wiktionary hashHash may refer to Hash symbol , the glyph Hash mark disambiguation , one of various symbols Hash food , a coarse mixture of ingredients Hash chain , a method of producing many one time keys from a single key or password Hash function , a derivation of data Cryptographic hash function Hash table , a data structure hash Unix , an operating system command Hashish , a psychoactive drug Hash House Harriers , a running club Fragment identifier , in computer hypertext, a string of characters that refers to a subordinate resource Geohash , a spatial data structure which subdivides space into buckets of grid shape disambiguation cs Hash de Hash hu Hash egy rtelm s t lap nl Hash ja pl Hash ru sv Hash th ... more details
In cryptography , N Hash is a cryptographic hash function based on the FEAL round function, and is now considered insecure. It was proposed in 1990 by Miyaguchi et al. weaknesses were published the following year. N Hash has a 128 bit hash size. A message is divided into 128 bit blocks, and each block is combined with the hash value computed so far using the g One way compression function compression function . g contains eight rounds, each of which uses an F function, similar to the one used by FEAL . Eli Biham and Adi Shamir 1991 applied the technique of differential cryptanalysis to N Hash, and showed that hash collision collision s could be generated faster than by a birthday attack for N Hash variants with even up to 12 rounds. References Eli Biham, Adi Shamir Differential Cryptanalysis of Feal and N Hash. EUROCRYPT 1991 1&ndash 16 S. Miyaguchi, K. Ohta, and M. Iwata 128 bit hash function N hash , NTT Review, 2 6 , November 1990, pp128&ndash 132. Crypto navbox hash Category Cryptographic hash functions crypto stub fr N hash it N Hash pl Funkcja N Hash ru N Hash ... more details
Hash mark may refer to Hash marks , a marking on hockey rinks and gridiron football fields Hatch mark , a form of mathematical notation Hash symbol , the glyph Service stripe , a military decoration Tally mark , a counting notation See also Hash disambiguation dab ... more details
Unreferenced date March 2009 In computer science , a hash list is typically a List computing list of Hash ... different purposes, such as fast table lookup hash table s and distributed databases distributed hash table s . This article covers hash lists that are used to guarantee data integrity. Image Hash list.svg thumb 350px right A hash list with a top hash A hash list is an extension of the old concept of hashing an item for instance, a file . A hash list is usually sufficient for most needs, but a more advanced form of the concept is a hash tree . Hash lists can be used to protect any kind of data stored, handled and transferred in and between computers. An important use of hash lists is to make ... a cryptographic hash function such as SHA 1 is used for the hashing. If the hash list only needs to protect ... be used. Hash lists are better than a simple hash of the entire file since, in the case of a data block ... a hash of the file, many undamaged blocks would have to be redownloaded, and the file reconstructed and tested until the correct hash of the entire file is obtained. Hash lists also protect against nodes ... from some other source. Root hash Often, an additional hash of the hash list itself a top hash , also called root hash or master hash is used. Before downloading a file on a p2p network, in most cases the top hash is acquired from a trusted source, for instance a friend or a web site that is known to have good recommendations of files to download. When the top hash is available, the hash list can be received from any non trusted source, like any peer in the p2p network. Then the received hash list is checked against the trusted top hash, and if the hash list is damaged or fake, another hash list from another source will be tried until the program finds one that matches the top hash. In some systems like for example BitTorrent protocol BitTorrent , instead of a top hash the whole hash list ..., a hash list and some additional data. See also Hash tree Hash table Hash chain Ed2k URI scheme , which ... more details
