iPhone 4, after unlock, then upgrade, will still be unlocked?!

lily69

macrumors regular
Original poster
Apr 4, 2010
134
0
I am reading this link:
http://www.gadgetsdna.com/iphone-4-jailbreak-and-unlock-in-single-tool/4987/

It says: a successful bruteforce of your unique unlock code would give you your permanent unlock, no ultrasn0w needed

Since I am only interested in unlock not jailbreak, does this mean the new unlock tool will make my iPhone 4 unlocked just like factory unlock, and I can upgrade to official software, become none-jailbroken but still remain unlocked?
 

benflick

macrumors 68020
Jul 11, 2008
2,148
0
Cincinnati, Ohio
No, this means that Ultrasn0w will work like it always has--a soft unlock. The Dev Team can only produce a soft unlock. A bruteforce unlock is what Apple uses in countries like Austrailia and France which require phones to be unlocked. A bruteforce unlocked iPhone will remain unlocked forever, an Ultrasn0w unlock will not.
 

jdong

macrumors member
Nov 24, 2008
33
0
I am reading this link:
http://www.gadgetsdna.com/iphone-4-jailbreak-and-unlock-in-single-tool/4987/

It says: a successful bruteforce of your unique unlock code would give you your permanent unlock, no ultrasn0w needed

Since I am only interested in unlock not jailbreak, does this mean the new unlock tool will make my iPhone 4 unlocked just like factory unlock, and I can upgrade to official software, become none-jailbroken but still remain unlocked?

No. Ultrasn0w on the iPhone4 simply allows you to dump out the "secrom" of the baseband which contains the hash of the NCK unlock code you need to enter to permanently unlock the unit.

However, to actually brute force the code based on this information is STILL a pretty insane effort (maybe a few months of computational power with a respectable CPU+GPU), so you can feel free to spend $500 on electricity or whatnot to give it a shot, but it's probably not the best use of your efforts.

The key point is that without access to the secrom, brute-forcing would be impossible. Ultrasn0w just makes it possible -- whether or not it's practical is a different story.
 

dhlizard

macrumors G4
Mar 16, 2009
10,214
118
The Jailbreak Community
No. Ultrasn0w on the iPhone4 simply allows you to dump out the "secrom" of the baseband which contains the hash of the NCK unlock code you need to enter to permanently unlock the unit.

However, to actually brute force the code based on this information is STILL a pretty insane effort (maybe a few months of computational power with a respectable CPU+GPU), so you can feel free to spend $500 on electricity or whatnot to give it a shot, but it's probably not the best use of your efforts.

The key point is that without access to the secrom, brute-forcing would be impossible. Ultrasn0w just makes it possible -- whether or not it's practical is a different story.
Glad you cleared this up since early posts were way wrong....
 

mkrishnan

Moderator emeritus
Jan 9, 2004
29,777
12
Grand Rapids, MI, USA
A bruteforce unlock is what Apple uses in countries like Austrailia and France which require phones to be unlocked.
This isn't correct, is it? I find it hard to imagine that Apple is implementing a brute force technique on its own product to unlock it... that seems absurd.

OTOH, I do miss the relative permanence of the unlock on the original iPhone. I wish I could even just permanently unlock my 3GS just in case.
 

thelatinist

macrumors 603
Aug 15, 2009
5,934
49
Connecticut, USA
This isn't correct, is it? I find it hard to imagine that Apple is implementing a brute force technique on its own product to unlock it... that seems absurd.
No, it's not correct. But the result of the kind of brute force technique they're talking about would be a "factory" unlock.
 

thelatinist

macrumors 603
Aug 15, 2009
5,934
49
Connecticut, USA
Do you know any details of what a factory unlock actually is? In other words, do they use software or is some type of hardware change that allows this?
The factory unlock is done during activation. AT&T sends an encrypted unlock token which is unique to your device. I understand that with this seczone dump it is theoretically possible to find that token by brute force. You could then spoof the activation server and permanently unlock your phone.
 

mkrishnan

Moderator emeritus
Jan 9, 2004
29,777
12
Grand Rapids, MI, USA
The factory unlock is done during activation. AT&T sends an encrypted unlock token which is unique to your device. I understand that with this seczone dump it is theoretically possible to find that token by brute force. You could then spoof the activation server and permanently unlock your phone.
Right, what you're saying makes sense, thanks.
 

moussekateer

macrumors 6502a
May 12, 2009
733
0
I recall someone a year or so again collecting NCK codes and sec zone dumps from people officially unlocking the phone. He was trying to find the algorithm to generate the NCK codes, but needless to say he didn't get anywhere. As already mentioned it's a huge computational effort. If someone were to find the algorithm though, it would mean every iPhone in the world could be easily unlocked. Only a dream though
 

The General

macrumors 601
Jul 7, 2006
4,826
1
If you brute force your unlock code, which apparently is a possibility on iPhone 4, then your phone will be unlocked forever no matter what.
 

thelatinist

macrumors 603
Aug 15, 2009
5,934
49
Connecticut, USA
I recall someone a year or so again collecting NCK codes and sec zone dumps from people officially unlocking the phone. He was trying to find the algorithm to generate the NCK codes, but needless to say he didn't get anywhere. As already mentioned it's a huge computational effort. If someone were to find the algorithm though, it would mean every iPhone in the world could be easily unlocked. Only a dream though
MuscleNerd has said that it doesn't appear to be algorithmic. Apple must keep a database of every phone's unlock code on its activation server.
 

moussekateer

macrumors 6502a
May 12, 2009
733
0
Brute force is still possible, but might take billions of years. ;)
But there goes the dream of a tool everyone could use to instantly unlock their phone. Would be funny if someone was brute forcing their code and it was the first attempt, 0000000000000000000001 haha
 

cal6n

macrumors 68000
Jul 25, 2004
1,935
24
Gloucester, UK
The factory unlock is done during activation. AT&T sends an encrypted unlock token which is unique to your device. I understand that with this seczone dump it is theoretically possible to find that token by brute force. You could then spoof the activation server and permanently unlock your phone.
Close, but it has very little to do with AT&T or any other carrier. They just tell Apple when one of their customers' iPhones needs unlocking.

Apple keeps a database of these unlocked iPhone IDs that is checked by iTunes as required. If your phone's on the list, iTunes makes sure it's unlocked.

When Apple sells an unlocked iPhone, in the UK for example, its ID gets added to the list. However, once an iPhone has been assigned to a carrier, such as AT&T, only that organisation is authorised to add that phone to the database.