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| | Checksum - Wikipedia, the free encyclopedia |
 | | The cost of the ability to detect more types of error is the increased complexity of computing the checksum. | | | The simplest form of checksum, which simply adds up the bytes in the data, cannot detect a number of types of errors. | | | More sophisticated types of redundancy check, including Fletcher's checksum, Adler-32, and cyclic redundancy checks (CRCs), are designed to address these weaknesses by considering not only the value of each byte but also its position. |
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http://en.wikipedia.org/wiki/Checksum
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| | [No title] |
| | For computing the checksum, the checksum field should be zero. |
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http://www.ietf.org/rfc/rfc792.txt
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| | Checksum Task |
| | Specifies the algorithm to be used to compute the checksum. | | | The individual checksums and the relative paths to the files within the filesets they are defined in will be used to compute this checksum. | | | If you are going to use the task to create checksums used in an environment where security is important, please take some time to investigate the algorithms offered by your JCE provider. |
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http://ant.apache.org/manual/CoreTasks/checksum.html
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| | Checksum Algorithm |
| | For example, the simplest checksum is to sum up all the bytes of a transmission, computing the sum in an 8-bit counter. | | | A checksum is a value which is computed which allows you to check the validity of something. | | | A solution to this is to do something like negate the checksum value computed, subtract 1 from it, and expect that the result of the receiver's checksum of the n bytes is 0xFF (-1, as a signed 8-bit value). |
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http://www.flounder.com/checksum.htm
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| | CHECKSUM 1L "19 June 1992" |
| | If the checksum has previously been installed in the input file, and the input file has not been corrupted since then, the output file will be identical to the input file. | | | checksum computes a 16-bit cyclic redundancy checksum (CRC) for a file, as well as counts of the words, lines and characters. | | | checksum is intended to support the reliable exchange of text files between different computers, even ones with different operating systems. |
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http://www.math.utah.edu:8080/ftp/pub/misc/checksum-1-03.html
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| | Cyclic redundancy check - Wikipedia, the free encyclopedia |
| | A cyclic redundancy check (CRC) is a type of hash function used to produce a checksum, which is a small number of bits, from a large block of data, such as a packet of network traffic or a block of a computer file, in order to detect errors in transmission or storage. | | | Alder-32 Note: D is the string of bytes for which the checksum is to be calculated, and n is the length of D. | | | The coefficients of the remainder polynomial are the CRC, and there are simple, efficient algorithms for computing this remainder, such as the one shown below. |
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http://en.wikipedia.org/wiki/Cyclic_redundancy_check
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| | Checksum Classes |
| | The Checksum classes are used to compute checksums for arbitrary binary streams. | | | Checksum computation classes provide MD5 and CRC checksum computation | | | XGCRCChecksum::kCRC16 Causes this object to compute a 16-bit checksum, as used in most applications which compute a 16-bit checksum. |
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http://yaaf.sourceforge.net/docs/quickrefguide/checksum.html
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| | FITS Checksum Proposal |
| | The 1's complement checksum is simple and fast to compute. | | | Other checksums are also options in the binary case, especially if the checksum fields can be located at the end of the file, which simplifies the arithmetic significantly. | | | The checksum does not guard against organized transformations or malicious tampering, however, because simple tranformations, such as rearranging the order of 32-bit words in the file, do not affect the computed checksum value. |
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http://heasarc.gsfc.nasa.gov/docs/heasarc/fits/checksum23may02/checksum23may02.html
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| | Checksum |
| | Good algorithms for computing checksums are not obvious. | | | Of course, no human should have to compute a checksum; that is a job for a computer program. | | | The file must contain the checksum, but somehow, the checksum itself must not be counted when the checksum is computed. |
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http://www.math.utah.edu/~beebe/software/filehdr/node15.html
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| | Pescados Software - checkSum+ |
| | These files store "checksum" information about files, and will allow this and other applications know if the related files are or not corrupted. | | | We also use ed2k_hash (available at SourceForge) to generate the md4 algorithm specific for the mlnet network, and sha2 for all the sha2 algorithms (thanks to Aaron Gifford). | | | If you have a file which you can't process using checkSum+ and you receive a dialog similar to "I can't process this file", then it simply can't be done. |
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http://homepage.mac.com/julifos/soft/checksum
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| | RFC 1146 (rfc1146) - TCP alternate checksum options |