Image Hash tree.png thumb 300px right A binary hash tree In cryptography and computer science Hash trees or Merkle trees are a type of data structure Cn reason How do hash trees fit WP s definition of data ... about a larger piece of data for instance a file used to verify its contents. Hash trees are a combination of hash list s and hash chain ing, which in turn are extensions of hash function hash ing. Hash trees in which the underlying hash function is Tiger cryptography Tiger are often called Tiger trees or Tiger tree hashes . Uses Hash trees can be used to verify any kind of data stored, handled and transferred in and between computers. Currently the main use of hash trees is to make sure that data ... been made to use hash trees in trusted computing systems. Sun Microsystems has used Hash Trees in the ZFS ... End to End Data Integrity ref Hash Trees are used in Google Wave protocol, ref Google Wave Federation ... tree is a hierarchical hash verification if the hash over the entire keyspace is not the same ... replicas which contain mostly similar data. http www.aosabook.org en nosql.html ref Hash trees ... be used to sign a single message. But combined with hash trees they can be used for many messages and then become a Merkle signature scheme fairly efficient digital signature scheme . How hash trees work A hash tree is a Binary tree tree of Hash function hashes in which the leaves are hashes of data ... children. For example, in the picture hash 0 is the result of hashing hash 0 0 and then hash 0 1 . That is, hash 0 hashhash 0 0 hash 0 1 where denotes concatenation. Most hash tree ... nodes under each node. Usually, a cryptographic hash function such as SHA 1 , Whirlpool hash Whirlpool , or Tiger hash Tiger is used for the hashing. If the hash tree only needs to protect against .... In the top of a hash tree there is a top hash or root hash or master hash . Before downloading a file on a p2p network, in most cases the top hash is acquired from a trusted source, for instance a friend ... more details
Hash key can have several meanings. For its use to describe the key on a telephone keypad, see number sign . For its use in data structure, database and cryptographic applications, see hash function or unique key . Disambig ... more details
Multiple issues wikify January 2011 orphan January 2011 date January 2011 File Hash fossil.JPG thumb 245px A fossil hashHash fossils are not actually one fossil , they are many fossils in the same Rock geology rock . The term hash fossil describes the fossil formed when all the organic material in an environment falls to the ocean floor and fossilizes, hence the name hash . When you look at a hash fossil, you actually are looking at a piece of ancient seabed . In hash fossils you can usually find the pieces of coral s, crinoid s, bryzoan s, and brachiopod s. Also you can rarely find a piece of a trilobite . Hash fossils are very common, and are most easily found in storm deposit s. References http www.nysm.nysed.gov virtual collections splendor in stone splendortour23.html New York state museum A Complete Guide To Michigan Fossils by Joseph Khodl Category Fossils ... more details
Infobox cryptographic hash function name SANDstorm image caption General designers Mark Torgerson, Richard Schroeppel, Tim Draelos, Nathan Dautenhahn, Sean Malone, Andrea Walker, Michael Collins, Hilarie Orman, publish date 2008 series derived from derived to related to certification Detail digest size 224, 256, 384, 512 structure rounds cryptanalysis None The SANDstorm hash ref http www.sandia.gov scada documents SANDstorm Submission 2008 10 30.pdf SANDstorm Algorithm Specification ref is a cryptographic hash function designed in 2008 by Mark Torgerson, Richard Schroeppel , Tim Draelos, Nathan Dautenhahn, Sean Malone, Andrea Walker, Michael Collins, and Hilarie Orman for the NIST SHA 3 competition . The SANDstorm hash was accepted into the first round of the NIST hash function competition, but was not accepted into the second round ref http csrc.nist.gov groups ST hash sha 3 Round2 submissions rnd2.html NIST Information on Round 2 ref . References references External links http www.sandia.gov scada documents SANDstorm Submission 2008 10 30.pdf SANDstorm Algorithm Specification http csrc.nist.gov groups ST hash sha 3 Round1 documents SANDstorm.zip SANDStorm Submission Package Crypto navbox hash DEFAULTSORT Sandstorm Hash Category Cryptographic hash functions Category NIST hash function competition ... more details
