Selling iphone: Secure erase data?

Discussion in 'Buying Tips and Advice' started by lumine01, Dec 21, 2014.

  1. lumine01 macrumors newbie


    Feb 23, 2008
    Is data recovery something that can be done on an iPhone, after it has been "wiped" and reset to factory defaults?

    Is there a way to "secure erase" any of the old files, other than overwriting the old data with newer files?

    Thanks for any advice/help!
  2. cruisin macrumors 6502a


    Apr 1, 2014
    I would first erase all settings since this is what will wipe everything. A restore should delete the encryption key but won't do anything for an older phone. This apple link explains it best. Older devices overwrite everything and newer devices delete the encryption key. Either way, you should be fine. Since this is part of the OS, it should work much better than any app you can get.

    If you are paranoid, you can erase then restore as a new phone and then erase again.

    A bigger worry is the weird way text messages are handled if you switch to a non-Apple phone and don't sign out of iMessage. You might not get your texts. See: Deregister iMessage.
  3. lumine01 thread starter macrumors newbie


    Feb 23, 2008
    That helps a lot, thanks for taking the time to explain it!
  4. rigormortis, Dec 22, 2014
    Last edited: Dec 22, 2014

    rigormortis macrumors 68000


    Jun 11, 2009
    the iPhone uses 256 bit encryption. every iPhone since the a4 system on a chip has had this feature.

    the iPhone is secure as long as you don't write the key down.

    when people say "30 characters should be enough !" on your wifi network, that is what your iPhone is dong automatically.

    dvd uses 40 bit keys and blu ray uses 128 bit keys. they would of had a hard time ripping star wars and terminator , if the keys weren't discovered, and given away

    don't write it down means don't jail break your device. if you jailbreak your device , it might backup your key somewhere.

    if you had a computer and it made 1 trillion guesses per second to try and get back the data you wiped, it would take :

    3.53 hundred million centuries

    here is a good reddit post

    a lot of crypto people say that AES-256 is so secure, that even the quantum computers in the future can't brute force your iPhone. (meaning the iPhone can't be recovered in the average human beings lifetime or the lifetime of the known universe)

    they can go after itunes backups and iCloud. but the iPhone, i doubt it
  5. lumine01 thread starter macrumors newbie


    Feb 23, 2008
  6. Andy2k macrumors member

    Jul 18, 2015
    If you're really paranoid. You can do a full restore and download iOS from itunes. That will reload the entire operating system which should completely write over your data. Press and hold both the power button and home button down until it boots into "recovery mode" Then plug it into your computer and launch iTunes. iTunes will detect it in recovery mode and ask if you'd like to download the newest iOS and restore your phone. Essentially doing a full factory reset on the phone.


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