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Block Ciphers
In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified elementary components in the design of many cryptographic protocols and are widely used to 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 modes of operation have been designed to allow their repeated use in a secure way to achieve the security goals of confidentiality and 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 other for decryption, . Both algorithms accept two inputs: an input block of size bits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptography
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Communication Theory Of Secrecy Systems
"Communication Theory of Secrecy Systems" is a paper published in 1949 by Claude Shannon discussing cryptography from the viewpoint of information theory. It is one of the foundational treatments (arguably ''the'' foundational treatment) of modern cryptography. It is also a proof that all theoretically unbreakable ciphers must have the same requirements as the one-time pad. Shannon published an earlier version of this research in the formerly classified report ''A Mathematical Theory of Cryptography,'' Memorandum MM 45-110-02, Sept. 1, 1945, Bell Laboratories. This report also precedes the publication of his "A Mathematical Theory of Communication", which appeared in 1948. See also * Confusion and diffusion * Product cipher * One-time pad * Unicity distance References * Shannon, Claude. "Communication Theory of Secrecy Systems", ''Bell System Technical Journal The ''Bell Labs Technical Journal'' is the in-house scientific journal for scientists of Nokia Bell Labs, published year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atalla Key Block
Atalla may refer to: *Mohamed M. Atalla, Egyptian-American semiconductor and cybersecurity pioneer, also known by the alias "John" or "Martin" M. Atalla *Utimaco Atalla, Information Protection and Control Suite (data security software) company, founded by Mohamed Atalla *Ash Atalla, a British television producer *Andrew Atalla Andrew Atalla (Born May 5, 1980) is an Entrepreneur and founder of London-based online marketing agency atom42 in April 2007 and won the Startups.co.uk Young Entrepreneur of the Year award in November 2009. Clients of atom42 include match.com, Th ..., the British founder of online marketing agency atom42 *The former name of Epworth, Georgia See also * Attala (other) {{disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American National Standards Institute
The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. ANSI accredits standards that are developed by representatives of other standards organizations, government agencies, consumer groups, companies, and others. These standards ensure that the characteristics and performance of products are consistent, that people use the same definitions and terms, and that products are tested the same way. ANSI also accredits organizations that carry out product or personnel certification in accordance with requirements defined in international standards. The organization's headquarters are in Washington, D.C. ANSI's operations office is located in New York City. The ANSI annual operating b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Payment Card Industry Data Security Standard
The Payment Card Industry Data Security Standard (PCI DSS) is an information security standard used to handle credit cards from major card brands. The standard is administered by the Payment Card Industry Security Standards Council and its use is mandated by the card brands. The standard was created to better control cardholder data and reduce credit card fraud. Validation of compliance is performed annually or quarterly, by a method suited to the volume of transactions handled: * Self-Assessment Questionnaire (SAQ) * Firm-specific Internal Security Assessor (ISA) * External Qualified Security Assessor (QSA) History Originally, the major card brands started five different security programs: *Visa's Cardholder Information Security Program * MasterCard's Site Data Protection *American Express's Data Security Operating Policy *Discover's Information Security and Compliance * JCB's Data Security Program The intentions of each were roughly similar: to create an additional level of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic
Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substitution–permutation Network
In cryptography, an SP-network, or substitution–permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES (Rijndael), 3-Way, Kalyna, Kuznyechik, PRESENT, SAFER, SHARK, and Square. Such a network takes a block of the plaintext and the key as inputs, and applies several alternating ''rounds'' or ''layers'' of substitution boxes (S-boxes) and permutation boxes (P-boxes) to produce the ciphertext block. The S-boxes and P-boxes transform of input bits into output bits. It is common for these transformations to be operations that are efficient to perform in hardware, such as exclusive or (XOR) and bitwise rotation. The key is introduced in each round, usually in the form of "round keys" derived from it. (In some designs, the S-boxes themselves depend on the key.) Decryption is done by simply reversing the process (using the inverses of the S-boxes and P-boxes and applying the round keys in reversed order). Components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Encryption Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael (), is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001. AES is a variant of the Rijndael block cipher developed by two Belgian cryptographers, Joan Daemen and Vincent Rijmen, who submitted a proposal to NIST during the AES selection process. Rijndael is a family of ciphers with different key and block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits. AES has been adopted by the U.S. government. It supersedes the Data Encryption Standard (DES), which was published in 1977. The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data. In the United States, AES was announced by the NIST as U.S. FIPS PUB 197 (FIPS 197) on Novemb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Encryption Standard
The Data Encryption Standard (DES ) is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cryptography. Developed in the early 1970s at IBM and based on an earlier design by Horst Feistel, the algorithm was submitted to the National Bureau of Standards (NBS) following the agency's invitation to propose a candidate for the protection of sensitive, unclassified electronic government data. In 1976, after consultation with the National Security Agency (NSA), the NBS selected a slightly modified version (strengthened against differential cryptanalysis, but weakened against brute-force attacks), which was published as an official Federal Information Processing Standard (FIPS) for the United States in 1977. The publication of an NSA-approved encryption standard led to its quick international adoption and widespread academic scrutiny. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horst Feistel
Horst Feistel (January 30, 1915 – November 14, 1990) was a German-American cryptographer who worked on the design of ciphers at IBM, initiating research that culminated in the development of the Data Encryption Standard (DES) in the 1970s. The structure used in DES, called a Feistel network, is commonly used in many block ciphers. Life and work Feistel was born in Berlin, Germany in 1915, and moved to the United States in 1934. During World War II, he was placed under house arrest, but gained US citizenship on 31 January 1944. The following day he was granted a security clearance and began work for the US Air Force Cambridge Research Center (AFCRC) on Identification Friend or Foe (IFF) devices until the 1950s. He was subsequently employed at MIT's Lincoln Laboratory, then the MITRE corporation. Finally, he moved to IBM, where he received an award for his cryptographic work. His research at IBM led to the development of the Lucifer and Data Encryption Standard (DES) ciphers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feistel Network
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] |
Bell System Technical Journal
The ''Bell Labs Technical Journal'' is the in-house scientific journal for scientists of Nokia Bell Labs, published yearly by the IEEE society. The managing editor is Charles Bahr. The journal was originally established as the ''Bell System Technical Journal'' (BSTJ) in New York by the American Telephone and Telegraph Company (AT&T) in 1922, published under this name until 1983, when the breakup of the Bell System placed various parts of the system into separate companies. The journal was devoted to the scientific fields and engineering disciplines practiced in the Bell System for improvements in the wide field of electrical communication. After the restructuring of Bell Labs in 1984, the journal was renamed to ''AT&T Bell Laboratories Technical Journal''. In 1985, it was published as the ''AT&T Technical Journal'' until 1996, when it was renamed to ''Bell Labs Technical Journal''. History The ''Bell System Technical Journal'' was published by AT&T in New York City through its I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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