A checksum is a value created from a binary file that can be used to validate its authenticity and integrity. An example of a checksum is MD4, MD5 and SHA-1.

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how to verify whether a compressed .gz is corrupted or not?

I have many gz downloaded from the internet, and I would like to make sure they are not corrupted. Does the fact that I can open the archive with winzip on windows proves that everything is fine? I ...
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What are these Google SHA1 images? [closed]

If you look at this page you'll see an monochrome image. Above it says Tip: Use the SHA1 checksum shown to verify file integrity. However, I don't know if that's related. What are these ...
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File copy program that generates checksums of the data while copying too

My question in short: is there a tool that copies a file from directory A to B while, simultaneously, generating the checksum of the file it has copied/read, without doing an extra read/pass just to ...
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14 views

How to batch delete files based on their checksum matching an existing list of checksums

I'm looking for a means of deleting files based on their checksum matching a list of previously seen checksums in a text file or some other list. The context is a large photo organization project ...
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35 views

What is the exact meaning of the QuickSFV comments at the end of an SFV file?

What are the QuickSFV comments at the end of an SFV file based on? 25-Monty_Python-The_End-EOS.mp3 D387716E ;Q1-1c11727069c13b6 ;Q1-///4AA== In version 2 it had a line more: ...
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18 views

Verify integrity of a file BEFORE rsync (preventing propagation of bit-rot)

I've got some ideas on how I could craft something together myself using Python and a utility like hashdeep to do this, but I'm willing to bet I'm not the first person that needed to solve this ...
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1answer
48 views

Shell script, AppleScript Mac OS X

I’m trying to copy embedded metadata from image files and write to a .txt file, as well as generate MD5 and SHA1 checksums for the same images to be added to the same .txt file. I can run this ...
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1answer
235 views

Checksums don't match is that bad?

I recently started looking at VisualStudio 2012. I tried downloading it from the official Microsoft link but it failed with some errors. As of some suggestions I downloaded the DVD5 ISO image to ...
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465 views

Unable to update Bios in Lenovo T61 due to damaged battery - What is the way to bypass this issue?

I would like to update bios on my T61 but unfortunately battery died back in the stone age. The whole notebook is a Dual core T7100 1.8 Ghz Centrino Duo without Nvidia graphic card (it has intel ...
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2answers
56 views

Find/check redundant files for cleanup and backup purposes

Very often I want to find out if the contents of given folders match or if the content of a single folder is redundant - maybe to check if it's duplicate and can be removed or to make sure there are ...
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2answers
83 views

calculate checksum of every file that is being written to HDD

Is it possible to automatically calculate checksum of every file that is being written to HDD? My OS is Linux. I've read that btrfs stores some kind of checksums for files. Would be possible to dump ...
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1answer
2k views

How does one verify the PGP RSA and/or DSA checksum signatures for putty?

To verify the download integrity of putty, how is the best way to first verify the "SHA-512: (RSA sig) | (DSA sig)" PGP signature of these check-sum files for putty? (I am guessing "sig" means ...
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5answers
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Does recompiling a program produce a bit-for-bit identical binary?

If I were to compile a program into a single binary, make a checksum, and then recompile it on the same machine with the same compiler and compiler settings and checksum the recompiled program, would ...
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1answer
23 views

prevent file copying not via permissions

Is there any way I can prevent a file from being copied? I don't mean via the file system, but I mean by somthing that must change if the file was copied, like some sum or timestamp My goal is to ...
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votes
1answer
73 views

Computing a checksum of a huge file (30 GB)

I have a huge data set consisting of several files, with size of some of the files exceeding 30 GB. After compressing, transferring the data set over the network, and decompressing again I am ...
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4answers
4k views

Single unix command to correctly transfer a large file?

I am trying to transfer a large (~3GB) file between two unix machines. I can use scp or rsync, but sometimes the transfer is corrupted. (I have to check manually.) I can split the file into pieces ...
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1answer
150 views

What defines a CMOS checksum in a BIOS system?

