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LION (cipher)
The BEAR and LION block ciphers were invented by Ross Anderson and Eli Biham by combining a stream cipher and a cryptographic hash function. The algorithms use a very large variable block size, on the order of 213 to 223 bits . Both are 3-round generalized (alternating) Feistel ciphers, using the hash function and the stream cipher as round functions. BEAR uses the hash function twice with independent keys Key or The Key may refer to: Common meanings * Key (cryptography), a piece of information that controls the operation of a cryptography algorithm * Key (lock), device used to control access to places or facilities restricted by a lock * Key (map ..., and the stream cipher once. LION uses the stream cipher twice and the hash function once. The inventors proved that an attack on either BEAR or LION that recovers the key would break both the stream cipher and the hash. References * * * Feistel ciphers {{crypto-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block Cipher
In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and are widely used to encryption, encrypt large amounts of data, including in data exchange protocols. A block cipher uses blocks as an unvarying transformation. Even a secure block cipher is suitable for the encryption of only a single block of data at a time, using a fixed key. A multitude of block cipher modes of operation, modes of operation have been designed to allow their repeated use in a secure way to achieve the security goals of confidentiality and authentication, authenticity. However, block ciphers may also feature as building blocks in other cryptographic protocols, such as universal hash functions and pseudorandom number generators. Definition A block cipher consists of two paired algorithms, one for encryption, , and the othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross J
Ross or ROSS may refer to: People * Clan Ross, a Highland Scottish clan * Ross (name), including a list of people with the surname or given name Ross, as well as the meaning * Earl of Ross, a peerage of Scotland Places * RoSS, the Republic of South Sudan Antarctica * Ross Sea * Ross Ice Shelf * Ross Dependency Australia * Ross, Tasmania Chile * Ross Casino, a former casino in Pichilemu, Chile; now the Agustín Ross Cultural Centre Ireland *"Ross", a common nickname for County Roscommon * Ross, County Mayo, a townland in Killursa civil parish, barony of Clare, County Mayo, bordering Moyne Townland * Ross, County Westmeath, a townland in Noughaval civil parish, barony of Kilkenny West, County Westmeath * Ross, County Wexford * The Diocese of Ross in West Cork. The Roman Catholic diocese merged with Cork in 1958 to become the Roman Catholic Diocese of Cork and Ross, while the Church of Ireland diocese is now part of the Diocese of Cork, Cloyne and Ross. This area, centered aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eli Biham
Eli Biham ( he, אלי ביהם) is an Israeli cryptographer and cryptanalyst, currently a professor at the Technion - Israel Institute of Technology Computer Science department. Starting from October 2008 and till 2013, Biham was the dean of the Technion Computer Science department, after serving for two years as chief of CS graduate school. Biham received his Ph.D. for inventing (publicly) differential cryptanalysis, while working under Adi Shamir. It had, it turned out, been invented at least twice before. A team at IBM discovered it during their work on DES, and was requested/required to keep their discovery secret by the NSA, who evidently knew about it as well. Contributions to cryptanalysis Among his many contributions to cryptanalysis one can count: * differential cryptanalysis - publicly invented during his Ph.D. studies under Adi Shamir * Attacking all triple modes of operation. * impossible differential cryptanalysis - joint work with Adi Shamir and Alex Biryukov * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Cipher
stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream, to give a digit of the ciphertext stream. Since encryption of each digit is dependent on the current state of the cipher, it is also known as ''state cipher''. In practice, a digit is typically a bit and the combining operation is an exclusive-or (XOR). The pseudorandom keystream is typically generated serially from a random seed value using digital shift registers. The seed value serves as the cryptographic key for decrypting the ciphertext stream. Stream ciphers represent a different approach to symmetric encryption from block ciphers. Block ciphers operate on large blocks of digits with a fixed, unvarying transformation. This distinction is not always clear-cut: in some modes of operation, a block cipher primitive is used in such a w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Hash Function
