I have only recently looked up what it means to hash a file. I know, I know… I should be banned from ever being able to download or create anything, ever again!

Not to sound like a total noob, I knew it was a file verification system, I just didn’t realize how EASY it was! (By “easy”, I am referring the process of verifying the hash given, not the process of calculating.)

For those that are coming across this for the first time, a checksum is a value based on the contents of a file or files. I believe “hash” is the name given to the process of calculating the value. (fact checking is overrated!)

Let’s say you have a program that you distribute from your website. You run it through a hash, and come up with a value. We’ll call it “s8923ioa8d83lnksa”. (I believe the characters would have hexadecimal values and be longer, but we are just spit balling here.) You would post this on your site for audience to check the validity. Anyone who downloads the file and runs it through the same process would get the same result. If someone wanted to enter malicious code, or even an extra space, and redistribute your software, it would generate a completely different code.

There are MANY different algorithms available, but the most common ones I found are md5, SHA1 & SHA256. (PS, hashing is designed for data integrity, NOT security.)

To see how easy it is, there is an online hash generator available here. If you google something to the effect of “check hash of file”, you will get plenty of results of instruction and resources to narrow down to test on your own machine. (There are too many options to go into here!)

Did you say you wanted an example? Ok, here you go! Download this file… Use online method listed above, and you should receive one of the values listed below, depending on the method chosen.
MD5 – F8E0A590A4FB9DF58247086D4227977C
SHA1 – 15E03535436C775C15A820B7C339936180D8AD79
SHA256 – 4463FEFA7E8B2101B9B11E3B638FD0AFE19FFBF5132F232F2AF3B017C6C812E2

And there a quick post about something I knew virtually nothing about, and now know just a little more! 😉