A hash chain is the successive application of a cryptographic hash function to a piece of data. In computer security , a hash chain is a method to produce many One time password one time keys from a single Key cryptography key or password . For non repudiation a hash function can be applied successively to additional pieces of data in order to record the chronology of data s existence. Definition A hash chain is a successive application of a cryptographic hash function math h x math to a string. For example, math h h h h x math gives a hash chain of length 4, often denoted math h 4 x math Applications main S KEY Leslie Lamport Lamport ref name lamporthash L. Lamport, Password Authentication with Insecure Communication , Communications of the ACM 24.11 November 1981 , pp 770 772. http scholar.google.de scholar?num 100&hl de&lr &cluster 10450198314466995215 http citeseer.ist.psu.edu context 2064887 0 ref suggested the use of hash chains as a password protection scheme in an insecure environment. A server which needs to provide authentication may store a hash chain rather than a plain text password and prevent theft of the password in transmission or theft from the server. For example ... h h 999 password h 1000 password math and verifies this matches the hash chain it has stored. It then stores ... seeing math h 999 password math communicated to the server will be unable to re transmit the same hash ... to the One way function one way property of Cryptographic hash function cryptographically secure hash function s, it is infeasible for the eavesdropper to reverse the hash function and obtain an earlier piece of the hash chain. In this example, the user could authenticate 1000 times before the hash chain is exhausted. Each time the hash value is different, and thus cannot be duplicated by an attacker. See also Challenge response authentication Hash list In contrast to the recursive structure of hash chains, the elements of a hash list are independent of each other. One time password References ... more details
Unreferenced date December 2009 Lowercase title hashhash is a Unix command that prints the location information for the commands found. Syntax ksh hash name Description When the user gives a command, the shell searches for the command in the path specified in the PATH environmental variable and stores the location in the hash. This command can be used to search for the command given. The command is built into the shell. C shell implements this command in a different way. Options The following options are supported name Searches the PATH environmental variable for the name given Exit Status This command returns the following exit values 0 Successful completion 1 An Error occurred Examples 1. hash Print the hash table. 2. hash cat Searches for command cat in the path specified by PATH environmental variable if found, adds it to the hash. See also The Bash Unix shell bash command, C shell csh command, find command, korn shell ksh command, Bourne shell sh command. Category Unix SUS2008 utilities el Hash Unix ... more details
Spectral Hash is a cryptographic hash function submitted to the NIST hash function competition by Gokay Saldaml , Cevahir Demirk ran, Megan Maguire, Carl Minden, Jacob Topper, Alex Troesch, Cody Walker, etin Kaya Ko . ref name NIST submission, 2009 cite web title Spectral Hash url http csrc.nist.gov groups ST hash sha 3 Round1 Feb2009 documents spectral koc.pdf author etin Kaya Ko publisher Computer Security Resource Center, NIST format pdf ref ref name NIST Conference, 2009 cite web title First SHA 3 Candidate Conference date 25 28 February 2009 url http csrc.nist.gov groups ST hash sha 3 Round1 Feb2009 program.html publisher Computer Security Resource Center, NIST ref ref name IEEE, 2009 cite journal title A High Performance Hardware Architecture for Spectral Hash Algorithm pages 215 218 journal 2009 20th IEEE International Conference on Application specific Systems, Architectures and Processors year 2009 url http www.computer.org portal web csdl doi 10.1109 ASAP.2009.31 doi 10.1109 ASAP.2009.31 author Ray C.C. Cheung, etin K. Ko , John D. Villasenor ref It uses a Merkle Damgard construction and employs several mathematical structures including Finite fields and Discrete Fourier transforms. The authors claims 512 bit hashes at 51.2 gigabits per second on a 100 MHz Virtex 4 FPGA. Spectral hash is insecure a method exists to generate arbitrary collisions in the hash state, and therefore in the final hash digest. ref cite web url http ehash.iaik.tugraz.at uploads 4 4b Spectralhash heilman.txt title Collision for Spectral Hash last Heilman first Ethan date 2009 03 12 accessdate 19 May 2009 ref References Reflist External links http cs.ucsb.edu koc shash index.html The Spectral Hash web site Crypto navbox hash Category NIST hash function competition crypto stub ... more details
