Data Integrity – Check Those MD5’s

Data Integrity… It’s Important.

I’m sure many of you like to flash ROMs on your phone. That means you’ve all seen a developer give a MD5 Sum below the download link of their ROM. ROMs can be anywhere from 80-200+ MBs. They are large.


Alright, so… do you know what the heck this long string of number is used for AND how important they are? If so… you can quit reading. If not, this is for you and it could really save you some headaches down the road.


From Wikipedia: The MD5 (Message-Digest Algorithm) is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. MD5 is commonly used to check data integrity.


Great, thanks for the long definition Callip – Why should I care?


Well, next time you ODIN to JFD (or download a ROM) you will care a lot if you have issues. Having written many guides for the Vibrant on how to ODIN to JFD, how to root and how to flash ROMs, I get a lot of questions sent my way… and a lot of the time, it is simply a bad download. From ODIN hanging to issues with ROMs… often it’s simply a bad download.


If this was checked BEFORE flashing your phone you could save yourself a lot of time and a headache. The best part – it is incredibly easy to check an MD5 Sum.


My preferred method is using HashTab (Download Link). It is free, it is easy, and it’s available for Windows and Mac. Simply download and install it.


How do you use it? That’s the easy part.


When you download a ROM to your PC, all that is required is to right-click on the file. Then click on the tab “File Hashes” – it will scan and generate the MD5 (as well as other hashes not used).


Now, copy the MD5 that your thoughtful developer put under his download link and paste it into the “Hash Comparison” box. Click the “Compare” button…. It lets you know if your file is in good order. If all good, flash away sailor… if not, delete the file and download again because you do NOT want to flash that on your phone.


If this helped, share it (please)… happy flashing.


About s15274n

I will do what I can to help support the Android Community!

Posted on July 21, 2011, in Advocate, Flash and tagged , , . Bookmark the permalink. 1 Comment.

  1. I am yet to come across a bad download but I still check anyways. Guess I might be a bit paranoid but it only takes a couple seconds to check and if it goes wrong it will take a lot longer than that to fix.

    Lets hope the good streak continues… 🙂

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