May 4,2014 Posted by Allen Lee to Guides
To decrypt and open a msgstore.db.crypt6/msgstore.db.crypt7/msgstore.db.crypt8 WhatsApp backup file, your Key file is required. The following article will show you how to obtain your key file from your Android Phone:
For Android 4.0 or earlier
Step 1: Root the Android device from which your crypt file was created. You can check this tutorial on how to root android phone in one click.
Step 2: Copy Key file from Android to computer Method A: Use our Backuptrans WA Sync app to copy the key file onto Phone Storage. Just run Backuptrans WA Sync on your phone and click “Copy Data” button. Then you wil find your key on Phone Storage sdcard/WhatsApp/ or /storage/emulated/0/WhatsApp/. Please copy the key file from Phone Storage onto your computer.

Method B: Use our KeyExtractTool to copy the file from your root Android device directly onto computer. To do this: 1): Download the KeyExtractTool from the following link onto your computer. Windows version KeyExtractTool Mac version KeyExtractTool 2): Unzip the download file on your computer then you will see a file called run. 3): Connect your root android device to computer via USB and then click the file run to obtain Key file. 4): Done. You will see the key file next to the file run.
Step 3: Run Backuptrans WhatsApp Transfer software to open Crypt6/Crypt7/Crypt8 file Now you can run Backuptrans software and then select the obtained Key file to decrypt the msgstore.db.crypt6/msgstore.db.crypt7 file.

For Android 4.0 or newer
Step 1: Run Backuptrans WhatsApp Transfer software on computer.