| | Whether the checksum is split between the checksum field in the TCP header and the option or the entire checksum is placed in the option is determined on a checksum by checksum basis. | | | Should the alternate checksum require more than 2 octets to transmit, the checksum may either be moved into a TCP Alternate Checksum Data Option and the checksum field of the TCP header be sent as 0, or the data may be split between the header field and the option. | | | APPENDIX II: The 16-bit Fletcher Checksum Algorithm The 16-bit Fletcher Checksum algorithm proceeds in precisely the same manner as the 8-bit checksum algorithm,, except that A, B and the D[i] are 16-bit quantities. |
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http://www.faqs.org/rfcs/rfc1146.html
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| | CHECKSUM (Transact-SQL Reference (SQL Server)) |
| | BINARY_CHECKSUM and CHECKSUM are similar functions: they can be used to compute a checksum value on a list of expressions, and the order of expressions affects the resultant value. | | | The hash index is built by adding a computed checksum column to the table being indexed, then building an index on the checksum column. | | | Returns the checksum value computed over a row of a table, or over a list of expressions. |
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http://msdn.microsoft.com/library/en-us/tsqlref/ts_ca-co_9p2h.asp?frame=true
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| | [No title] |
| | Suppose a checksum is to be computed over the sequence of octets Braden, Borman, & Partridge [Page 1] RFC 1071 Computing the Internet Checksum September 1988 A, B, C, D,... | | | Before computing the checksum value, the sender places a zero in the checksum field of the packet. | | | This allows the sender to compute the checksum function by placing a zero in the packet checksum field before computing the value. |
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http://www.ietf.org/rfc/rfc1071.txt
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| | RFC 1624 - Computation of the Internet Checksum via Incremental Update. A. Rijsinghani, Ed.. |
| | RFC 1624 Incremental Internet Checksum May 1994 non-zero field in the IP header, and the checksum field in the protocol header is the complement of the sum, the checksum field can never contain ~(+0), which is -0 (0xFFFF). | | | It is recommended that intermediate systems compute incremental checksum using the method described in this document, and end systems verify checksum as per the method described in RFC 1071. | | | RFC 1141 yields an updated header checksum of -0 when it should be +0. |
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http://rfc.sunsite.dk/rfc/rfc1624.html
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| | AccuHash 2.0 - Main - verify accuracy of your files with CRC32, MD5, SHA1 |
| | Checksum calculator is very convenient when necessary to quickly determine the checksum value of specified file, for example, in case the site owner publish checksum values directly on their web pages. | | | AccuHash 2.0 has the integrated Checksum Calculatoran utility function, intended to calculate checksum value of specified file or folder without creating checksum file, which allows to calculate the checksum value for specified file directly, without creating the checksum file. | | | AccuHash 2.0 use the checksum file format based on XML and Unicode-enabled - this allows to easily exchange checksum files between different systems in the different countries, add new algorithms and expand the program features. |
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http://www.accuhash.com
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| | REBOL: Checksum - Function Summary |
| | Generally, a checksum is a number which accompanies data to verify that the data has not changed (did not have errors). | | | The /TCP refinement is used to compute the standard TCP networking checksum. | | | The /Secure refinement creates a binary string result that is cryptographically secure: |
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http://www.rebol.com/docs/words/wchecksum.html
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| | Checksum Transmission |
| | The number of false matches on weak checksums (and hence unnecessary strong checksum calculations) are proportinal to the number of hashes calculated by the client (which is roughly the file size on the client) times the likelyhood of a false match. | | | In practice, this means that 4 bytes of weak checksum is optimal in most cases, but for some smaller files 3 bytes is better. | | | The main content of the control file will be the checksums for blocks of data in the file to be downloaded. |
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http://zsync.moria.org.uk/paper/ch02s03.html
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| | Free Java-Software - Jacksum, a java checksum utility |
| | Jacksum is a free and platform independent software for computing and verifying checksums, CRCs and message digests (known as hash values and fingerprints). | | | -x lowercase hex output for the checksum, it is an alias for | | | To avoid this problem, you must cut off this information from the file, before you calculate a checksum from the file (use grep -v or regular expressions for this task). |
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http://www.jonelo.de/java/jacksum
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| | RSP Software |
| | The dword is sliced in two words and the sum is calculated and mod against 65521, the result value is added to a dword value that is the return value of the computation | | | and generate the same checksum code for small strings that have just a change in the sequence of the string, this mean that Adler32 cannot be used to insure the integrity of strings, so, it cannot be used also to insure the integrity of files from my point of view | | | Security problem regarding the Adler32 checksum (17/Apr/2004 21:14) During the development of the Parallel Port Connection OCX we had the opportunity to stuck with the Adler32 checksum for a while and check the return code for small strings, and it was |
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http://rspsoftware.clic3.net/rspchecksum.htm
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| | Google changed the toolbar checksum algorithm |
