XOR may mean Exclusive or logic XOR cipher , an encryption algorithm XOR gate XOR video game XOR video game x86 instruction listings XOR , an x86 instruction disambig cs XOR es XOR eo XOR fr XOR homonymie it XOR hu XOR egy rtelm s t lap ro XOR sk XOR ... more details
About XOR in the sense of an electronic logic gate e.g. CMOS 4030 XOR in the purely logical sense Exclusive disjunction other uses XOR disambiguation class wikitable align right bgcolor ddeeff align center colspan 2 INPUT br A B OUTPUT br A XOR B bgcolor ddffdd align center 0 0 0 bgcolor ddffdd align center 0 1 1 bgcolor ddffdd align center 1 0 1 bgcolor ddffdd align center 1 1 0 The XOR gate ... output 0 results. A way to remember XOR is one or the other but not both . It represents the inequality ... 0 . This function is addition modulo 2. As a result, XOR gates are used to implement binary addition in computers. A half adder consists of an XOR gate and an AND gate . Clear Symbols There are two symbols for XOR gates the military symbol which was originally developed in America and the rectangular ... Symbols . Image XOR ANSI.svg thumb 128px left ANSI Military XOR Symbol Image XOR IEC.svg frame left IEC Rectangular XOR Symbol Clear The XOR gate with inputs A and B implements the logical expression math A cdot overline B overline A cdot B math . Hardware description and pinout XOR gates are basic ... XOR gates. The 4070 replaces the less reliable 4030, but keeps the pinout. The pinout diagram is as follows ... Gate Logic Wiring An XOR gate can be constructed using MOSFET s. Here is a diagram of the transmission gate implementation of an XOR Gate. ref name Falstad http www.falstad.com circuit Paul Falstad ... of an XOR gate Alternatives If a specific type of gate is not available, it can be constructed from other available gates. An XOR gate can be trivially constructed from an XNOR gate followed by a NOT gate ... an XOR gate directly using AND, OR and NOT gates. However, this approach requires five gates of three different kinds. An XOR gate can be made from four NAND or five NOR gates in the configurations ... 1em auto 1em auto image XOR from NAND.svg frame right XOR gate constructed using only NAND gates. image XOR from NOR.svg frame right XOR gate constructed using only NOR gates. br clear both More than ... more details
Unreferenced date July 2009 In cryptography , the simple XOR cipher is a simple encryption algorithm that operates according to the principles A math oplus math 0 A, A math oplus math A 0, A math oplus math B math oplus math C A math oplus math B math oplus math C , B math oplus math A math oplus math A B math oplus math 0 B, where math oplus math denotes the exclusive disjunction XOR operation. With this logic, a string of text can be encrypted by applying the bitwise XOR operator to every character using a given key. To decrypt the output, merely reapplying the key will remove the cipher. For example, the string Wiki 01010111 01101001 01101011 01101001 in 8 bit ASCII can be encrypted with the key 11110011 as follows tt 01010111 01101001 01101011 01101001 tt math oplus math tt 11110011 11110011 11110011 11110011 tt style border top 1px solid black tt 10100100 10011010 10011000 10011010 tt And conversely, for decryption tt 10100100 10011010 10011000 10011010 tt math oplus math tt 11110011 11110011 11110011 11110011 tt style border top 1px solid black tt 01010111 01101001 01101011 01101001 tt The XOR operator is extremely common as a component in more complex ciphers. By itself, using a constant repeating key, a simple XOR cipher can trivially be broken using frequency analysis . If the content of any message can be guessed or otherwise known then the key can be revealed. Its primary merit is that it is simple to implement, and that the XOR operation is computationally inexpensive. A simple repeating XOR cipher is therefore sometimes used for hiding information in cases where ... repeats , the XOR cipher is more secure. When the keystream is generated by a pseudo random number generator ..., the XOR operator is vulnerable to a known plaintext attack , since plaintext math oplus math ciphertext key . See also Vernam cipher Vigen re cipher External links https chris.dod.net xor xor.php Solving the Basic XOR Cipher Category Stream ciphers es Cifrado XOR sl XOR ifriranje uk XOR zh ... more details
