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Wide Mouth Frog
The Wide-Mouth Frog protocol is a computer network authentication protocol designed for use on insecure networks (the Internet for example). It allows individuals communicating over a network to prove their identity to each other while also preventing eavesdropping or replay attacks, and provides for detection of modification and the prevention of unauthorized reading. This can be proven using Degano. The protocol was first described under the name "The Wide-mouthed-frog Protocol" in the paper "A Logic of Authentication" (1990), which introduced Burrows–Abadi–Needham logic, and in which it was an "unpublished protocol ... proposed by" coauthor Michael Burrows. Burrows, Abadi, and Needham"A Logic of Authentication" ''ACM Transactions on Computer Systems'' 8 (1990), pp. 18–36. The paper gives no rationale for the protocol's whimsical name. The protocol can be specified as follows in security protocol notation: [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies, based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies. The nodes of a computer network can include personal computers, servers, networking hardware, or other specialised or general-purpose hosts. They are identified by network addresses, and may have hostnames. Hostnames serve as memorable labels for the nodes, rarely changed after initial assignment. Network addresses serve for locating and identifying the nodes by communication protocols such as the Internet Protocol. Computer networks may be classified by many criteria, including the transmission medium used to carry signals, bandwidth, communications pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symmetric Key
Symmetric-key algorithms are algorithms for cryptography that use the same cryptographic keys for both the encryption of plaintext and the decryption of ciphertext. The keys may be identical, or there may be a simple transformation to go between the two keys. The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link. The requirement that both parties have access to the secret key is one of the main drawbacks of symmetric-key encryption, in comparison to public-key encryption (also known as asymmetric-key encryption). However, symmetric-key encryption algorithms are usually better for bulk encryption. They have a smaller key size, which means less storage space and faster transmission. Due to this, asymmetric-key encryption is often used to exchange the secret key for symmetric-key encryption. Types Symmetric-key encryption can use either stream ciphers or block ciphers. * Stream ciphers encrypt the digits ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otway–Rees Protocol
The Otway–Rees protocol is a computer network authentication protocol designed for use on insecure networks (e.g. the Internet). It allows individuals communicating over such a network to prove their identity to each other while also preventing eavesdropping or replay attacks and allowing for the detection of modification. The protocol can be specified as follows in security protocol notation, where Alice is authenticating herself to Bob using a server S (M is a session-identifier, NA and NB are nonces): # A \rightarrow B: M,A,B,\_ # B \rightarrow S: M,A,B,\_,\_ # S \rightarrow B: M,\_,\_ # B \rightarrow A: M,\_ Note: The above steps do not authenticate B to A. This is one of the protocols analysed by Burrows, Abadi and Needham in the paper that introduced an early version of Burrows–Abadi–Needham logic. Attacks on the protocol There are a variety of attacks on this protocol currently published. Interception attacks These attacks leave the intruder with the session ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuman–Stubblebine Protocol
The Neuman–Stubblebine protocol is a computer network authentication protocol designed for use on insecure networks (e.g., the Internet). It allows individuals communicating over such a network to prove their identity to each other. This protocol utilizes time stamps, but does not depend on synchronized clocks. The protocol If Alice (A) initiates the communication to Bob (B) with S is a server trusted by both parties, the protocol can be specified as follows using security protocol notation: * A and B are identities of Alice and Bob respectively * M is a session identifier * K_ is a symmetric key known only to A and S * K_ is a symmetric key known only to B and S * N_A and N_B are nonces generated by A and B respectively * T_A and T_B are timestamps generated by A and B respectively * K_ is a generated symmetric key, which will be the session key of the session between A and B A \rightarrow B: A, N_A :Alice notified Bob of intent to initiate secure communication. B \rightarr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Needham–Schroeder Protocol
The Needham–Schroeder protocol is one of the two key transport protocols intended for use over an insecure network, both proposed by Roger Needham and Michael Schroeder. These are: * The ''Needham–Schroeder Symmetric Key Protocol'', based on a symmetric encryption algorithm. It forms the basis for the Kerberos protocol. This protocol aims to establish a session key between two parties on a network, typically to protect further communication. * The ''Needham–Schroeder Public-Key Protocol'', based on public-key cryptography. This protocol is intended to provide mutual authentication between two parties communicating on a network, but in its proposed form is insecure. The symmetric protocol Here, Alice (A) initiates the communication to Bob B. S is a server trusted by both parties. In the communication: * A and B are identities of Alice and Bob respectively * is a symmetric key known only to A and S * is a symmetric key known only to B and S * N_A and N_B are nonces gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerberos (protocol)
