How to survive app from hard reset android phone?

Question

i've seen apps like Cerberus which can survive hard reset of phone. I want to add similar functionality in my app that has security features such as anti theft. So my question is: How to create a app that will survive hard reset to preserve some data that might be even used for further purposes, How can i prevent my app from hard reset of device?

I went through the .zip file from one of the app which is used to flash the app to the ROM but it didn't clear my doubts , can anyone clear the idea about how it can be done

Thanks in advance!

Answer 1

You can only do this if you have root permissions by moving the APK to /system/app. SuperSu, etc. offer this as an in-app feature. If you really want reliable 'security features' though, the app(s) should be part of the firmware, anything else is snake oil.

Answer 2

Why not store some data in a file on the SD card? You can simply retrieve this later and phone reset should not affect this. /sdcard is not wiped in a factory reset AFAIK.

See:

http://www.androidcentral.com/android-z-f-factory-reset

https://android.stackexchange.com/questions/33082/does-a-factory-reset-on-a-galaxy-nexus-wipe-the-virtual-sd-card-directory