Image XOR Swap.svg thumb upright 2 alt With three XOR operations the binary values 1010 and 0011 are exchanged between variables. Using the XOR swap algorithm to exchange nibble s between variables without the use of temporary storage In computer programming , the XOR swap is an algorithm that uses the exclusive disjunction XOR bitwise operation to swap computer science swap values of distinct variable ... variable. Using the XOR swap algorithm, however, no temporary storage is needed. The algorithm is as follows X X XOR Y Y X XOR Y X X XOR Y The algorithm typically corresponds to three machine code instructions. Since XOR is a commutative operation , X XOR Y can be replaced with Y XOR X in any of the lines ... stored in that location will be zeroed out by the first XOR instruction, and then remain zero ... operation XOR over bit strings of length math N math exhibits the following properties where math oplus math denotes XOR ref The first three properties, along with the existence of an inverse for each element, are the definition of an Abelian group . The last property is a structural feature of XOR ... Register 2 Reduction 0 Initial value math A math math B math 1 code R1 R1 XOR R2 code math A oplus B math math B math 2 code R2 R1 XOR R2 code math A oplus B math math begin align A oplus B oplus B & A oplus B oplus B & A oplus 0 & A end align math L2 br L4 br L3 3 code R1 R1 XOR R2 code math begin ... A math L1 br L2 br L4 br L3 Code example A C programming language C function that implements the XOR ... situations in which XOR swapping may be practical include On a processor where the instruction set encoding permits the XOR swap to be encoded in a smaller number of bytes In a region with high ... do not generate XOR swap code. Reasons for avoidance in practice Most modern compilers can optimize ... of memory and the same number of registers as the XOR swap and is at least as fast, and often faster. The XOR swap is also much less readable, and can be completely opaque to anyone who isn t already ... more details
Refimprove date October 2009 XOR linked lists are a data structure used in computer programming . They take advantage of the bitwise exclusive disjunction XOR operation, here denoted by , to decrease storage ... C D E ... next next next prev prev prev code An XOR linked list compresses the same information into one address field by storing the bitwise XOR of the address for previous and the address for next ... supposing you are at C, you can take the address of the previous item, B, and XOR it with the value .... This form of linked list may be inadvisable General purpose debugging tools cannot follow the XOR ... structures that do not contain literal pointer computing pointer s XOR of pointers is not defined ... the addresses of the other elements of the list. Two XOR operations suffice to do the traversal ... of the current say C list item and a work register containing the XOR of the current address ... is needed in the above sequence after the two XOR operations to detect a zero result in developing ... pointer be zero. A zero pointer is a mirror . The XOR of the left and right neighbor addresses, being the same, is zero. Why does it work? The key is the first operation, and the properties of XOR X X 0 X 0 X X Y Y X X Y Z X Y Z The R2 register always contains the XOR of the address of current item C with the address of the predecessor item P C P. The Link fields in the records contain the XOR of the left and right successor addresses, say L R. XOR of R2 C P with the current link field L R yields ... R, the P R and R cancel, leaving C L. In each case, the result is the XOR of the current address with the next address. XOR of this with the current address in R1 leaves the next address. R2 is left with the requisite XOR pair of the now current address and the predecessor. Variations The underlying principle of the XOR linked list can be applied to any reversible binary operation. Replacing XOR ... as the XOR linked list, except that a zero link field is not a mirror . The address of the next ... more details