The Hash join is an example of a Join SQL join algorithm and is used in the implementation of a relational ... which have that value. Hash joins require an equijoin predicate a predicate comparing values from one table with values from the other table using the equals operator . Classic hash join The classic hash join algorithm for an Join SQL Inner join inner join of two relations proceeds as follows first prepare a hash table of the smaller relation. The hash table entries consist of the join attribute and its row. Because the hash table is accessed by applying a hash function to the join attribute, it will be much ... relation. Once the hash table is built, scan the larger relation and find the relevant rows from the smaller relation by looking in the hash table . The first phase is usually called the build phase, while the second is called the probe phase. Similarly, the join relation on which the hash ... math r math in the build input math R math Add math r math to the in memory hash table If the size of the hash table equals the maximum in memory size Scan the probe input math S math , and add matching join tuples to the output relation Reset the hash table Do a final scan of the probe input math ... hash join A better approach is known as the grace hash join , after the GRACE database machine for which ... Tanaka, H. Moto Oka, T. title Application of Hash to Data Base Machine and Its Architecture ... a hash function, and writing these partitions out to disk. The algorithm then loads pairs of partitions into memory, builds a hash table for the smaller partitioned relation, and probes the other relation for matches with the current hash table. Because the partitions were formed by hashing on the join ... the algorithm is recursively applied an additional orthogonal hash function is chosen to hash the large ... during the initial partitioning phase. Hybrid hash join The hybrid hash join algorithm ref cite journal ... month June year 1984 ref is a refinement of the grace hash join which takes advantage of more available ... more details
Other uses Hash mark disambiguation Hash mark Refimprove date July 2007 Hash marks are short lines, running perpendicular to sidelines or sideboards, used to mark locations, primarily in sports. Usage in ice hockey In ice hockey , the hash marks are two pairs of parallel lines on either side of the face off circles in both ends of the rink. Players must remain on their team s side of the hash mark nearest their own goal during a face off until the puck hits the ice. Usage in gridiron football In American football and Canadian football , the hash marks are two rows of lines near the middle of the field that are parallel to the side lines. These small lines about 1 yard long are used to mark each of the 5 yard lines, which go from sideline to sideline. All plays start with the ball on or between the hash marks. That is, if the ball is downed in between a hash mark and the nearest sideline, it must be reset on the hash mark for the next play. Prior to the adoption of hash marks which were first utilized at the NFL Playoff Game, 1932 first NFL playoff game in 1932 , all plays began where the ball was declared dead, including convert extra point attempts. In most forms of professional football, including the National Football League , Canadian Football League , and most forms of indoor American football indoor football , the hash marks are in line with the goal posts , both being 18 feet 6 inches in the NFL and CFL apart. Both high school football and college football have hash marks significantly wider than the goal posts. The college football standard is 40 feet apart the high school standard is one third of the width of the field 53 feet, 4 inches . This Sport Used from 2015 Pan American Games. Category Ice hockey terminology Category American football terminology Category Canadian football terminology icehockey stub Americanfootball stub es Hashmarks pl Hash marks ... more details
Refimprove date January 2008 A hash filter creates a hash sum from data, typically e mail , and compares the sum against other previously defined sums. Depending on the purpose of the filter, the data can then be included or excluded in a function computer science function based on whether it matches an existing sum. For example, when a message is received by an e mail server with a hash filter, the contents of the e mail is converted into a hash sum. If this sum corresponds to the hash sum of another e mail which has been categorized as e mail spam spam , the received e mail is prevented from being delivered. Spammers attempt to evade this by adding random strings to the text content and random pixel changes confetti to image content see image spam . See also Hash buster References http www.ianywhere.com developer product manuals sqlanywhere 1000 en html dbugen10 ug queryopt s bloom.html Hash Filter algorithm SQL Anywhere Server SQL Usage at iAnywhere.com Category Hash functions security software stub ... more details
