Restore Encrypting File System

Encrypting File System, or EFS, is a partition where a device’s radio information or data is stored. You need to back up this partition before making changes to Samsung Galaxy devices because if you don’t your device’s radio could turn off and you will have no connectivity at all.

Flashing an invalid or inappropriate firmware can damage your current EFS partition and this result in a change in your IMEI to null. By backing up your EFS data, you can avoid this problem.

A great tool to use to back up your EFS data is the Samsung Tool App. This app can back up and restore EFS data on all Samsung Galaxy Devices. In this guide, we’re going to teach you how to use it.

Prepare your device:

Your device needs to be rooted. If it isn’t yet, root it.
You need to have Busybox installed.

Backup & Restore EFS using Samsung Tool:

Download Samsung Tool APK here either directly on your phone or on your PC. If you download it on a PC, copy the file onto your phone.
Locate the APK file and install it. If you are prompted, select Package Installer. If required, allow unknown sources.
When it’s installed, you should be able to access the app in the app drawer.
Samsung Tool will present you with several options, select if you want to Backup, Restore EFS or else Reboot your device.