Infobox VG title XOR image caption developer Astral Software publisher Logotron Ltd designer engine released 1987 genre Puzzle game modes Single player ratings platforms ZX Spectrum , Commodore 64 , Amstrad CPC , Amiga , Atari ST , Acorn Electron , BBC Micro media Floppy disk , audio cassette requirements input Computer keyboard, joystick XOR is a computer puzzle game created by Astral Software and published by Logotron in 1987 for a range of platforms including the Acorn Electron , Amiga , Amstrad CPC , Atari ST , BBC Micro , Commodore 64 , and ZX Spectrum . It has since been remade for platforms including Microsoft Windows Windows , Apple Macintosh , RISC OS and Game Boy Advance . XOR is a pure puzzle game with no random or arcade elements, as summed up by the blurb on Logotron s original extensive advertising campaign There are no random events in XOR s labyrinthine palace, and there is no premium on hand eye coordination . You have all the time in the world to work out the precise nature ... of the XOR experience. And XOR is not simply about finding solutions. If you can solve the entire puzzle 15 levels plus an encrypted anagram , you qualify to be a member of the Order of XOR. Gameplay ... fish left or right, and chickens up and down. Bombs There are two types of bomb s in XOR V bombs .... External links http xor.ovine.net Windows remake by Ovine by Design http www.rvvz.demon.nl xor JavaScript version by Rob Veldhuyzen van Zanten http www.gbagames.dsl.pipex.com xor home.htm Game Boy Advance remake by Mick Waites http www.danceswithferrets.org xor index.htm XOR information site including RISC OS version for download. WoS game id 0005800 name XOR http www.jwm art.net light.php?p ..., a XOR like game for Linux using SDL also implementing XOR . http www.level7.org.uk chroma others.html Chroma , an accurate conversion of XOR for both Windows and Linux Category 1987 video games Category ... Category ZX Spectrum games ro XOR joc ... more details
A three layer Perceptron net capable of calculating XOR . The numbers within the perceptrons represent each perceptrons explicit threshold. The numbers that annotate arrows represent the weight of the inputs. This net assumes that if the treshhold is not reached, zero not 1 is output. Note that the bottom layer of inputs is not always considered a real perceptron layer PD self date October 2006 I created it myself with MS Visio. Email me if you want the VSD Category Neural networks ... more details
see also RAID What is RAID Parity? A Parity Drive is a hard drive used in a RAID array to provide fault tolerance . For example, RAID 3 uses a parity drive to create a system that is both fault tolerant and, because of data striping , fast. ref http computer.yourdictionary.com raid Definitions of RAID configurations Retrieved on 2010 11 15 ref One way to implement a parity drive in a RAID array is to use the exclusive or , or XOR, function. XOR is a Boolean logic function which means one or the other, but not both . The XOR of all of the data drives in the RAID array is written to the parity drive. If one of the data drives fails, the XOR of the remaining drives is identical to the data of the lost drive. Therefore, the when a drive is lost, recovering the drive is as simple as copying the XOR of the remaining drives to a fresh data drive. References Reflist Category RAID Compu hardware stub ... more details
logo fur Website http www.lax660.com Article KXOR AM Purpose infobox Licensing Non free logo Category Radio stations in Oregon XOR Category Radio station logos ... more details
contains the ASCII string 1000.00 . He can change that to 9500.00 by xor ing that portion of the ciphertext with the string 1000.00 xor 9500.00 . To see how this works, consider that the cipher text we send is just C K xor 1000.00 . What he is creating is C K xor 1000.00 xor 1000.00 xor 9500.00 C K xor 9500.00 which is what our ciphertext would have been if 9500 were the correct amount ... more details
Summary Information Description Diagram comparing Controlled NOT gate CNOT gate on left and XOR gate on right . Source Own work Image Cnotxor.PNG Image XOR ANSI.svg Date 21 August 2008 Author User Alksentrs Permission GNU FDL other versions Image Cnotxor.PNG original PNG Licensing GFDL migration relicense ... more details
B B B N, and so on. All levels of recovery except the final one use an LDPC, which works by xor exclusive or . Xor operates on binary values, 1s and 0s. A xor B is 1 if A and B have different values and 0 if A and B have the same values. If you are given A xor B and A, you can determine the value for B. A xor B xor A B Similarly, if you are given A xor B and B, you can determine the value for A. This extends to multiple values, so given A xor B xor C xor D and any 3 of the values, the missing value can be recovered. So the recovery blocks in level one are just the xor of some set of input blocks. Similarly, the recovery blocks in level two are each the xor of some set of blocks in level one. The blocks used in the xor are chosen randomly, without repetition. However, the number of blocks xor ed to make a recovery block is chosen from a very specific distribution for each level. Since xor is a fast operation and the recovery blocks are an xor of only a subset of the blocks in the input ... is less than the present blocks in the final level. Going lower, the LDPC xor recovery level can be used ... level. Then the xor of the recovery block with all of the blocks that are present is equal to the missing ... more details