| | In June 2004, this checksum algorithm was cracked and the code was released all over the web (see comments about that). | | | As you may know, the Google Toolbar has a built in code (in a DLL) for computing the checksum associated to each URL viewed in the browser. | | | This is the reason why we chose to base our PageRank and Backlinks Analyzer software PR Weaver on the Google toolbar and not on cracked versions of the algorithm. |
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http://www.prweaver.com/blog/2004/09/09/10-toolbar-checksum-algorithm
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| | Fast MD5 checksum utility for Windows. |
| | Our checksum utility is developed for easy processing of a huge number of files and has usable command-line interface. | | | It is a fast algorithm that has been developed by Ron Rivest for digital signature in cryptography, and uses the "avalanche effect". | | | Most often you meet errors like: corrupted downloads from the network, pseudo-readable CD (file is read but can not be executed), CD-R\RW or DVD burned but some files are corrupted. |
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http://www.fastsum.com
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| | EF CheckSum Manager: Checksum generator and verification utility - Download2PC |
| | If you send also a checksum file additionally, the receiver can determine on the basis the checksum whether the received files are OK or not. | | | EF CheckSum Manager is a program designed for the integrity examination of files on the standard formats SFV, MD5 and SHA1. | | | The EF CheckSum Manager is easy to use and much fast, supports the recursive processing of file structures, works up to whole drives. |
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http://download2pc.com/9/104/EF-CheckSum-Manager-545.html
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| | checksum - OneLook Dictionary Search |
| | checksum : Free On-line Dictionary of Computing [home, info] | | | checksum : Dictionary of Computing and Digital Media [home, info] | | | checksum : Computer Telephony & Electronics Dictionary and Glossary [home, info] |
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http://www.onelook.com/cgi-bin/cgiwrap/bware/dofind.cgi?word=checksum
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| | Michael Barr's Embedded Systems Glossary - C |
| | One checksum formula is a simple addition, with overflow ignored, wherein the bytes of the packet are added together into a variable of a fixed size/width (say, 16 bits) as they are sent. | | | A software-development tool that translates high-level language programs into the machine-language instructions that a particular processor can understand and execute. | | | A numerical check value calculated from a larger set of data. |
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http://www.netrino.com/Publications/Glossary/C.html
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| | CMOS checksum errors |
| | Explanation: A checksum is computed as an error-detecting code, to protect the BIOS settings stored in the CMOS memory. | | | Each time the system is booted this number is recomputed and checked against the stored value. | | | Viruses can also affect CMOS settings, and motherboard problems can also affect the stored values. |
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http://www.pcguide.com/ts/x/sys/booterrGBER08-c.html
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| | Distributed Checksum Clearinghouses |
| | The 100,000 mail messages/day threshold is implied by the fact that each DCC client-server operation involves about 100 bytes and a flood of checksums between servers is significantly more than 10,000,000 bytes/day. | | | The counts can be used by SMTP servers and mail user agents to detect and reject or filter spam or unsolicited bulk mail. | | | The idea of the DCC is that if mail recipients could compare the mail they receive, they could recognize unsolicited bulk mail. |
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http://www.rhyolite.com/anti-spam/dcc
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| | SourceForge.net: Project Info - Jacksum |
| | Jacksum is a platform independent utility (written entirely in Java) for computing and verifying checksums, CRCs and hashes (fingerprints) as well as timestamps of files (integrity check). |
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http://sourceforge.net/projects/jacksum
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| | A PAINLESS GUIDE TO CRC ERROR DETECTION ALGORITHMS |
| | this by comparing the transmitted checksum (33) with the computer | | | checksum algorithm, look on pages 440, and 446-448. | | | option to specify whether to reflect the output checksum value. |
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http://www.geocities.com/SiliconValley/Pines/8659/crc.htm
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| | HashCalc - Message Digest, Checksum and HMAC generation ... ... |
| | A fast and easy-to-use calculator that allows to compute message digests, checksums and HMACs for files, as well as for text and hex strings. | | | It supports 3 input data formats: file, text string and hexadecimal string. | | | It offers a choice of 13 of the most popular hash and checksum algorithms for calculations. |
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http://www.slavasoft.com/hashcalc
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| | Checksum Transformation |
| | The Checksum Transformation computes a hash value, the checksum, across one or more columns, returning the result in the Checksum output column. | | | The component has been built using pre-release versions of Microsoft Visual Studio 2005 and Microsoft SQL Server 2005 | | | A user interface is provided, as well as the ability to change the checksum output column name. |
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http://www.sqlis.com/default.aspx?21
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| | ASPN : Python Cookbook : Python Luhn checksum for credit card validation |
