Cyclic redundancy check. An error checking mechanism used for verifying data integrity in serial protocols.
Questions tagged [crc]
1120 questions
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votes
2 answers
Java Code for CRC 128 bit
I need to compute a CRC 128 bit checksum for strings extracted from documents.
I am looking around on the internet but cant find any pseudo code or java code.
So anyone can help me?
Thanks for your attention.

Nguyen Trung
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votes
1 answer
Securing Client Server HTTPS Connection
I have a https connection from Client to Server and a malware in client. The malware modifies the message and compromises its integrity. I am using a proxy to check the Integrity of the message after the malware has changed the message and before…

Pavan K
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votes
1 answer
C program to calculate CRC
Goodnight everyone, I´ve been working on this code based on the logic that to obtain a CRC you need to do 2 XOR operations, the first one: result = data ^ generator, then it moves >> bit by bit over the 16 bits and does the XOR over and over again…

Eos
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votes
1 answer
32 bits data_in and CRC7 VHDL code
I would like to check if my code is correct for this
32 bits data_in
7 bits CRC
Please help me check and if possible explain me how does this code works.
library ieee;
use ieee.std_logic_1164.all;
entity CRC7_32 is
port (data_in : in…

user2617652
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votes
1 answer
16 bit Checksum fuzzy analsysis - Leveraging "collisions", biases a thing?
If playing around with CRC RevEng fails, what next? That is the gist of my question. I am trying to learn more how to think for myself, not just looking for an answer 1 time to 1 problem.
Assuming the following:
1.) You have full control of white…

JOULTICOA
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votes
1 answer
CUDA C - CRC32 - Finding unknown polynom and crcxor - program speed up
I was looking for questions related to my problem but only found questions regarding CRC32 reversing. My topic is a bit different.
I am a novice programmer and I have such a task to do. I have input (3 strings of 4 bytes). For this data, I know…

th3r4t3l
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votes
1 answer
How to calculate data buffer to zero checksum value with as little data as it's possible
Given this checksum calculation function in C++
int calcCrcPartial(unsigned short* lpdwBlockData, unsigned short dwBlockSizeInBytes, int iInitialCrc)
{
unsigned short dwBlocksSizeInWords;
int bIsSigned;
signed int j;
signed int i;
…

Boris Jodorovsky
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votes
1 answer
How to adjust the reconcilation factor calculation for a CRC32 to a CRC16?
In my Project i need to append one byte to a data buffer.
If I add this extra byte this would cause a change of the crc checksum.
In order to prevent a change I have to calculate a reconcilation factor which is appended to the end of the data.
The…

Philipp Fu
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votes
2 answers
Delphi CRC16 ModbusRTU
Good day everyone. I am trying to create a software to comunicate modbus devices to my software. I have problem on CRC16 sometimes the device respond sometimes not.
Details below:
function CRC16(Data: AnsiString): AnsiString;
var
i,j,iSum,f :…

Freshman Programmer
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votes
1 answer
Input of CRC when the input is random in matlab
I have this code for CRC code in MATLAB, msg is the data and poly is the generator function.
msg=[1 0 1 1 0 0 1 0 1 ];
poly=[1 0 1 1];
[M, N]=size(poly);
mseg=[msg zeros(1,N-1)];
[q, r]=deconv(mseg,poly);
r=abs(r);
for i=1:length(r)
…

user3637733
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votes
1 answer
what is this 2-byte LRC/VRC checksum?
I am trying to interpret an old (20years) electronic device that sends serial data. The messages are HEX format 22 bytes each. 20 bytes are data (I checked that they change according to specific functions) and the last 2 bytes are somekind of…

ElectronS
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votes
1 answer
Detect faulty physical links with ping
I would have a question regarding physical problem detection in a link with ping.
If we have a fiber or cable which has a problem and generate some CRC errors on the frame (visible with switch or router interface statistics), it's possible all ping…

bdes31
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votes
1 answer
CRC8 with X^8 + X2 + X + 1 Working java source code
I want a working Java source code for calculation of CRC8 byte for Array of bytes.
I tested many, but all of them stop in middle because the index of CRC8 TABLE went Out Of Bounds with this error.
Exception in thread "main"…

DoctorDoom
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votes
1 answer
LTO CM CRC Function
I'm looking for some advice on writing a C function to calculate a 16 bit CRC for an LTO RFID chip.
The spec says:
For commands and data that are protected by the 16-bit CRC, the
generator polynomial shall be G(x) = x16 + x12 + x5 + 1 The CRC…

gazillabyte
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votes
1 answer
I want to convert date time into 6 digit number, then convert it back into the exact date time. Is there a encryption method to this?
Here are what I want do (1) convert date time to 6digit number ;(2)convert the 6digit number to the input date time. Any suggestion to do this?

user3097695
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