PPRM may refer to Algebraic normal form Positive Polarity Reed Muller representation of a boolean function as a single algebraic sum xor of one or more conjunctions of one or more literals Greater Romania Party it would be nice to know why is this disambig ... more details
Vernam cipher patent , Figure 1. This drawing shows Gilbert Vernam s original concept for a teletype encryption machine that combines plaintext characters C with characters on a key cryptography key paper tape D using an XOR function. The XOR takes place at relays 19 through 25 . If both the C and D contacts are open, no voltage is applied to the relay coil. If both C and D contacts are closed, voltage is applied to both ends of the relay coil, so the relay contacts stay open. If just one of contacts C and D are closed, current flows through the relay coil, closing its contact. PD US patent ... more details
Unreferenced auto yes date December 2009 Orphan date August 2006 att June 2008 Cover coding is a technique for obscuring the data that is transmitted over an insecure link, to reduce the risks of snooping. An example of cover coding would be for the sender to perform a bitwise Exclusive or XOR exclusive OR of the original data with a password or random number which is known to both sender and receiver. The resulting cover coded data is then transmitted from sender to the receiver, who uncovers the original data by performing a further bitwise Exclusive or XOR exclusive OR operation on the received data using the same password or random number. DEFAULTSORT Cover Coding Category Cryptography crypto stub ... more details
A Raid Processing Unit is an Integrated Circuit designed to implement RAID for persistent storage devices. The RPU performs calculations, such as XOR , to maintain data integrity over all connected drives in an array. RAID calculations can be performed by the computer s central processing unit CPU , but using a separate specialized chip for this task can save much array built time and increases overall usage performance. RPU s are used mainly on specialized RAID adapters. Such a RAID adapter acts as an intermediary between the array of inexpensive drives and the computers main data interface such as Conventional PCI PCI , ISA or PCI Express Most RAID adapter use a general purpose Integrated Circuit to perform array built calculations and RAID calculations. Those integrated circuits usually have a good performing XOR unit s . XOR calculations are used to compute data blocks on more advanced RAID levels like RAID 5 and RAID 6 when writing data to the persistent storage devices. Category RAID Compu hardware stub ... more details
mathematics product . The XOR is an 8 bit operation that modifies only the lower 8 bits ... hash by only the order in which the multiply and XOR is performed ref http www.isthe.com chongo tech ... to be hashed hash hash XOR octet of data hash hash math times math FNV prime return hash The above ... more details
Portal Cryptography A reciprocal cipher means, just as one enters the plaintext into the cryptography system to get the ciphertext , one could enter the ciphertext into the same place in the system to get the plaintext. Sometimes also referred as self reciprocal cipher. Examples of reciprocal ciphers are Beaufort cipher Enigma machine ROT13 XOR cipher Categories Category Ciphers Crypto stub zh ... more details
. XOR tag routing In XOR tag routing, switch settings are based on source PE XOR destination PE . This XOR ... source and destination have in common. The most significant bit of the XOR tag is used to select ..., if PE 001 wishes to send a message to PE 010, the XOR tag will be 011 and the appropriate switch ... more details