Hash cakes may refer to Hash browns Cannabis foods disambig Short pages monitor This long comment was added to the page to prevent it from being listed on Special Shortpages. It and the accompanying monitoring template were generated via Template Long comment. Please do not remove the monitor template without removing the comment as well. ... more details
distinguish Hash brownies Original research date November 2009 refimprove date August 2007 File roesti.jpg ... potatoes called R sti is similar in appearance to many modern forms of hash brown potatoes Image Hashbrown potato patty.jpg thumb One form of hash browns involves diced potato scraps from commercial ... Hash browns or hashed browns are a simple potato preparation in which potato pieces are pan frying ..., hash browns or hashed browns can refer to any of these preparations, while in others it may refer to one specific preparation. In parts of the UK, hash browns can mean fried left over mashed potato. Hash browns are a staple breakfast food at diner s in North America, where they are often fried .... In some parts of the United Kingdom , hash browns strictly refer to shredded or riced, pan fried potatoes ... are par cooked before frying . Preparation A chef may prepare hash browns by forming diced potatoes ... . Frozen hash browns are sometimes made into patty form for ease of handling, the compact flat ... is sliced potato version of the hash brown often called American Fries or American Hash Browns , they can ... day potato chip . History According to the Idaho Potato Commission , hash browns may have ... qa who invented hash browns ref Originally, the full name was hashed brown potatoes or hashed browned ... http www.barrypopik.com index.php new york city entry hash browns hash brown potatoes hashed brown potatoes ref The name was gradually shortened to hash brown potatoes ref 1945, H.L. Mencken ref until the most common name had become simply hash browns around 1970. If a dish of hash browned potatoes incorporates chopped meat , leftovers, or other vegetable s it is more commonly referred to as Hash food hash . Tater Tots , one of the first known commercially produced hash browns, were created by Ore ... potato cake in the UK and Ireland Hash food the potatoes and leftovers dish Rappie pie the French ... fzpothab.pdf United States Standards for Grades of Frozen Hash Brown Potatoes PDF Potato dishes ... more details
Refimprove date July 2010 Image Hash table 4 1 1 0 0 1 0 LL.svg thumb 240px right A hash function that maps ... . A hash function is any algorithm or subroutine that maps large data set data sets , called keys, to smaller ... returned by a hash function are called hash values , hash codes , hash sums , checksums or simply hashes . Descriptions Hash functions are mostly used to accelerate table lookup or data comparison tasks ... file computer file , finding similar stretches in nucleic acid DNA sequences, and so on. A hash ... to override equality and hash functions for an object, that if two objects are equal their hash codes must be the same. This is important in order for it to be possible to find an element in a hash table quickly since two of the same element would both hash to the same slot. Some hash functions may map two or more keys to the same hash value, causing a collision computer science collision . Such hash functions try to map the keys to the hash values as evenly as possible because, as Hash Tables fill up, collisions become more frequent. Thus single digit hash values are frequently restricted to 80 ... , volume 3, Sorting and Searching pages 506 542 ref the design of good hash functions is still a topic of active research. Hash functions are related to and often confused with checksum s, check digit ... hash function s. Although these concepts overlap to some extent, each has its own uses and requirements ... fingerprints than of hash values. Hash tables Hash functions are primarily used in hash table s, to quickly ... the headword . Specifically, the hash function is used to map the search key to the hash. The index gives the place where the corresponding record should be stored. Hash tables, in turn, are used to implement ... keys to the same index. Therefore, each slot of a hash table is associated with implicitly or explicitly ... of a hash table is often called a bucket , and hash values are also called bucket indices . Thus, the hash ... for it. Still, in a half full table, a good hash function will typically narrow the search down to only ... more details
