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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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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1answer
53 views

Rename files by md5 checksum

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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5answers
397 views

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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2k 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
201 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
151 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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1answer
660 views

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
16 views

Why is sum command faster with smaller blocks?

On my machine using a normal hard drive, a sum -s on a 5 GB file takes 2 seconds, while sum -r takes 5.5 seconds. -r use BSD sum algorithm, use 1K blocks -s, --sysv use System V ...
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1answer
77 views

Checksums dont match is that bad?

I recently started looking at VisualStudio 2012. I tried downloading it from the official microsoft link but it fails with some errors.As of some suggestions I downloaded the DVD5 ISO image to install ...
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1answer
107 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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0answers
16 views

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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3answers
214 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
433 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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1answer
2k 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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1answer
316 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 ...
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1answer
85 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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1answer
2k 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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2answers
307 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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2answers
105 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
114 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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1answer
918 views

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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1answer
100 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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3answers
287 views

Merge two Foldes (Backups from my Files) on Windows 7 or Ubuntu 12.04

I have yearly backups of all my files on the harddrive. The problem is that the Backup from 2007 contains files which don't exist in 2008. And I need both Versions of the Files, when they are ...
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1answer
208 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 ...
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0answers
78 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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2answers
403 views

Undeletable Folders [duplicate]

Possible Duplicate: Windows Updates Folders (With Strange Names) in C drive I have 3 Folders on my D: - Drive they seem to be auto-generated by Windows their names are: ...
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2answers
889 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 ...
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1answer
660 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? ...
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2answers
945 views

How do downloads become corrupt? (SHA1 value varies)

I downloaded VS 2012 using IDM. While I did pause and resume several times, it downloaded successfully. BUT, the SHA1 and CRC values do not match with the given values in the website. This means that ...
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3answers
3k views

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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1answer
131 views

On Mac, after downloading a file, how to you do a checksum?

I want to do a checksum on a file I downloaded on my Mac. How can I do this?
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5answers
1k views

File checksum calculator for Windows [closed]

I'm looking for a light, fast hash/checksum calculator (eg. MD5, SHA1, etc.). I've been using HashCalc and it works fine enough, but I was wondering if there was something better. When downloading ...
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1answer
356 views

Is there a utility to verify the checksums of every Windows file?

I would like to know if there is a utility to verify the checksums of every Windows file on my Windows 7 Ultimate system. It seems on the surface such an obvious utility but I don't ever remember ...
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2answers
2k 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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2answers
302 views

How to do checksum on web hosting site?

I am having problems uploading a large file to a web site. When the file is subsequently downloaded it is corrupt. How can I do a checksum of the file while it is on the web site so I don't have ...
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2answers
535 views

TCP Checksum, why?

Why does TCP need a checksum, when lower layers do integrity checks anyways (like Ethernet CRC)?
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2answers
3k 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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votes
7answers
1k views

SFV Software Recommendations?

I'm looking for software recommendations for generating/validating SFV files (CRC32). I currently use "Easy SFV Creator", which is a great software but sadly it's no longer being maintained, and the ...
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6answers
205 views

Checksum for Protecting Read-Only Documents

My father owns a small business and has to hand over several year's worth of financial documents to his insurance's auditor. He's asked me to go through and make sure everything is "read-only" so the ...
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1answer
131 views

sourceforge checksums: Where are they? [closed]

I've been particular about checksumming all downloaded software. Today, trying to download from Sourceforge, I could not find any checksums for the projects. Am I just missing them or are they not ...
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1answer
178 views

Where can I find checksums for the GlassFish Server 3.1.1 Open Source Edition Full Platform zip file?

I've downloaded the Glassfish zip file from http://glassfish.java.net/downloads/3.1.1-final.html and I'd like to verify the integrity of the file, but I can't find any checksums. Where can they be ...
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votes
3answers
1k 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 ...
2
votes
3answers
218 views

How do I check the checksum of a download and why should I?

My memory isn't great but I think five or six years ago, when I downloaded some package, there was never a checksum line under the download icon on the webpage. And no instructions to "check the ...
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2k views

Checksumming an entire CD/DVD

I'm publishing a set of documentation to be delivered on CD. My Company's European production manager is concerned that he has no way to verify that the data on the discs he produces is correct. He ...
2
votes
1answer
72 views

Backup solution: hash/checksumming and/or error correction

I'm trying to keep my data well protected with backups, using multiple hard drives (basically swapping the backup disk out every week). For checking validity, I was originally planning on md5summing ...
4
votes
3answers
1k 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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3answers
800 views

Solution for noisy network that corrupts downloaded files

The network on the company where my wife works sucks BIG TIME. Almost every single file bigger then a few hundred kB is corrupted during download and even web pages are sometimes garbled. We checked ...
2
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1answer
592 views

Is it possible to check a FLV for data corruption?

I have some FLV videos and I'd like to check them for possibile data corruption, even if I'm able to play them without problems. I don't really know if FLV videos store an embedded checksum string for ...
2
votes
2answers
592 views

Verification of files on backup media - after the backup

I have a system in place where I back up my work files daily to a portable hard drive. I actually have two portable hard drives - one is stored off-site and I swap them regularly. I also keep my ...