File Domino Logic Gates.svg thumb The two domino logic gates, from which all others can be built. The XOR gate is dependent on timing. A domino computer is a mechanical computer built using dominoes ref name domcom http everything2.com index.pl?node id 1764437 Domino computer ref to represent mechanical Operational amplifier amplification or Logic gate logic gating of digital signal s. Because of the existence of multiple schemes, domino computer will be used in this article as a collective noun, denoting any particular scheme that uses the mentioned base phenomenon of domino sequences for building machines equivalent to a computer. This choice of terminology may be somewhat arbitrary, because only few resources write on this topic. ref name comdomcon http www.pinkandaint.com oldhome comp dominoes index.html Domino computers , a detailed description written by http www.pinkandaint.com David Johnston ref Basic phenomenon Sequences of standing dominoes so that each topples the next one can be arranged to demonstrate digital concepts such as amplifier amplification and digital signal s. It is some digital information that is conducted by a string of dominoes, thus this effect differs from Phenomenon phenomena where energy is conducted without amplification , thus it dissipates or where amplification is applied to non digital signals, thus noise effects occur. The Domino Day event shows many constructs, mainly with purpose of entertainment. Some constructs may remind people of digital circuit s. Some of them suggest that not only telegraph like tools can be shown, but also simple information processing modules can be built. It is possible to use this phenomenon for constructing unconventional computing tools. ref name domcom ref name comdomcon ref name moldom James Maguire http ... synapse s. Logic Elements The two logic gates XOR and OR are the easiest to make with dominoes. All other gates can be built from these A XOR 1 and A OR B XOR A XOR B A AND B . The XOR gate shown here ... more details
Unreferenced date November 2008 align right image Data Strobe Encoding.png small Data strobe encoding and recovered clock. small Data strobe encoding or D S encoding is an encoding scheme for transmitting data in digital circuit s. It uses two signal lines e.g. wires in a cable or traces on a printed circuit board , Data and Strobe . These have the property that either Data or Strobe changes its Truth value logical value in one clock cycle , but never both. This allows for easy clock recovery with a good jitter tolerance by XOR ing the two signal line values. There is an equivalent way to specify the relationship between Data and Strobe. For even numbered Data bits, Strobe is the opposite of Data. For odd numbered Data bits, Strobe is the same as Data. From this definition it is more obvious that the XOR of Data and Strobe will yield a clock signal. Also, it specifies the simplest means of generating the Strobe signal for a given Data stream. Data strobe encoding originated in IEEE 1355 Standard and is used on the signal lines in SpaceWire and the FireWire IEEE 1394 also known as FireWire 400 system. Gray code is another code that always changes one logical value, but never more than one. Category Line codes telecomm stub ... more details
Unreferenced date December 2009 In cryptography , residual block termination is a variation of cipher block chaining mode CBC that does not require any Padding cryptography padding . It does this by effectively changing to cipher feedback mode for one block. The cost is the increased complexity. Encryption procedure If the plaintext length N is not a multiple of the block size cryptography block size L Encrypt the N L full blocks of plaintext using the cipher block chaining block cipher modes of operation mode Encrypt the last full encrypted block again XOR the remaining bits of the plaintext with leftmost bits of the re encrypted block. Decryption procedure Decrypt the N L full encrypted blocks using the Cipher Block Chaining mode Encrypt the last full encrypted block XOR the remaining bits of the ciphertext with leftmost bits of the re encrypted block. Proof that this decryption procedure really is the inverse of the encryption procedure is left as an exercise for the reader. Short message For messages shorter than one Block size cryptography block , residual block termination can use an encrypted Initialization vector IV instead of the previously encrypted block. Crypto navbox block DEFAULTSORT Residual Block Termination Category Cryptographic algorithms ... more details
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