A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with fixed size of n bits) that has special properties desirable for cryptography: * the probability of a particular n-bit output result (hash value) for a random input string ("message") is 2^ (like for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a ''pre-image'') is unfeasible, unless the value is selected from a known pre-calculated dictionary (" rainbow table"). The ''resistance'' to such search is quantified as security strength, a cryptographic hash with n bits of hash value is expected to have a ''preimage resistance'' strength of n bits. A ''second preimage'' resistance strength, with the same expectations, refers to a similar problem of finding a second message that matches the given hash value when one message is already known; * finding any pair of different messa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block Size (cryptography)
In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. Block ciphers operate on a fixed length string of bits. The length of this bit string is the block size. Both the input (plaintext) and output (ciphertext) are the same length; the output cannot be shorter than the input this follows logically from the pigeonhole principle and the fact that the cipher must be reversibleand it is undesirable for the output to be longer than the input. Until the announcement of NIST's AES contest, the majority of block ciphers followed the example of the DES in using a block size of 64 bits (8 bytes). However the birthday paradox tells us that after accumulating a number of blocks equal to the square root of the total number possible, there will be an approximately 50% chance of two or more being the same, which would start to leak information about the message contents. Thus even when used with a proper encryption mode (e.g. CBC or OFB), only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feistel Cipher
In cryptography, a Feistel cipher (also known as Luby–Rackoff block cipher) is a symmetric structure used in the construction of block ciphers, named after the German-born physicist and cryptographer Horst Feistel, who did pioneering research while working for IBM; it is also commonly known as a Feistel network. A large proportion of block ciphers use the scheme, including the US Data Encryption Standard, the Soviet/Russian GOST and the more recent Blowfish and Twofish ciphers. In a Feistel cipher, encryption and decryption are very similar operations, and both consist of iteratively running a function called a "round function" a fixed number of times. History Many modern symmetric block ciphers are based on Feistel networks. Feistel networks were first seen commercially in IBM's Lucifer cipher, designed by Horst Feistel and Don Coppersmith in 1973. Feistel networks gained respectability when the U.S. Federal Government adopted the DES (a cipher based on Lucifer, with changes mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key (cryptography)
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key’s security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the key pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selected Areas In Cryptography
Selected Areas in Cryptography (SAC) is an international cryptography conference (originally a workshop) held every August in Canada since 1994. The first workshop was organized by Carlisle Adams, Henk Meijer, Stafford Tavares and Paul van Oorschot. Through 1999, SAC was hosted at either Queen's University or Carleton University, but starting in 2000, locations have ranged across Canada. SAC has featured research presentations on many cryptographic topics, with a traditional focus on the design and analysis of block ciphers. SAC is regarded as a high-quality venue for presenting cryptographic results, and is the only cryptography conference held annually in Canada. Since 2003, SAC has included an invited lecture called the Stafford Tavares Lecture, in honor of one of its original organizers and strongest supporters. Each year, SAC features four topics: # Design and analysis of symmetric key primitives and cryptosystems including block and stream ciphers, hash functions, MAC alg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PostScript
PostScript (PS) is a page description language in the electronic publishing and desktop publishing realm. It is a dynamically typed, concatenative programming language. It was created at Adobe Systems by John Warnock, Charles Geschke, Doug Brotz, Ed Taft and Bill Paxton from 1982 to 1984. History The concepts of the PostScript language were seeded in 1976 by John Gaffney at Evans & Sutherland, a computer graphics company. At that time Gaffney and John Warnock were developing an interpreter for a large three-dimensional graphics database of New York Harbor. Concurrently, researchers at Xerox PARC had developed the first laser printer and had recognized the need for a standard means of defining page images. In 1975-76 Bob Sproull and William Newman developed the Press format, which was eventually used in the Xerox Star system to drive laser printers. But Press, a data format rather than a language, lacked flexibility, and PARC mounted the Interpress effort to create a succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
