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Lai–Massey Scheme
The Lai–Massey scheme is a cryptographic structure used in the design of block ciphers. It is used in IDEA and IDEA NXT. The scheme was originally introduced by Xuejia LaiX. Lai. On the design and security of block ciphers'. ETH Series in Information Processing, vol. 1, Hartung-Gorre, Konstanz, 1992 with the assistance of James L. Massey, hence the scheme's name, ''Lai-Massey''. Design The Lai-Massey Scheme is similar to a Feistel Network in design, using a ''round function'' and a ''half-round function''. The round function is a function which takes two inputs, a sub-key and a Data block, and which returns one output of equal length to the Data block. The half-round function takes two inputs and transforms them into two outputs. For any given round, the input is split into two halves, ''left'' and ''right''. Initially, the inputs are passed through the half-round function. In each round, the difference between the inputs is passed to the round function along with a sub-ke ... [...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] |
International Data Encryption Algorithm
In cryptography, the International Data Encryption Algorithm (IDEA), originally called Improved Proposed Encryption Standard (IPES), is a symmetric-key block cipher designed by James Massey of ETH Zurich and Xuejia Lai and was first described in 1991. The algorithm was intended as a replacement for the Data Encryption Standard (DES). IDEA is a minor revision of an earlier cipher Proposed Encryption Standard (PES). The cipher was designed under a research contract with the Hasler Foundation, which became part of Ascom-Tech AG. The cipher was patented in a number of countries but was freely available for non-commercial use. The name "IDEA" is also a trademark. The last patents expired in 2012, and IDEA is now patent-free and thus completely free for all uses. IDEA was used in Pretty Good Privacy (PGP) v2.0 and was incorporated after the original cipher used in v1.0, BassOmatic, was found to be insecure. IDEA is an optional algorithm in the OpenPGP standard. Operation IDEA operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IDEA NXT
In cryptography, the IDEA NXT algorithm (previously known as FOX) is a block cipher designed by Pascal Junod and Serge Vaudenay of EPFL (Lausanne, Switzerland). It was conceived between 2001 and 2003. The project was originally named FOX and was published in 2003. In May 2005, it was announced by MediaCrypt under the name IDEA NXT. IDEA NXT is the successor to the International Data Encryption Algorithm (IDEA) and also uses the Lai–Massey scheme The Lai–Massey scheme is a cryptographic structure used in the design of block ciphers. It is used in IDEA and IDEA NXT. The scheme was originally introduced by Xuejia LaiX. Lai. On the design and security of block ciphers'. ETH Series in Infor .... MediaCrypt AG holds patents on elements of IDEA and IDEA NXT. The cipher is specified in two configurations: NXT64 (with block of 64 bits, key of 128 bits, 16 rounds) and NXT128 (with block of 128 bits, key of 256 bits, 16 rounds). References External links FOX Specifications Ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xuejia Lai
Xuejia Lai () is a cryptographer, currently a professor at Shanghai Jiao Tong University. His notable work includes the design of the block cipher IDEA based on the Lai-Massey scheme, the theory of Markov ciphers, and the cryptanalysis of a number of cryptographic hash functions. His book ''On the Design and Security of Block Ciphers'' () is frequently cited in cryptography papers. Lai received a B.Sc. in electrical engineering in 1982 and an M.Sc. in mathematics in 1984 at Xidian University (then known as ''Northwest Institute of Telecommunication Engineering''). About 1982 he met James Massey, who was visiting the university to give lectures in cryptography. Lai served as interpreter for these lectures. He later became one of Massey's doctoral students at ETH Zurich, where he received his Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for progra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Massey
James Lee Massey (February 11, 1934 – June 16, 2013) was an American information theorist and cryptographer, Professor Emeritus of Digital Technology at ETH Zurich. His notable work includes the application of the Berlekamp–Massey algorithm to linear codes, the design of the block ciphers IDEA (with Xuejia Lai, based on the Lai-Massey scheme) and SAFER, and the Massey-Omura cryptosystem (with Jim K. Omura). Biography Massey was born in Wauseon, Ohio. As a child, after the death of his father in Ohio, he moved with his mother and brother to Mendota, Illinois. At age 14, his family moved to Ottawa, Illinois. After graduating from St. Bede Academy, he entered the University of Notre Dame. He received a B.S. in electrical engineering from Notre Dame in 1956 and was granted an NSF Fellowship. After three years of military service, he began graduate studies in 1959 at MIT, where he concentrated on coding theory and was awarded a Ph.D. in 1962, with John Wozencraft as his advisor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lai Massey Scheme Diagram En
Lai or LAI may refer to: Abbreviations * Austrian Latin America Institute (Österreichisches Lateinamerika-Institut) * ''Latin American Idol'', TV series * La Trobe Institute, Melbourne, Australia * Leaf area index, leaf area of a crop or vegetation per unit ground area * Liga Atlética Interuniversitaria de Puerto Rico * Location Area Identity Places * Lai (state) (萊), 6th-century BC state in present-day Shandong, China *Bolyu language, also known as Lai * Laï, city in Chad * Lai, Iran (other), places in Iran * Lai, village in Lum Choar, Cambodia * ''Lai'', Romansch name for Lenzerheide, a village in Switzerland * Lannion – Côte de Granit Airport Surname * Francis Lai (1932–2018), French composer * Valentino Lai (born 1984), Swedish football player * Lai (surname) 黎丶賴, Chinese surname * Lí (surname 黎), Lai in Cantonese Other * Battle of Lai, during World War I * Lai people, ethnic group of Mizoram, North East India * Lai languages The Lai lang ... [...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] |
Encryption
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decipher a ciphertext back to plaintext and access the original information. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is possible to decrypt the message without possessing the key but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users. Historically, various forms of encryption have been used to aid in cryptography. Early encryption techniques were often used in military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decryption
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decipher a ciphertext back to plaintext and access the original information. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is possible to decrypt the message without possessing the key but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users. Historically, various forms of encryption have been used to aid in cryptography. Early encryption techniques were often used in military ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Schedule
In cryptography, the so-called product ciphers are a certain kind of cipher, where the (de-)ciphering of data is typically done as an iteration of ''rounds''. The setup for each round is generally the same, except for round-specific fixed values called a round constant, and round-specific data derived from the cipher key called a round key. A key schedule is an algorithm that calculates all the round keys from the key. Some types of key schedules *Some ciphers have simple key schedules. For example, the block cipher TEA splits the 128-bit key into four 32-bit pieces and uses them repeatedly in successive rounds. *DES has a key schedule in which the 56-bit key is divided into two 28-bit halves; each half is thereafter treated separately. In successive rounds, both halves are rotated left by one or two bits (specified for each round), and then 48 round key bits are selected by Permuted Choice 2 (PC-2) – 24 bits from the left half and 24 from the right. The rotations have t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feistel Structure
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] |
