As we reported earlier that Dev team and Geohot will release jailbreak tool for iPhone 3G S after the release of OS 3.0.1 Now Dev team also confirms it in their latest blog post. Dev team talks about ECID, iBSS and iBoot. If these jargons are over from your head then read this post twice or thrice. Apple added a new piece of security called ECID, The nature of the 3GS hardware allows Apple to stop IPSWs from being usable unless you’ve already gotten the signed chunks they send to you based on your ECID (a unique chip ID). Actually Apple applies ECID so the iPhone will refuse to accept the ipsw file while downgrading because of a bad signature. It will treat it as a custom ipsw without having the apple server sign the ipsw specifically for your phone id before flashing.
Note : if you want to guarantee that you’ll be able to jailbreak then make sure you get the ecid+ibss sig dump asap. If you haven’t get ECID+iBSS signature dump then do hurry and follow our guide on Get Your 3G S iBSS Certificate for Upcoming Jailbreak.Follow these instructions to generate a unique certificate for your phones iBSS. And don’t delay, Apple may change their minds. To clarify, this is instead of a usb dump. Do this, and you are good! Also don’t update to 3.0.1 until Geohot or Dev team confirmation. We are expecting OS 3.0.1 within 2 weeks.
iBoot : This is Apple’s bootloader for the S5L8900 (application processor for iPhone 2G), S5L8720(application processor for iPhone 3G), and S5L8920(application processor for iPhone 3G S). It runs what is known as Recovery Mode. It has an interactive interface which can be used over USB or serial. iBoot makes sure that you are flashing a firmware version greater than or equal to a current one. If you are not, iBoot will not allow the restore to proceed. You can bypass iBoot by putting your iPhone in DFU mode. That’s why we used DFU mode for downgrading firmware.
ECID : This is a unique chip ID and will be different for every iPhone. When iTunes starts the restore process, they contact Apple servers to generate signatures just for your device. It’s important you get these signatures for your phone before a new version of the software comes out.