A rolling hash is a hash function where the input is hashed in a window that moves through the input. A few hash functions allow a rolling hash to be computed very quickly the new hash value is rapidly calculated given only the old hash value, the old value removed from the window, and the new value added to the window similar to the way a moving average function can be computed much more quickly than other low pass filters. One of the main applications is the Rabin Karp string search algorithm , which uses the rolling hash described below. Another popular application is rsync program which uses a checksum based on Mark Adler s adler 32 as its rolling hash. Rabin Karp rolling hash The Rabin Karp string search algorithm is normally used with a very simple rolling hash function that only uses ... shifter barrel shifts instead. It presumes that there is some hash function math h math from characters to integers in the interval math 0,2 L math . This hash function might be simply an array or a hash ... or . The hash values are defined as math H s k 1 h c 1 oplus s k 2 h c 2 oplus ldots oplus s h c k ... is a number in math 0,2 L math . Computing the hash values in a rolling fashion is done as follows. Let math H math be the previous hash value. Rotate math H math once math H leftarrow s H ... character. Independence At best, rolling hash values are pairwise independent ref name lemirekaser ... Rabin Karp rolling hash values are uniform. Hashing n grams by cyclic polynomials achieves pairwise independence simply keep the first math L n 1 math bits. Computational complexity All rolling hash ... of the window math k math varies. Rabin Karp rolling hash requires the multiplications of two math ... is a Free software C implementation of several rolling hash functions http code.google.com p rollinghashjava rollinghashjava is an Apache licensed Java implementation of rolling hash functions Footnotes references Category Hash functions ... more details
Refimprove date May 2011 File Corn beef hash.jpg thumb An order of corned beef hash with carrots. Hash ... www.hormelfoods.com brands hormel HormelHash.aspx title Hormel Foods Hormel Mary Kitchen hash Varieties ... in excess of that permitted in regular corned beef hash. br br Hormel Corned Beef Hash ... Potatoes, Water, Salt, Sugar, Flavoring, Spice, Sodium Nitrite. br br Hormel Roast Beef Hash Ingredients ... 87542 Food Recipes Corned beef hash . BBC. Retrieved on 2011 04 09. ref In many locations, hash is served primarily as a breakfast food on restaurant menus and as home cuisine, often served with eggs and toast or biscuits , and occasionally fried potatoes hash browns , home fries , etc. . The dish may also use corned beef or roast beef. Corned beef hash became especially popular in some ... 1 . BBC. Retrieved on 2011 04 09. ref United Kingdom In Northern England , corned beef hash is a traditional ... is very similar to hash. There are many variations on the dish, but all consist of a base of mashed ... there are many variations. United States Corned beef hash and roast beef hash were introduced in the U.S. ... Roast Beef Hash Ad publisher Hormel accessdate July 18, 2011 After Hormel Mary Kitchen corned beef hash was on the market, roast beef hash joined the lineup. Other advertisements boasted that Mary Kitchen makes this roast beef hash the way you would fix a special dish for Sunday dinner . A gold lined oven once roasted the beef that helped establish this roast beef hash which is still popular today. ref In the United States, September 27th is National Corned Beef Hash Day. ref http eatocracy.cnn.com 2011 09 27 breakfast buffet national corned beef hash day ref Alternatively, in the Cuisine of the Southern United States southern United States , the term hash may refer to two dishes a Southern ... washpot or hashpot. ref http www.bbq porch.org recipes html r1871.htm South Carolina Hash ref In some ... also use the term hash to refer to meat, such as wild game, that is served as BBQ or Pulled ... more details
Expand Spanish topic culture date March 2009 Arena Hash was a Peru vian Rock music rock Pop music pop band music band . Image Arena has 123.JPG thumb 300px The band members in the 80s. br Above Christian Meier left , Pedro Suarez Vertiz right . br Bottom Arturo Pomar Jr. left , Patricio Suarez Vertiz right . This band originated from the early Paranoia , a band formed at Maria Reina School, a Peruvian school in 1984. Arena Hash became famous in 1988 with their local hit Cuando La Cama Me Da Vueltas . Arena Hash became very popular Citation needed date February 2007 in Peruvian radio . The band broke up in 1993 because their lead singer Pedro Suarez Vertiz began a solo career and became one of the most successful Peruvian rockers Citation