Kerberos () is a computer-network authentication protocol that works on the basis of ''tickets'' to allow nodes communicating over a non-secure network to prove their identity to one another in a secure manner. Its designers aimed it primarily at a client–server model, and it provides mutual authentication—both the user and the server verify each other's identity. Kerberos protocol messages are protected against eavesdropping and replay attacks. Kerberos builds on symmetric-key cryptography and requires a trusted third party, and optionally may use public-key cryptography during certain phases of authentication.RFC 4556, abstract. Kerberos uses UDP port 88 by default. The protocol was named after the character '' Kerberos'' (or ''Cerberus'') from Greek mythology, the ferocious three-headed guard dog of Hades. History and development Massachusetts Institute of Technology (MIT) developed Kerberos in 1988 to protect network services provided by Project Athena. The protocol is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alice And Bob
Alice and Bob are fictional characters commonly used as placeholders in discussions about cryptographic systems and protocols, and in other science and engineering literature where there are several participants in a thought experiment. The Alice and Bob characters were invented by Ron Rivest, Adi Shamir, and Leonard Adleman in their 1978 paper "A Method for Obtaining Digital Signatures and Public-key Cryptosystems". Subsequently, they have become common archetypes in many scientific and engineering fields, such as quantum cryptography, game theory and physics. As the use of Alice and Bob became more widespread, additional characters were added, sometimes each with a particular meaning. These characters do not have to refer to people; they refer to generic agents which might be different computers or even different programs running on a single computer. Overview Alice and Bob are the names of fictional characters used for convenience and to aid comprehension. For example, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Session Key
A session key is a single-use symmetric key used for encrypting all messages in one communication session. A closely related term is content encryption key (CEK), traffic encryption key (TEK), or multicast key which refers to any key used for encrypting messages, contrary to other uses like encrypting other keys (key encryption key (KEK) or key encryption has been made public key). Session keys can introduce complications into a system, yet they solve some real problems. There are two primary reasons to use session keys: # Several cryptanalytic attacks become easier the more material encrypted with a specific key is available. By limiting the amount of data processed using a particular key, those attacks are rendered harder to perform. # asymmetric encryption is too slow for many purposes, and all secret key algorithms require that the key is securely distributed. By using an asymmetric algorithm to encrypt the secret key for another, faster, symmetric algorithm, it's possible t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolute notion of time, however. They can have any epoch, can be relative to any arbitrary time, such as the power-on time of a system, or to some arbitrary time in the past. The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a time card. In modern times usage of the term has expanded to refer to digital date and time information attached to digital data. For example, computer files contain timestamps that tell when the file was last modified, and digital cameras add timestamps to the pictures they take, recording th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Authentication
Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicating a person or thing's identity, authentication is the process of verifying that identity. It might involve validating personal identity documents, verifying the authenticity of a website with a digital certificate, determining the age of an artifact by carbon dating, or ensuring that a product or document is not counterfeit. Methods Authentication is relevant to multiple fields. In art, antiques, and anthropology, a common problem is verifying that a given artifact was produced by a certain person or in a certain place or period of history. In computer science, verifying a user's identity is often required to allow access to confidential data or systems. Authentication can be considered to be of three types: The first type of au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Security Protocol Notation
In cryptography, security (engineering) protocol notation, also known as protocol narrations and Alice & Bob notation, is a way of expressing a protocol of correspondence between entities of a dynamic system, such as a computer network. In the context of a formal model, it allows reasoning about the properties of such a system. The standard notation consists of a set of principals (traditionally named Alice, Bob, Charlie, and so on) who wish to communicate. They may have access to a server S, shared keys K, timestamps T, and can generate nonces N for authentication purposes. A simple example might be the following: :A\rightarrow B:\_ This states that Alice intends a message for Bob consisting of a plaintext X encrypted under shared key KA,B. Another example might be the following: :B\rightarrow A:\_ This states that Bob intends a message for Alice consisting of a nonce NB encrypted using public key of Alice. A key with two subscripts, KA,B, is a symmetric key Symmetric-ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger Needham
Roger Michael Needham (9 February 1935 – 1 March 2003) was a British computer scientist. Early life and education Needham was born in Birmingham, England, the only child of Phyllis Mary, ''née'' Baker (''c''.1904–1976) and Leonard William Needham (''c''.1905–1973), a university chemistry lecturer. He attended Doncaster Grammar School for Boys in Doncaster (then in the West Riding) going on to St John's College, Cambridge in 1953, and graduating with a BA in 1956 in mathematics and philosophy. Herbert, Andrew James"Needham, Roger Michael (1935–2003)", ''Oxford Dictionary of National Biography'', Oxford University Press, March 2009; online edition, January 2007. Retrieved 27 August 2018 His PhD thesis was on applications of digital computers to the automatic classification and retrieval of documents. He worked on a variety of key computing projects in security, operating systems, computer architecture (capability systems) and local area networks. Career and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
