Bitshift

The iPhoneSIMFree folks -- the people who were selling a software-only SIM unlock to resellers to mark up as they saw fit (often around $100) -- released their software yesterday. Today, people began posting the app to the net. This afternoon, people began reverse engineering it, because no matter what magic IPSF did on the back end, it still had to modify the baseband memory via software, something that George Hotz couldn't manage without a hardware hack.

In the past hour, it was discovered that there's a bug in the way the iPhone bootloader's checking the validity of the baseband firmware file, and thus making a decision whether or not to execute it. This is what IPSF takes advantage of, and this is what the dev team have independently verified can be used to trick the phone into loading a modified baseband firmware.

There will be a free, zero-cost, open-source full software SIM unlock for the iPhone released to the world in the next few hours.


Keep in mind, however, that this is a bug that is easily patched by Apple in an upcoming iPhone firmware release. This means that the free solution may stop working at any time in the future, and also that the commercial versions will also stop working. Which in turn means that all those people that spent $50-$100 to unlock their phone will be forced to spend another $50-$100 to unlock it again when the software stops working.