[lobeartery]

Hello, I got a new iphone 7 and plan to sell my old iphone 5, but there are many sensitive data stored on my iphone 5, i'm afraid that next owner could recover my private data, so, what should I do to make the deleted data unrecoverable? can I use "Erase all content and settings"?

[Just_Me_D]

If it were me, I'd logout of everything I'm logged into via the device, especially the Find My iPhone option. After that, I'd use the Erase All Contents and Settings option. After that, I'd put the device in DFU mode and have iTunes install a fresh full copy of iOS on the device, and when the process is finished and I'm at the Welcome screen, I'd turn off the device and proceed with selling it, but that Just Me, D....

[Ledsteplin]

Especially turn Find My iPhone off. It's in settlngs > iCloud.

[fury]

All user data is stored encrypted on the device, and the key it uses to decrypt the data is blown away when you hit the erase all content and settings button. For all intents and purposes, that will make the previous contents completely unrecoverable by any publicly known means. The raw encrypted bits look like random noise. It's way faster and more effective than a flat 1s/0s wipe, especially given NAND flash's wear leveling.

Here's a good deep dive into iOS security if you're interested in putting on your nerd hat and swimming in cryptographic acronyms: https://www.apple.com/business/docs/...Guide.pdf#mn_p

[Bushkesh]

Back when I had Android and decrypted, I would wipe and fill the entire user storage with useless contents. Then I would wipe again and once again fill it up with junk. That's how I would know for certain that if someone tried to recover anything all they would get was porn lol. But considering iPhones come default with encrypted partition and no way to disable it's safe to assume that a simple Erase will do.

[uliapalm]

For old phone like iPhone 5, filling random data to the device is more secure than factory reset. However, for newer iOS device, a simple factory reset is enough to protect the data.

Official tutorial: https://support.apple.com/en-us/HT201274
How to fill random data to iphone: http://www.safewiper.com/tutorials/h...pod-clean.html