How can I quickly remove all of my data from my device and then get it back again?

Question

Soon, I'll have to give my phone (a non-rooted LG Nexus 4) to another person for some time. As the phone contains very sensitive information, I do not want this person to be able to access any of it. Unfortunately, I don't have data encryption turned on, so I can't just turn the device off and be sure that the other person won't be able to decrypt it.

Basically, I want to wipe my phone right now and then restore it to exactly the state it was before the wipe.

Therefore, I was thinking of backing up my device completely, wiping it and then restoring the backup. How can I do this? Will adb backup -all -shared -apk be sufficient? I guess not, since I'm afraid there are some settings that adb won't detect. Is there a lower-level way, like making an image of all the phone's memory with fastboot/recovery or something?

Answer 1

You would need to root your phone and install a custom recovery in order to make a nandroid backup of your entire system. There are YouTube videos on how to do this. Please remember that there are risks in rooting and in flashing recoveries.

Answer 2

If you don't want to root (as given in the other answers by @johnF and @Izzy) you can try an application called Helium which can backup your apps and app data.

A factory reset will remove all the data on your device... just make sure you check the backup to see that everything was indeed backed up before you do it.

Answer 3

As JohnF already states in his answer, a nandroid backup would be the first step. Basically, this creates an image of all partitions on your device (read more in its tag-wiki). But this doesn't cover the SDCard(s), which you would need to copy -- at least the internal, the external you could simply remove.

Now you've got your data backed up. But you still need to wipe your device. A factory-reset won't be enough for this, as it a) still leaves traces which can be carved, and b) might not even touch the SDCard. So for that, you might want to take a look at apps like Nuke My Phone, which safely wipe all data (i.e. not only delete the files, but overwrite everything with "garbage data"), so there's nothing left to recover.

Oh well, you can recover: Simply restore the Nandroid backup you initially created, copy back the data to your internal SDCard, and insert the external SDCard. Et voila, you're done :)