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Questions tagged [checksum]

A checksum or hash sum is a fixed-size datum computed from an arbitrary block of digital data for the purpose of detecting accidental errors that may have been introduced during its transmission or storage. The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one.

A checksum or hash sum is a fixed-size datum computed from an arbitrary block of digital data for the purpose of detecting accidental errors that may have been introduced during its transmission or storage.

The integrity of the data can be checked at any later time by recomputing the checksum and comparing it with the stored one. This process doesn't guarentee the data hasn't been corrupted, but is a good indication.

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How to properly use malloc function in arm assembly for opening files?

I am working on a school project that is in arm assembly using the raspberry pi. My goal is to open a input file and calculate the checksum just by counting the ASCII character in the input file. Then open a output file that will write the same…
fsociety
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How to find the checksum of a row of "Hex" cells in VBA

I have 14 cells that contain Hex values - I need a way of calculating the checksum of these values. I know the idea is to convert all to decimal and add, then to convert to binary and inverse then plus 1 then convert to hex again - However I am…
Adam
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Calculating checksum for hex words in VBA

I'm currently looking at a spreadsheet with a list of N hexadecimal words and a checksum to verify them. The checksum is just the two's complement of the total - that is, the sum of all of the words, inverted, + 0b1. I'm not sure of the easiest way…
jimbo
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How to do the checksum of files in aix, when sending files to sftp and alos downloding from sftp

** I have written a scripts to find files continuous in all folder and send files to sftp and similarly wise a versa.But Now is want to do checksum of file and ensure that file is transfer to sftp properly.I tried the cksum as my OS is AIX but…
user1376290
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Generating 4 bytes checksum from python bytes-str

I'm setting up a uart communication with a device, but I can't figure out how to generate the four bytes checksum that is required to validate the data I'm sending. In the instrument manual says that the checksum is "a 32-bit unsigned value that…
Gabriel Gardin
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MD5 Encoding HTML Giving 2 Different Results

Can someone help explain why this is happening? If I scrape HTML from a site using the requests module and use hashlib to get the md5 checksum I get one answer. Then if I save the html as an html file, open it, and do the same md5 checksum it gives…
MatthewExpungement
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Calculate CRC 16 X25 in PHP

I'm trying to figure out the checksum for certain messages, but I can not even get the github files from this link https://github.com/meetanthony/crcphp. In the site of the link above works, but when I run a test, no one was able to run the calc for…
Wellington Alves
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Translating messages from device to LIS via ASCII using checksums

I'm looking for some help please. I'm trying to communicate to a device over TCP / IP using ASCII. The protocol includes a checksum that consists of two ASCII characters that represent a two character hexadecimal number in the range 00 through FF. I…
Joe.Duffyy
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Fast and robust checksum algo for a small data file (~10KB)

I have a data file that needs to be pushed to an embedded device. The typical size for the file ranges from a few bytes to about 10K max. My intention is to detect tampering with the contents of this file(chksum to be last element in the data file).…
Zakir
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Trouble Understanding a Checksum Algorithm

Protocol for BM62 Bluetooth Module I just have a simple question about how the Checksum algorithm works for a particular Bluetooth module (BM62). The picture above has the UART protocol explained, and it explains the checksum rule, but I am having…
Bobo
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Fixing checksum issues on intel HEX files

I have made the following intel hex file snippet to test with a couple 8051 processor simulators: :1000F5007002501F500CED2562FDEE3561FEEF35A7 :1001050060FFE56233F562E56133F561E56033F57E One I used is located here: http://www.jroweb.de/8051/ From my…
Mike -- No longer here
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EqualityComparer with stable HashCode and option to ignore diacritics?

I'm looking for a IEqualityComparer that supports stable HashCode, ie the same HashCode between executions/processes. I also need it to ignore casing and nonspacing combining characters (such as diacritics). Are there any "easy" ways of…
Andreas Zita
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flyway version mistmatch after restore backup from another PC

I made database backup from our QA environment and restored it locally. Then I try to start application locally. It leads to error that describes that version mistmatch. Looks like checksum calculates differently for different environments. Is it…
gstackoverflow
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CRC Arduino - Simple implementation for Sanity test

I'm sending command and parameters from one arduino board to another one. I want to validate whether the data has been corrupted or not at the other end. I'm looking for a basic sanity validation. My packet looks like struct Command { uint8_t…
anz
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Is IP header checksum a full proof method of error detection?

While going through IP header checksum i.e. 1's complement of 1's complement sum of 16 bits data, I can't help but think that how come this method can detect error/alteration in data. For example, computer A sends a packet with data (12 and 7) and…
NeilB
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