With the release of the iPhone, a lot of people have been trying to find a way to crack the AT&T lock on the product. The iPhone Dev Wiki hackers have been able to partially unlock the iPhone using a new application called iASign.

This program doesn't fully unlock the iPhone for use with all service providers, but the hack will allow you to use any existing Cingular/AT&T Pre-paid/MVNA SIM in the phone to place calls.

Currently, the hackers working on this project have been gearing up for a final assault on the unit with the ultimate goal of completely cracking the iPhone and giving it full functionality regardless of the network.

Certain issues have been blocking their attempts. The main problem of cracking the iPhone lies in the baseband or the radio chipset for the iPhone. The iPhone only has one lock which is a network personalization lock which is located in the baseband firmware itself.

The AT command to do the unlock is 'AT+CLCK="PN",0,"xxxxxxxx"'. The big problem is finding out what those x's are. Brute force is out of the question since there is a limit of 3-10 unlock attempts per phone, after which the firmware will "hard-lock" itself to AT&T.

Patching the firmware at /usr/local/standalone/firmware/ICE03.12.06_G.fls is difficult as well, considering that it's signed. The signature is checked in the baseband bootloader while the updater program, bbupdater, only checks a checksum, which can be changed. The update will take, but then the phone will refuse to boot because the signatures don't match.

The hackers have already worked two solid days in their attempt to disassemble the radio fw and have found a few backdoors. So far, none of these lead to an unlock, s the hunt is still on for a way to crack the code.