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Simon (cipher)
Simon is a family of lightweight block ciphers publicly released by the National Security Agency (NSA) in June 2013. Simon has been optimized for performance in hardware implementations, while its sister algorithm, Speck, has been optimized for software implementations. The NSA began working on the Simon and Speck ciphers in 2011. The agency anticipated some agencies in the US federal government would need a cipher that would operate well on a diverse collection of Internet of Things devices while maintaining an acceptable level of security. Description of the cipher The Simon block cipher is a balanced Feistel cipher with an ''n''-bit word, and therefore the block length is 2''n''. The key length is a multiple of ''n'' by 2, 3, or 4, which is the value ''m''. Therefore, a Simon cipher implementation is denoted as Simon2''n''/''nm''. For example, Simon64/128 refers to the cipher operating on a 64-bit plaintext block (''n'' = 32) that uses a 128-bit key. The block ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simon Block Cipher
Simon may refer to: People * Simon (given name), including a list of people and fictional characters with the given name Simon * Simon (surname), including a list of people with the surname Simon * Eugène Simon, French naturalist and the genus authority ''Simon'' * Tribe of Simeon, one of the twelve tribes of Israel Places * Şimon ( hu, links=no, Simon), a village in Bran, Brașov, Bran Commune, Braşov County, Romania * Șimon, a right tributary of the river Turcu in Romania Arts, entertainment, and media Films * Simon (1980 film), ''Simon'' (1980 film), starring Alan Arkin * Simon (2004 film), ''Simon'' (2004 film), Dutch drama directed by Eddy Terstall Games * Simon (game), ''Simon'' (game), a popular computer game * Simon Says, children's game Literature * Simon (Sutcliff novel), ''Simon'' (Sutcliff novel), a children's historical novel written by Rosemary Sutcliff * Simon (Sand novel), an 1835 novel by George Sand * ''Simon Necronomicon'' (1977), a purported grimoire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hash Function
A hash function is any function that can be used to map data of arbitrary size to fixed-size values. The values returned by a hash function are called ''hash values'', ''hash codes'', ''digests'', or simply ''hashes''. The values are usually used to index a fixed-size table called a ''hash table''. Use of a hash function to index a hash table is called ''hashing'' or ''scatter storage addressing''. Hash functions and their associated hash tables are used in data storage and retrieval applications to access data in a small and nearly constant time per retrieval. They require an amount of storage space only fractionally greater than the total space required for the data or records themselves. Hashing is a computationally and storage space-efficient form of data access that avoids the non-constant access time of ordered and unordered lists and structured trees, and the often exponential storage requirements of direct access of state spaces of large or variable-length keys. Use of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual EC DRBG
Dual_EC_DRBG (Dual Elliptic Curve Deterministic Random Bit Generator) is an algorithm that was presented as a cryptographically secure pseudorandom number generator (CSPRNG) using methods in elliptic curve cryptography. Despite wide public criticism, including the public identification of a backdoor, it was for seven years one of four CSPRNGs standardized in NIST SP 800-90A as originally published circa June 2006, until it was withdrawn in 2014. Weakness: a potential backdoor Weaknesses in the cryptographic security of the algorithm were known and publicly criticised well before the algorithm became part of a formal standard endorsed by the ANSI, ISO, and formerly by the National Institute of Standards and Technology (NIST). One of the weaknesses publicly identified was the potential of the algorithm to harbour a kleptographic backdoor advantageous to those who know about it—the United States government's National Security Agency (NSA)—and no one else. In 2013, ''The New ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Organization For Standardization
The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Article 3 of the ISO Statutes. ISO was founded on 23 February 1947, and (as of November 2022) it has published over 24,500 international standards covering almost all aspects of technology and manufacturing. It has 809 Technical committees and sub committees to take care of standards development. The organization develops and publishes standardization in all technical and nontechnical fields other than electrical and electronic engineering, which is handled by the IEC.Editors of Encyclopedia Britannica. 3 June 2021.International Organization for Standardization" ''Encyclopedia Britannica''. Retrieved 2022-04-26. It is headquartered in Geneva, Switzerland, and works in 167 countries . The three official languages of the ISO are English, Fren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weak Key
