What is MD5 Sum?
MD5 is a widely known term in the tech world but if you are an active Android users, you must have confronted the terms like “md5sum”, “md5 hash” or “md5 checksum” quite frequently. Most official and custom ROMs, mods and recovery flushable ZIPs come pre-encrypted with a unique code for security reasons. It’s a kind of password that is used to ensure the integrity of files inside a ZIP or a software package.
An MD5 checksum is a mathematical algorithm is usually a set of 32-character hexadecimal letters and numbers that are computed on a file with a tool. These numbers are generated using special tools that employ “cryptographic hash function producing a 128-bit (16-byte) hash value”. It is used not only to encrypt a ZIP archive or an EXE installer but all kinds of files. You can assign an MD5 sum even to a text or document file. The perfect match of MD5 checksum value ensures that the digital integrity and security of a file has not been broken by someone else and also that it is the accurate copy of the original file.
Thus, there are the two main reasons if the MD5 hash value of a file you downloaded does not match against the original sum:
- The file might be modified by someone else in an unauthorized way.
- The file was not downloaded properly and some of its elements might have been corrupted.
The MD5 checksum or hash value of a file might look like these:
25912deacc5d55528e223ec7b99705cc
220c41f3b03f42190899db8cb081b5c6
a578d837343fe2542ecf405a630d46a0
8223ec1c2aa71503b431a0daabb23154
Why to Verify MD5?
Installing an official firmware, a custom ROM or even a Kernel file with corrupt MD5 value can lead to a bricked phone or tablet. It is, therefore, very important that whenever you download such files with a purpose to install them on your device, make sure to compare/match the computed MD5 checksum against the one provided on the download page to verify their integrity. I have seen various cases where people report that their device went to bricked state after installing a certain file. In many cases, you might get an installation failed error if the MD5 hash value is not correct.
It is a customary practice among Android developers to mention the MD5 sum of their ROMs, mods, and kernels when they share them. Having downloaded such files, you can run an MD5 checker program on your computer to match the MD5 value. It the sum matches perfectly; you can proceed to install the file. In case there is a mismatch between the values, you should avoid installing such files.
To make sure that it is just a case of bad download, try downloading the file again, preferably from a different mirror or browser. If the match fails again, contact the developer and report it. He/she might check if the MD5 they provided was correct or give you an alternate link to get the file.
Verify MD5 Checksum on Windows
If you are a Windows user. you can find a variety of MD5 checksum programs available on the internet that can be used for the purpose. Personally, I use a very nice and easy to use a tool called WinMD5Free. Here is how you can use it to verify:
- Download the latest version of WinMD5Free from the official site: Click Here [mirror]
- Extract the downloaded zip and launch the WinMD5.exe file.
- Click on the Browse… button, navigate to the file that you want to check and select it.
- Just as you select the file, the tool will show you its MD5 checksum.
- Now copy and paste the original MD5 value provided by the developer or the download page in the box below.
- Then click on Verify button.
- The tool will then give you the match results and shown above.
How to Check/ Verify MD5 CheckSum of a File on Windows, Mac and Linux
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