There are many developers here at XDA who are blessed with the gift of knowledge. However, not all of us are technically saavy and hence can easily get in trouble for lack of knowing things. This is particularly true for developers who are just beginning. How do you know that the files that you are downloading to help with your app are real? And even if they are real, how do you know that they haven’t been tampered? It is very easy to modify files to do all sorts of things (both good and bad), which is the more reason one has to be ready.
XDA member SpeakEZ just put out a guide which describes what MD5 Check Sums are, how they can be used, and more importantly, how to check them. This guide should help beginners and seniors alike in understanding the “mystery” behind check sums.
What is an MD5sum?
An MD5sum is a commonly used hash value that is created to verify the integrity of files. Here at XDA-developers, MD5sum values are provided by developers to allow users to verify that a file download is not corrupt or been altered.
This is a security feature that XDA users are provided with to verify the integrity of downloaded files for personal use.
DISCLAIMER!: PROCEED WITH CAUTION! I AM NOT RESPONSIBLE FOR ANY DAMAGE CAUSED TO DEVICES! YOU SHOULD NEVER USE/OPEN A DOWNLOADED FILE IF THE MD5SUMS DO NOT MATCH!!! USE/OPENING OF A CORRUPT FILE CAN LEAD TO DEVICE MALFUNCTIONS OR FAILURE!!!
You can read the full guide in the original thread.___________________