In cryptography, a weak key is a key, which, used with a specific cipher, makes the cipher behave in some undesirable way. Weak keys usually represent a very small fraction of the overall keyspace, which usually means that, if one generates a random key to encrypt a message, weak keys are very unlikely to give rise to a security problem. Nevertheless, it is considered desirable for a cipher to have no weak keys. A cipher with no weak keys is said to have a ''flat'', or ''linear'', key space. Historical origins Virtually all rotor-based cipher machines (from 1925 onwards) have implementation flaws that lead to a substantial number of weak keys being created. Some rotor machines have more problems with weak keys than others, as modern block and stream ciphers do. The first stream cipher machines were also rotor machines and had some of the same problems of weak keys as the more traditional rotor machines. The T52 was one such stream cipher machine that had weak key problems. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distinguishing Attack
In cryptography, a distinguishing attack is any form of cryptanalysis on data encrypted by a cipher that allows an attacker to distinguish the encrypted data from random data. Modern symmetric-key ciphers are specifically designed to be immune to such an attack. In other words, modern encryption schemes are pseudorandom permutations and are designed to have ciphertext indistinguishability. If an algorithm is found that can distinguish the output from random faster than a brute force search, then that is considered a break of the cipher. A similar concept is the known-key distinguishing attack, whereby an attacker knows the key and can find a structural property in cipher, where the transformation from plaintext to ciphertext is not random. Overview To prove that a cryptographic function is safe, it is often compared to a random oracle. If a function would be a random oracle, then an attacker is not able to predict any of the output of the function. If a function is distinguisha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotational Cryptanalysis
In cryptography, rotational cryptanalysis is a generic cryptanalytic attack against algorithms that rely on three operations: modular addition, rotation and XOR — ARX for short. Algorithms relying on these operations are popular because they are relatively cheap in both hardware and software and run in constant time, making them safe from timing attacks in common implementations. The basic idea of rotational cryptanalysis is that both the bit rotation and XOR operations preserve correlations between bit-rotated pairs of inputs, and that addition of bit-rotated inputs also partially preserves bit rotation correlations. Rotational pairs of inputs can thus be used to "see through" the cipher's cascaded ARX operations to a greater degree than might be expected. This ability to "see" correlations through rounds of processing can then be exploited to break the cipher in a way that is similar to differential cryptanalysis. The term "rotational cryptanalysis" was coined by Dmitry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Attack
The slide attack is a form of cryptanalysis designed to deal with the prevailing idea that even weak ciphers can become very strong by increasing the number of rounds, which can ward off a differential attack. The slide attack works in such a way as to make the number of rounds in a cipher irrelevant. Rather than looking at the data-randomizing aspects of the block cipher, the slide attack works by analyzing the key schedule and exploiting weaknesses in it to break the cipher. The most common one is the keys repeating in a cyclic manner. The attack was first described by David Wagner and Alex Biryukov. Bruce Schneier first suggested the term ''slide attack'' to them, and they used it in their 1999 paper describing the attack. The only requirements for a slide attack to work on a cipher is that it can be broken down into multiple rounds of an identical ''F'' function. This probably means that it has a cyclic key schedule. The ''F'' function must be vulnerable to a known-plainte ... [...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] |
Cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Even though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salsa20
Salsa20 and the closely related ChaCha are stream ciphers developed by Daniel J. Bernstein. Salsa20, the original cipher, was designed in 2005, then later submitted to the eSTREAM European Union cryptographic validation process by Bernstein. ChaCha is a modification of Salsa20 published in 2008. It uses a new round function that increases diffusion and increases performance on some architectures. Both ciphers are built on a pseudorandom function based on add-rotate-XOR (ARX) operations — 32-bit addition, bitwise addition (XOR) and rotation operations. The core function maps a 256-bit key, a 64-bit nonce, and a 64-bit counter to a 512-bit block of the key stream (a Salsa version with a 128-bit key also exists). This gives Salsa20 and ChaCha the unusual advantage that the user can efficiently seek to any position in the key stream in constant time. Salsa20 offers speeds of around 4–14 cycles per byte in software on modern x86 processors, and reasonable hardware performance. I ... [...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] |
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