iPhone 3GS MobileMe remote wipe is SUPER fast - almost TOO fast!

[ProPedderKustom]

I did a total wipe of my iPhone 3G that was running the 3.0 software on Friday - it took about 2 full hours. Today, after exchanging my iPhone 3GS due to battery issues [https://forums.macrumors.com/threads/731925/] I decided to remote wipe via MobileMe. It literally took 2 minutes and then said it needed to be plugged into iTunes.

This seems WAY too fast to be doing a FULL wipe. What gives?

The reason I did it this way is because wiping from the phone resulted in my 3G staying in my MobileMe Find My iPhone section, despite being wiped and sold to someone else. I didn't want this happening with my 3GS as well.

 

[plinx0r]

If I understand correctly everything is encrypted by default. When you initiate the wipe process the only thing that is deleted is the key used for decryption. So even though your data persists, it will remain in an encrypted state and useless to anyone even if they get their hands on it.

 

[PhixionFilms]

I thought when you usually restore your phone, itunes does - step 1. Erases your current settings (takes about 1 minute) 2. Then puts the newer OS on (takes about 15 mins).
I think when mobile me deletes your settings, it just does step one. Doesnt reinstall the os.
Im just guessing, i havnt done this myself.

 

[b.c.]

If I understand correctly everything is encrypted by default. When you initiate the wipe process the only thing that is deleted is the key used for decryption. So even though your data persists, it will remain in an encrypted state and useless to anyone even if they get their hands on it.

this is correct, the wipe simply deletes the encryption keys rendering the memory contents useless. the 3GS has hardware support for encryption too.

meanwhile the old 3G does not do this, wipe is simply zeroing out the entire memory, that's why it takes so long. also there's no hardware encryption on the 3G either.