| | luhnify = lambda digit: sum(divmod(digit*2, 10)) def luhn_checksum(digits): """Return the Luhn checksum of a sequence of digits. | | | It does not match the other 2 listed here, and it returns "7" for my credit card. | | | """ easy checksum """ def checksum(a): return (10 - sum([int(y)*[7,3,1][x%3] for x, y in enumerate(str(a)[::-1])])%10)%10 |
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http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/172845
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| | Checksum 1.0 - MacUpdate |
| | You can drag-and-drop files onto the window to calculate checksums. | | | This is a Cocoa wrapper around the OpenSSL command line tool. | | | Add Checksum to your Watch List (member feature) |
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http://www.macupdate.com/info.php/id/13976
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| | Red Hat Network - About RHN - Get RHN Software |
| | An MD5 checksum is designed to verify that the file on your system is identical to the file provided by RHN. | | | Download the appropriate packages for your distribution, listed below. | | | Next to the link, you will find the MD5 checksum for the file. |
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http://rhn.redhat.com/help/latest-up2date.pxt
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| | Information Security Glossary - Checksum |
| | Checksum is a technique whereby the individual binary values of a string of storage locations on your computer are totalled, and the total retained for future reference. | | | On subsequent accesses, the summing procedure is repeated, and the total compared to that derived previously. | | | Risk Associates: Resources for Security Risk Analysis, ISO 17799 / BS7799, Security Policies and Security Audit |
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http://www.yourwindow.to/information-security/gl_checksum.htm
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| | 6.4.1. The CRC-32 Checksum (crc32) |
| | The use of collision-proof checksums is recommended for environments where such attacks represent a significant threat. | | | The CRC-32 checksum calculates a checksum based on a cyclic redundancy check as described in ISO 3309 [14]. | | | An attacker using a probabilistic chosen-plaintext attack as described in [13] might be able to generate an alternative message that satisfies the checksum. |
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http://www.freesoft.org/CIE/RFC/1510/78.htm
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| | Pescados Software - homepage of MacHacha, mpc2aiff, etc... |
| | checkSum+ 1.3b2 fixes some bugs with large md5summer files. | | | We improved again checkSum+ 1.2, which fixes some bugs, improves some behaviours and introduces new features. | | | 1.2b1 adds several checksum calculations for the explorer window, and introduces a new preference to show such window by default, on launch. |
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http://homepage.mac.com/julifos/soft
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| | OpenSSH trojaned! |
| | main openBSD (ftp.openbsd.org) mirror was compromised, after developers noticed that the checksum of the package had changed. | | | The malicious code is not particularly sophisticated but it is a remotely controllable program that could give potential attackers root access to victim's machines. | | | Overnight it was realised that the tarball for OpenSSH 3.4p1 on the |
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http://online.securityfocus.com/news/560
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| | What's an ISBN, a UPC, and a checksum |
| | A checksum is a digit that is the product of a series of mathematical operations on the first digits that help doublecheck that the other digits are correctly entered into a system when typed manually or barcode scanned. | | | The checksum for ISBNs is base 11, meaning that it can be a number from 0 to 10. | | | A UPC is a Universal Product Code, which is used in bar code format on all manner of goods for sale. |
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http://www.isbn.nu/whatsanisbn.html
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| | CheckSum Low Cost In-Circuit Test - Home |
| | MultiWriter ISP device programming system, multiplies throughput--especially for multi-board panels--while it saves you money. | | | CheckSum Analyst Low Cost ICT equipped wih TestJet technology is a better way to test ICs on boards. | | | All information at this site is Copyright 1995-2005 by CheckSum LLC. |
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http://www.checksum.com
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| | Definition: checksum |
| | Note 2: The checksum is calculated by treating the data items as numeric values. | | | Note 3: Checksums are used in error detecting and correcting. | | | Note: Checksums are stored or transmitted with data and are intended to detect data integrity problems. |
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http://www.its.bldrdoc.gov/fs-1037/dir-007/_0950.htm
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| | [No title] |
| | This is a port of a C function that did a 32bit, 2's complement checksum. | | | trunc(length(p_buff'x')/2) loop l_n := ascii(substr(p_buff'x', 1+(i-1)*2, 1))*256 + ascii(substr(p_buff'x', 2+(i-1)*2, 1)); l_sum := mod(l_sum+l_n,4294967296); end loop; while (l_sum > 65536) loop l_sum := bitand(l_sum, 65535) + trunc(l_sum/65536); end loop; return l_sum; end checksum; |
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http://www.oracledba.co.uk/tips/checksum_plsql.htm
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| | checksum - a Whatis.com definition |
| | A checksum is a count of the number of bits in a transmission unit that is included with the unit so that the receiver can check to see whether the same number of bits arrived. | | | Find white papers, products and vendors related to checksum. | | | If the counts match, it's assumed that the complete transmission was received. |
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http://searchsecurity.techtarget.com/sDefinition/0,,sid14_gci211779,00.html
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