstract operators. For example, asymmetric encryption for a user x is represented by the encryption function E_x and the decryption funct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burrows–Abadi–Needham Logic
Burrows–Abadi–Needham logic (also known as the BAN logic) is a set of rules for defining and analyzing information exchange protocols. Specifically, BAN logic helps its users determine whether exchanged information is trustworthy, secured against eavesdropping, or both. BAN logic starts with the assumption that all information exchanges happen on media vulnerable to tampering and public monitoring. This has evolved into the popular security mantra, "Don't trust the network." A typical BAN logic sequence includes three steps: # Verification of message origin # Verification of message freshness # Verification of the origin's trustworthiness. BAN logic uses postulates and definitions – like all axiomatic systems – to analyze authentication protocols. Use of the BAN logic often accompanies a security protocol notation formulation of a protocol and is sometimes given in papers. Language type BAN logic, and logics in the same family, are decidable: there exists an algorithm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formal Verification
In the context of hardware and software systems, formal verification is the act of proving or disproving the correctness of intended algorithms underlying a system with respect to a certain formal specification or property, using formal methods of mathematics. Formal verification can be helpful in proving the correctness of systems such as: cryptographic protocols, combinational circuits, digital circuits with internal memory, and software expressed as source code. The verification of these systems is done by providing a formal proof on an abstract mathematical model of the system, the correspondence between the mathematical model and the nature of the system being otherwise known by construction. Examples of mathematical objects often used to model systems are: finite-state machines, labelled transition systems, Petri nets, vector addition systems, timed automata, hybrid automata, process algebra, formal semantics of programming languages such as operational semantics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anonymous Re-mailer
Anonymous may refer to: * Anonymity, the state of an individual's identity, or personally identifiable information, being publicly unknown ** Anonymous work, a work of art or literature that has an unnamed or unknown creator or author * Anonymity (social choice), a property of a voting rule, saying that it does not discriminate apriori between voters Organizations * Anonymous (hacker group), the collective name of loosely affiliated individuals who participate in hacktivism Film and television * "Anonymous" (''Australian Playhouse''), an Australian television play * ''Anonymous'' (2011 film), a 2011 film * ''Anonymous'' (TV series), a 2006 Irish television show * "Anonymous" (''CSI''), a 2000 episode of ''CSI: Crime Scene Investigation'' * "Anonymous" (''NCIS: Los Angeles''), a 2010 episode of ''NCIS: Los Angeles'' Music * Anonymous (band), an Andorran band * ''Anonymous'' (Blackbear album) (2019) * ''Anonymous'' (Stray from the Path album) (2013) * ''Anony ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deniable Encryption
In cryptography and steganography, plausibly deniable encryption describes encryption techniques where the existence of an encrypted file or message is deniable in the sense that an adversary cannot prove that the plaintext data exists. The users may convincingly deny that a given piece of data is encrypted, or that they are able to decrypt a given piece of encrypted data, or that some specific encrypted data exists. Such denials may or may not be genuine. For example, it may be impossible to prove that the data is encrypted without the cooperation of the users. If the data is encrypted, the users genuinely may not be able to decrypt it. Deniable encryption serves to undermine an attacker's confidence either that data is encrypted, or that the person in possession of it can decrypt it and provide the associated plaintext. Function Deniable encryption makes it impossible to prove the existence of the plaintext message without the proper decryption key. This may be done by allowing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undeniable Signature
An undeniable signature is a digital signature scheme which allows the signer to be selective to whom they allow to verify signatures. The scheme adds explicit signature repudiation, preventing a signer later refusing to verify a signature by omission; a situation that would devalue the signature in the eyes of the verifier. It was invented by David Chaum and Hans van Antwerpen in 1989. Overview In this scheme, a signer possessing a private key can publish a signature of a message. However, the signature reveals nothing to a recipient/verifier of the message and signature without taking part in either of two interactive protocols: * Confirmation protocol, which confirms that a candidate is a valid signature of the message issued by the signer, identified by the public key. * Disavowal protocol, which confirms that a candidate is not a valid signature of the message issued by the signer. The motivation for the scheme is to allow the signer to choose to whom signatures are verified. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
E-voting
Electronic voting (also known as e-voting) is voting that uses electronic means to either aid or take care of casting and counting ballots. Depending on the particular implementation, e-voting may use standalone ''electronic voting machines'' (also called EVM) or computers connected to the Internet (online voting). It may encompass a range of Internet services, from basic transmission of tabulated results to full-function online voting through common connectable household devices. The degree of automation may be limited to marking a paper ballot, or may be a comprehensive system of vote input, vote recording, data encryption and transmission to servers, and consolidation and tabulation of election results. A worthy e-voting system must perform most of these tasks while complying with a set of standards established by regulatory bodies, and must also be capable to deal successfully with strong requirements associated with security, accuracy, integrity, swiftness, privacy, audita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
End-to-end Auditable Voting Systems
End-to-end auditable or end-to-end voter verifiable (E2E) systems are voting systems with stringent integrity properties and strong tamper resistance. E2E systems often employ cryptographic methods to craft receipts that allow voters to verify that their votes were counted as cast, without revealing which candidates were voted for. As such, these systems are sometimes referred to as receipt-based systems. Overview Electronic voting systems arrive at their final vote totals by a series of steps: # each voter has an original intent, # voters express their intent on ballots (whether interactively, as on the transient display of a DRE voting machine, or durable, as in systems with voter verifiable paper trails), # the ballots are interpreted, to generate electronic cast vote records, # cast vote records are tallied, generating totals # where counting is conducted locally, for example, at the precinct or county level, the results from each local level are combined to produce the fin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secure Multiparty Computation
Secure multi-party computation (also known as secure computation, multi-party computation (MPC) or privacy-preserving computation) is a subfield of cryptography with the goal of creating methods for parties to jointly compute a function over their inputs while keeping those inputs private. Unlike traditional cryptographic tasks, where cryptography assures security and integrity of communication or storage and the adversary is outside the system of participants (an eavesdropper on the sender and receiver), the cryptography in this model protects participants' privacy from each other. The foundation for secure multi-party computation started in the late 1970s with the work on mental poker, cryptographic work that simulates game playing/computational tasks over distances without requiring a trusted third party. Note that traditionally, cryptography was about concealing content, while this new type of computation and protocol is about concealing partial information about data while comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
