How to check downloaded file integrity

I do it for work and for play. Linux rocks! Where would you like to share this to? Twitter Reddit Hacker News Facebook. Share link Tutorial share link. Sign Up. DigitalOcean home. Community Control Panel. Hacktoberfest Contribute to Open Source. By Michael Holley Published on June 7, How File Verification Works File verification, also known as hashing , is the process of checking that a file you have on your machine is identical to the source file..

Performing File Verification on Linux Most Linux distributions have command line tools for each hashing algorithm.

Execute the md5sum command and pass it the path to the file you want to hash: md5sum mini. About the authors. Michael Holley. Brian Hogan. In the context menu, select Open Command Window Here. Here, we can use FCIV to create a checksum for our file. In real-world use, it would look something like this: fciv steam. Next, you would open that. Next, you can take that value and make sure it matches up with the checksum value you got from a friend or from the company who owned the file.

In this case, you can try another download source and try the checksum process again. You could be putting your computer as well as all of your data at serious risk. If your checksum value that you got from FCIV does not match up to the checksum value provided to you, that means that the contents of the file has changed from someone other than the developer.

Another Microsoft program built into Windows is CertUtil. Again, it operates in a similar fashion to FCIV, but the commands are slightly different. Here is an example. The long string of characters above is the checksum. If you were running a checksum against a file, the name would be listed instead of a dash.

Here we generated a checksum of a text file containing all lines of the short story Harrison Bergeron by Kurt Vonnegut. If we edit the file and change one character, the checksum will change. Even though we only made a very small change in the file, the checksum is dramatically different. This allows you to easily notice that the file has changed. In depth analysis of hashing algorithms is beyond the scope of this tutorial.

Some operating systems such as Linux, MacOS, and Windows allow verification of downloaded files through their hashes. In fact, every file has a unique data. The analysts apply a Cryptographic Hash Function to check the hash value of a program. This function verifies whether the file is in the current state or it has been modified by malicious actors. To be able to check the integrity of a given file, you only need a utility tool or a third party.

The commonly used third-party utility is:. This is one of the most efficient and most effective third-party utility program used to check the hash value of a file See Figure 2 below. It is an easy-to-use application whose premise is straightforward. After that, you need to select the file that you want its hash values generated and open it.