I am sure that many of you have seen and experienced the dreaded "CMOS checksum error" first hand. But what is it? CMOS Checksum error What is it a checksum of? The entire content of the CMOS ...
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3answers
3k views

How does a downloaded ISO get corrupted? [duplicate]

Possible Duplicate: Is it possible to get corrupted download with http? I downloaded an ISO for fedora. Went to install it as a VM. It failed 5 times the installer. The warning for the ...
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1answer
1k views

Rename files by md5 checksum [closed]

What program can I use to rename files with their calculated md5 checksums? GUI or CLI Programs for Linux or Windows or scripts for DOS or the Linux terminal.
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1answer
401 views

Why do repeated downloads for Google Chrome setup have each time different hashes?

I've tried downloading the setup files for a standalone offline installation version several times in rapid succession. Each next file has an identical size but a different hash. Why is that? Do they ...
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5answers
1k views

Do we really need to check the integrity of downloaded files? [duplicate]

I downloaded a huge amount of files, but discovered the use of md5 and sha as integrity checkers quite recently. From then I always prefer to check it for big downloaded files, even if I never found ...
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1answer
136 views

Can I rely on CDs and DVDs for storage when I copy them without errors?

I have old CD and DVDs. I am copying the files I have on these discs to my hard drive, but can I be sure that these files are not broken? I copy these files with no errors and don't want to keep the ...
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1answer
72 views

Excel Formula show with result as well as [closed]

I have a sheet with: A B C 7 5 =A1+B1 So, C1=12. Is it possible that D1 shows the numbers 5,7 used in the sum in C1?
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2answers
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What is the best way to make Calculate SHA1 as a context menu option in Mac OS X?

In order to calculate the SHA1 checksum of a downloaded file, I could type /usr/bin/openssl sha1 in Terminal and then drag there the file which I want check. To make it simpler, one could enable a ...
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2answers
447 views

Is it possible to recalculate the system configuration checksum on a Cisco RV180W

My Cisco RV180W has a corrupt configuration which is breaking the user interface in a few places. After a factory reset, it's fine - but if I restore my previous configuration it breaks again. The ...
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226 views

How do I check integrity of a file from DreamSpark?

I have a very unstable connection and it cut off multiple times while downloading Windows 8.1 using Microsoft's SDM, so I'm kind of concerned to how I can check to see if the file is still intact once ...
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3answers
2k views

Looking for OS X utility to verify/validate copied files/directories - checksum / SFV / MD5

Looking for the best way to easily validate the integrity of files/folder in OS X when copied from one location to another. I've downloaded SuperSFV but it appears to be very slow. Also new to the ...
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3answers
5k views

Is it possible to download corrupted torrent files, even with a download client builtin checksum verification?

I downloaded some mkv/mp4 files with my new router (I can download directly from it, using transmission), and all of them seem to be corrupted: lags, strange artifacts when using vlc, crashes with ...
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3answers
2k views

Is there anything like HashTab for Linux?

I've recently installed Linux, and I know that you can use "md5sum filename" in terminal, but on Windows there is an AMAZING software called HashTab that incorporates it into the shell. Its awesome, ...
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2answers
2k views

Calculate checksum of file from right-click menu? [duplicate]

Possible Duplicate: Looking for MD5 utility that integrates to Windows What would be the easiest way to have the checksum of a file shown in a message box using the right click menu on the ...
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3answers
4k views

How can I copy files to an external drive and verify their integrity in OS X?

