Software Review: WinMD5Sum

Program: WinMD5Sum
Publisher: Nullriver Software, www.nullriver.com
Category: Utility to verify integrity of download
License: Short, custom user-friendly license
Price: Freeware

First, I need to explain what MD5 is. MD5 is a hashing algorithm (a number-crunching method) that is designed to read every byte of a file and generate a long, unique code based on its contents. md5Sum is a program in the Linux world that is used to generate verification codes for software files.

The most important features of an MD5 sum are that: (1) it is easy to use and (2) if a single character/byte changes in the file, the MD5 sum is dramatically different.

md5sum is often used when Linux programs are made available for downloading. Since most of the programs are open-source and free, and anyone can distribute them, the publisher often uses md5Sum to create the unique identifying sequence of characters for the file. That way, you can download from anywhere, but still use md5sum on your own computer to calculate the MD5 sum verification code, and compare it to the MD5 sum published by the originating site.

Tech Tip
By the way, the MD5 sum for the downloadable proggram Install-winMd5Sum.exe is 7d2b88b560095b9a59576fc75cdb1ef5.

So, what is WinMD5Sum? You guessed it — a Windows program to calculate an MD5 sum.

Sometimes, Windows programs are distributed with MD5Sums, or Linux programs may be downloaded to a Windows computer. By using WinMD5Sum, we can calculate the MD5 sum to make sure that we downloaded an unmodified file and also confirm that there was not a bad download.

What do I use it for? I often will download a Linux distribution in the ISO image format, so I can burn a CD of it. WinMD5Sum allows me to make sure that the file is the same as the original and that the download process did not corrupt the file (which sometimes happens).

What else does WinMD5Sum do? Nothing.