needed date February 2007 of the decade. Christian Meier also became a singer and actor in Telenovela s. Possible Return On August 29, 2009, Pedro Suarez Vertiz said to a local Peruvian newspaper ElComercio during an interview that there might be a possibility to revive Arena Hash, he also said that Christian, Patricio and Arturo want to as well. http www.elcomercio.com.pe noticia 348655 pedro suarez vertiz anuncia regreso agrupacion arena hash Members Pedro Suarez Vertiz Singing vocals , guitar Patricio Suarez Vertiz bass guitar bass Christian Meier keyboard instrument keyboards Arturo Pomar Jr. Drum kit drums . Edward Malaga Trillo early support on keyboards and back vocals . Albums Arena Hash album Arena Hash 1987 El Rey Del Ah Ah Ah 1991 El Archivo De Arena Hash 1995 Singles Difamaci n 1986 El Kangrejo 1987 Cuando La Cama Me Da Vueltas 1988 Me Resfri En Brasil 1988 Stress 1988 Materialismo Sexual 1990 El Rey Del Ah Ah A 1991 Y Es Que Sucede As 1991 Como te va Mi Amor 1991 A ese Infierno no voy a Volver 1991 Category Peruvian musical groups peru stub es Arena Hash fr Arena Hash ... more details
In computer science , hash trie can refer to A space efficient implementation of a sparse trie , in which the descendants of each node may be interleaved in memory. The name is suggested by a similarity to a closed hash table . ref name Liang1983 Verify source I believe the source doesn t reference a hash trie , only packed tries and indexed tries date May 2009 An ordinary trie used to store hash function hash values , for example, in an implementation of a hash tree . A data structure which combines features of hash tables and LC tries in order to perform efficient lookups and updates ref name Roshan2004 References references ref name Liang1983 Cite last1 Liang first1 Frank first2 Mark year 1983 month June title Word hy phen a tion by com pu ter publisher Frank M. Liang, Ph.D. thesis, Stanford University. url http www.tug.org docs liang url http www.tug.org docs liang liang thesis.pdf accessdate 2010 03 28 ref ref name Roshan2004 cite last1 Thomas first1 Roshan last2 Mark first2 Brian last3 Johnson first3 Tommy last4 Croall first4 James title High speed Legitimacy based DDoS Packet Filtering with Network Processors A Case Study and Implementation on the Intel IXP1200 url http napl.gmu.edu pubs BookContrib ThomasMarkJC NPW04.pdf accessdate 2009 05 03 year 2004 ref references Category Trees structure ... more details
In computer science , particularly in functional programming , hash consing is a technique used to share values that are structurally equal. The term hash consing originates from implementations of Lisp programming language Lisp ref Cite document first Eiichi last Goto authorlink Eiichi Goto title Monocopy and associative algorithms in extended Lisp place Tokyo publisher University of Tokyo Technical Report TR 74 03 year 1974 ref that attempt to reuse cons cells that have been constructed before, avoiding the penalty of memory allocation . Hash consing is most commonly implemented with hash table s storing Weak reference weak references that may be garbage collection computer science garbage collected when the data stored therein contains no reference computer science reference s from outside the table. ref cite book author Allen, John title Anatomy of Lisp publisher McGraw Hill year 1978 isbn 007001115X ref ref Cite document last1 Fill tre first1 Jean Christophe last2 Conchon first2 Sylvain contribution Type Safe Modular Hash Consing title Workshop on ML publisher Association for Computing Machinery ACM year 2006 ref Hash consing has been shown to give dramatic performance improvements&mdash both space and time&mdash for symbolic computation symbolic and dynamic programming algorithms. fact date March 2009 In other communities a similar idea is known as the Flyweight pattern . When applied to string computer science string s this technique is also known as string interning . Examples Scheme Simple, not very efficient, but suitable for demonstration of the concept implementation of a memoization memoizer by means of hash table and weak references in Scheme source lang scheme weak hashes require hash table define make weak table . args apply make hash table args define weak table set table key data let w hash table ref table key f if w vector set w 0 data let w make weak vector 1 vector set w 0 data hash table set table key w define weak table ref table key let w hash ... more details
