Does "Erase All Contents and Settings" really erase?

[iPhoneUserInNYC]

Or mark the flash memory pages as clean making them available for future use, and leaving the data as is? I'm preparing my iPhone 4S for sale having upgraded to iPhone 5 and want to make sure the data is actually erased. If it is not, are there any apps that bit-erase the data?

I used to SSH into my jali-broken iPhone 3 running iOS 3 and could see all the files. I have a nagging feeling that the new owner of the iPhone 4S could do the same by jail-breaking it, if the data still exist.

 

[AppleFan91]

As far as I know, yes, it deletes everything except the system files and OS. Meaning that all user data and settings are gone

 

[Mbman81]

As far as I know the latest couple of iPhones just have the encryption key dropped to prevent accessing the user data upon wipe. That's why it is so quick.

 

[NewYorkRanger]

Yes. Without the encryption key, data is lost forever.

Devices that support hardware encryption: Erases user settings and information by removing the encryption key that protects the data. This process takes just a few minutes.

http://support.apple.com/kb/ht2110

As far as I know the latest couple of iPhones just have the encryption key dropped to prevent accessing the user data upon wipe. That's why it is so quick.

Correct, All but original and 3G use hardware encryption.

 

[eastercat]

If you're really paranoid, erase in itunes, fill it up with music (or some other file you don't care about) then erase again. Overwriting the previously erased space is one of the most secure ways to erase.

Or mark the flash memory pages as clean making them available for future use, and leaving the data as is? I'm preparing my iPhone 4S for sale having upgraded to iPhone 5 and want to make sure the data is actually erased. If it is not, are there any apps that bit-erase the data?

 

[scootaru]

If you're really paranoid, erase in itunes, fill it up with music (or some other file you don't care about) then erase again. Overwriting the previously erased space is one of the most secure ways to erase.

HEADLINE: New York man fined $10 billion by RIAA. Man claims he just wanted to erase data from his iPhone.