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Py (cipher)
Py is a stream cipher submitted to eSTREAM by Eli Biham and Jennifer Seberry. It is one of the fastest eSTREAM candidates at around 2.6 cycles per byte on some platforms. It has a structure a little like RC4, but adds an array of 260 32-bit words which are indexed using a permutation of bytes, and produces 64 bits in each round. The authors assert that the name be pronounced "Roo", a reference to the cipher's Australian origin, by reading the letters "Py" as Cyrillic (Ру) rather than Latin characters. This somewhat perverse pronunciation is understood to be their answer, in jest, to the difficult-to-pronounce name ''Rijndael'' for the cipher which was adopted as the Advanced Encryption Standard. * The original April 2005 proposal included the cipher Py, and a simplified version Py6. The latter reduces the size of some internal tables, providing greatly reduced key scheduling cost, at the expense of a shorter maximum output length. * In June 2006, the authors described Pypy (e ... [...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] |
Circular Buffer
In computer science, a circular buffer, circular queue, cyclic buffer or ring buffer is a data structure that uses a single, fixed-size buffer as if it were connected end-to-end. This structure lends itself easily to buffering data streams. There were early circular buffer implementations in hardware. Overview A circular buffer first starts out empty and has a set length. In the diagram below is a 7-element buffer: : Assume that 1 is written in the center of a circular buffer (the exact starting location is not important in a circular buffer): : Then assume that two more elements are added to the circular buffer — 2 & 3 — which get put after 1: : If two elements are removed, the two oldest values inside of the circular buffer would be removed. Circular buffers use FIFO (''first in, first out'') logic. In the example, 1 & 2 were the first to enter the circular buffer, they are the first to be removed, leaving 3 inside of the buffer. : If the buffer has 7 ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signal Processor
A digital signal processor (DSP) is a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing. DSPs are fabricated on MOS integrated circuit chips. They are widely used in audio signal processing, telecommunications, digital image processing, radar, sonar and speech recognition systems, and in common consumer electronic devices such as mobile phones, disk drives and high-definition television (HDTV) products. The goal of a DSP is usually to measure, filter or compress continuous real-world analog signals. Most general-purpose microprocessors can also execute digital signal processing algorithms successfully, but may not be able to keep up with such processing continuously in real-time. Also, dedicated DSPs usually have better power efficiency, thus they are more suitable in portable devices such as mobile phones because of power consumption constraints. DSPs often use special memory architectures that are able t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Crowley (cryptographer)
Paul Crowley may refer to: * Paul Crowley (footballer) (born 1980), Irish footballer * Paul Crowley (ice hockey) Paul Crowley (born December 26, 1955) is a Canadian former professional ice hockey winger who played in the World Hockey Association (WHA). Career Drafted in the tenth round of the 1975 NHL Amateur Draft by the Toronto Maple Leafs, Crowley was ... (born 1955), Canadian ice hockey player * Paul F. Crowley (born 1934), member of the Pennsylvania House of Representatives {{human name disambiguation, Crowley, Paul ... [...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] |
Keystream
In cryptography, a keystream is a stream of random or pseudorandom characters that are combined with a plaintext message to produce an encrypted message (the ciphertext). The "characters" in the keystream can be bits, bytes, numbers or actual characters like A-Z depending on the usage case. Usually each character in the keystream is either added, subtracted or XORed with a character in the plaintext to produce the ciphertext, using modular arithmetic. Keystreams are used in the one-time pad cipher and in most stream ciphers. Block ciphers can also be used to produce keystreams. For instance, CTR mode is a block mode that makes a block cipher produce a keystream and thus turns the block cipher into a stream cipher. Example In this simple example we use the English alphabet of 26 characters from a-z. Thus we can not encrypt numbers, commas, spaces and other symbols. The random numbers in the keystream then have to be at least between 0 and 25. To encrypt we add the keystream nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hongjun Wu
Hongjun Laozu () lit. "Ancestor of the Great Balance" is a deity in Chinese folk religion and Taoism, teacher of the Three Pure Ones in Taoist mythology. ''Hongjun'' is a graphic variant of ''hungjun'' () "primordial nature", as used in the Chinese idiom ''Xian you hongjun hou you tian'' "First there was Hongjun and then there was Heaven". Daoists mythologize Hongjun Laozu as the ancestor of ''xian'' "trancendents; immortals" (Werner 1922:133-134) and use the honorific name Hongyuan Laozu () "Great Primal Ancestor". In Chinese creation myths, ''hongyuan'' or is a cosmological term for "the universe before the separation of heaven and earth". Some myths about the creator Pangu (Werner 1922:128-130) refer to Hongjun Laozu as Xuanxuan Shangren () "Mystery of Mysteries Saint" (a reference to the ''Daodejing'' 1, tr. Mair 1990:59, "Mystery or mysteries, the gate of all wonders!"). Hongjun Laozu is also referred to as Hunyuan Laozu (混元老祖 - "Ancestor of Original Chaos"). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESTREAM
eSTREAM is a project to "identify new stream ciphers suitable for widespread adoption", organised by the EU ECRYPT network. It was set up as a result of the failure of all six stream ciphers submitted to the NESSIE project. The call for primitives was first issued in November 2004. The project was completed in April 2008. The project was divided into separate phases and the project goal was to find algorithms suitable for different application profiles. Profiles The submissions to eSTREAM fall into either or both of two profiles: * Profile 1: "Stream ciphers for software applications with high throughput requirements" * Profile 2: "Stream ciphers for hardware applications with restricted resources such as limited storage, gate count, or power consumption." Both profiles contain an "A" subcategory (1A and 2A) with ciphers that also provide authentication in addition to encryption. In Phase 3 none of the ciphers providing authentication are being considered (The NLS cipher had a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bart Preneel
Bart Preneel (born 15 October 1963 in Leuven, Belgium) is a Flemish cryptographer and cryptanalyst. He is a professor at Katholieke Universiteit Leuven, in the COSIC group. He was the president of the International Association for Cryptologic Research in 2008-2013 and project manager of ECRYPT. Education In 1987, Preneel received an electrical engineering degree in applied science from the Katholieke Universiteit, Leuven. In 1993, Preneel received a PhD from the Katholieke Universiteit Leuven. His dissertation in computer science, entitled ''Analysis and Design of Cryptographic Hash Functions'', was advised by Joos (Joseph) P. L. Vandewalle and René J. M. Govaerts. Career Along with Shoji Miyaguchi, he independently invented the Miyaguchi–Preneel scheme, a complex structure used in the hash function Whirlpool. He is one of the authors of the RIPEMD-160 hash function. He was also a co-inventor of the stream cipher MUGI which would later become a Japanese standard, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Souradyuti Paul
Souradyuti Paul (born 1976) is an Indian cryptologist. Formerly a member of COSIC, he is currently working as an associate professor at Indian Institute of Technology Bhilai and a Guest Researcher for the National Institute of Standards and Technology in the United States. He participated in cryptanalysis of RC4, Helix A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helic ... and Py family of ciphers among others. He has co-designed the following ciphers * RC4A * RCR-32, RCR-64. He also contributed to the design of a hash function iteration mode of operation Fast-widepipe.Mridul Nandi and Souradyuti Paul. Speeding Up the Widepipe: Secure and Fast Hashing. In Guang Gong and Kishan Gupta, editor, Indocrypt 2010, Springer, 2010. While working at NIST Dr. Paul has worked towards the develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