I'm moving large amounts of data from one external drive to another larger one. The files are important and the smaller drives need to be cleared and reused (HD camera). Is there some utility for ...
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2answers
47 views

File integrity checking

I have a lot of PDFs and many of them may be corrupt. Rather than checking each one, how could I check them all at once and delete any that are corrupt? Using Linux. I also don't have a way to get ...
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3answers
61 views

Extract identical files from two directories

I am looking for a linux solution for the following problem: Given two directories with a large number of files. All file names are random and different in both directories. The contents of some of ...
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6k views

“CMOS check sum error” while booting

I am using an HCL desktop system (Core 2 Duo, 1 GB RAM, Windows XP SP2). While booting I got the following message. CMOS check sum error. Press f1 to continue When pressing F1 it is working ...
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1answer
2k views

Windows 8.1 Checksum

I've looked all over for the sha-1 or sha-256 checksum for the windows 8.1 iso that you get with the Microsoft’s “Upgrade Windows with only a product key” page but none of the check sums provided on ...
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1answer
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Microsoft Windows ISO checksums

Is there an official source for Windows ISO (XP+) checksums, online? Wanting to download some older Windows versions, for support purposes, but they don't appear to be available on Microsoft's ...
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0answers
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Video upload checksums not matching

We have a setup that takes a small quantity of small video uploads directly from people's mobile phones using apps, onto a small VPS. It rejects them if the MD5 checksum on the phone doesn't match the ...
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votes
3answers
652 views

How do I verify the authenticity of a linux system executable?

I'm aware of md5sum and gpg but I have no idea if there are recorded checksums for whatever current version of ubuntu is installed. Do these get recorded somewhere? Specifically I'm suspicious that ...
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1answer
1k views

How to get rid of UDP checksum error messages in virtual console?

Whenever I am streaming a video in the web browser, while connected to my school LAN via ethernet, and switch to the virtual console (ctrl-alt-f1) on Ubuntu, I get an error that looks like the ...
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votes
1answer
6k views

How is TCP/UDP checksum working?

I used raw socket to create some UDP packets and then send them to a UDP server I notice that when I put a wrong UDP checksum number the UDP server doesn't accept it, but if I put all 0 on the ...
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votes
1answer
2k views

Does Windows calculate CRCs to check every file operation?

When Windows encounters a file corruption on a file system, it may return the following error message: Data error (cyclic redundancy check). This suggests Windows checks every file operation ...
2
votes
1answer
121 views

File corruption detection strategy

due to current high price of hdds, I would like to switch from running RAID1 to JBOD + offsite backup (Backblaze). In theory it's a much better approach (if PC gets fried by lighting strike, I still ...
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votes
1answer
3k views

Is it possible to check a PDF for data corruption?

I have some PDF documents and I'd like to check them for possibile data corruption, even if I'm able to display them without problems. I don't really know if PDF documents store an embedded checksum ...
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269 views

how to backup only files paths, names, sizes and checksums?

I'm looking for an application which will allow me to select some folders, and then regularly backup only complete paths, names, sizes and checksums of the files within those folders and their ...
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0answers
142 views

Window Vista cannot create new folder, note, etc when right click and recent items forever empty after crashes

Basically my computer crashes and after I reboot I got a checksum error, so I reboot again and these problems appears: 1):Unable to create new folder, notes, zip file,etc. (when I right click in ...
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vote
1answer
247 views

Tool to maintain/keep track of filesystem content integrity?

I'm looking for a tool to maintain the integrity of a filesystem and it's contents using checksums. Effectively storing a list of checksums/filename pairs somewhere on the filesystem in a way that can ...
2
votes
0answers
93 views

MD5 for Git's git-credential-osxkeychain executable? [closed]

I'm setting up a GitHub account and have downloaded Git's credential-osxkeychain executable via the Password Caching section of GitHub's instructions. But... I am paranoid enough to look for some ...
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votes
2answers
1k views

Is verifying a MD5 sum after copying 100GB of data safe?

I'm copying 100GB from a Windows 7 workstation to 2 external drives (if you have only one backup, then you have none). All files have a MD5 checksum. I've verified all MD5 checksums on the external ...
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Cannot open an encrypted file on OS X

I cannot decrypt files on OS X (10.6.8 and 10.8.2) which I have encrypted on Ubuntu (10.04) using ccrypt. As a similar problem, I have a password file created with KeePassX. I just cannot open it on ...
5
votes
1answer
3k views

recursive file/directory verification on linux

What would be a command structure or simple bash script to run to compare all files in one directory with all files in another directory, verifying their data are identical, or not, down to the bit? ...