Refimprove date January 2008 A hash buster is a Computer program program which randomly adds characters to data for the data s hash sum to be different than if the characters were not added. ref cite web last Delio first Michelle title Random Acts of Spamness url http www.wired.com techbiz it news 2004 01 61886?currentPage all work Wired Tech Biz publisher Wired Magazine accessdate 24 September 2011 ref This is typically used to add words to e mail spam spam e mails, to bypass hash filter s. As the e mail s hash sum is different from the sum of e mails previously defined as spam, the e mail is not considered spam and therefore delivered as if it were a normal message. Hash busters can also be used to randomly add content to any kind of file until the hash sum becomes a certain sum. In e mail context, this could be used to bypass a filter which only accepts e mails with a certain sum. Initially spams containing white noise from hash busters tended to simply exhibit paragraphs of literally random words, but increasingly these are now appearing somewhat grammatical. Interestingly many of the examples appearing around the summer of 2006 or date September 2011 are distorted in ways which render the links to the desired advertising sites unusable, for example substituting 001 for www . This may be a good technique for avoiding a filter, but is disastrous for leading novice users to websites. Additionally much of the embedded HTML code, as well as any MIME encoded attachments, is scrambled and distorted by the process, again decreasing the true effectiveness of the spam. It stands to reason that hand coded spams would not be finalised in this way, so one possible theory is that the newer hash busted spams are being sent by self altering Trojan horse computing trojan horses rather than by human users. It seems that many of these are derived originally from fake replica spam systems or date September 2011 which might give a clue as to the identity of the mutating trojan . There seems ... more details
Orphan date July 2008 Unreferenced date November 2006 Hash is a 2005 comedy film directed by Scott Innes ... Young. The film s central character is Hash McBrown. It is narrated by Stephen Fry . The film itself is a sequel to Innes first film, Bones , in which Hash McBrown appears in four scenes as a narrator ... a Hash McBrown novel. Plot Hash McBrown Dan Smith is a down on his luck bounty hunter and former three time Kiss the Canvas bare knuckle fighting champion. The film starts with Hash midway through apprehending an unknown man, which we are to believe is for the collection on a bounty. Hash is met ..., we are to assume that Hash is victorious in his unspecified number of other matches as he makes ... . Hash is victorious, and in doing so catches the attention of the villainous Black Pudding. Innes ... to Pudding, was responsible for the disfigurement that Pudding has suffered. It is revealed to Hash ... by Salamander as he strived for total dominance of the empire. Hash declines as he has already ... Hash s friend Foxtrot Charlie and brags that only he has the antidote to save him, which he will not give up unless Hash brings back the girl. Hash reluctantly agrees to one last mission, and begins the trek to Salamander s mansion. Upon kidnapping the girlfriemd Hash is horrified to discover that she is Hash s ex, Sandy Beaches Lisa Walker . Hash is then placed in the dilemma of whether ... break up of the Hash Sandy relationship was filmed, although cut from the final production. All the while Mungo and his army are tracking Hash. Mungo s army consists of ex soldier Sgt Lyndon Adam ... TV host and politician Robert Kilroy Silk. These two Goons seem to kidnap Hash s mute, suicidal ... captures Sandy and leaves Hash for dead. It transpires that the poison that was given to Charlie was fatal, and Charlie dies. Pudding used the chance of an antidote to get Hash to do his bidding, when in actuality no such antidote existed. Hash is left broken, having lost both his friends in Charlie ... more details
merge to Ice water separation date June 2011 Orphan date October 2008 Iceolator hash is hashish made using an ice water extraction process. It is based on the principle that the resin glands of the cannabis plant are heavier than water. The cannabis plant material is usually mixed vigorously in the ice and water with a blender to separate the resin glands. These glands will sink to the bottom of the ice water mix, and fall through a very fine screen. The water is squeezed out of the mixture and the resin glands are removed and dried. Iceolator tends to have a very high THC content compared to traditional methods of making hash. See also Cannabis drug Hashish Ice water separation Category Cannabis ... more details
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