Dev team just updated the recently released version redsn0w 0.9.6rc9 to bring an untethered jailbreak for Apple's latest firmware ios4.3.1. The redsn0w 0.9.6rc9 works on iphone 4, 3gs, iPod touch 2G/3G/4G that actually support 4.3.1 except for the ipad2.
NOTE: If your iPhone 4 rely on an unlock, do not update to iOS 4.2.1 yet as doing so will upgrade your baseband, making it impossible for now to unlock.
Step 1: Download iOS 4.3.1 (iPhone 4 (GSM), iPhone 3GS, iPad, iPod touch 3rd gen, iPod touch 4th gen)and Redsn0w 0.9.6rc9(Mac,Windows) for your device
Step 2: Connect your iphone via USB to your computer and Restore iOS 4.3.1 firmware using the IPSW file via iTunes 10.2.1
Step 3: Start Redsn0w 0.9.6rc9, click "Browse" and choice the official iOS 4.3.1 firmware, and then click "Next".
Step 5: Make sure your device is both OFF and PLUGGED IN to the computer, and click "Next". Use the following instructions to enter DFU modern. A. Turn off your device. B. Turn on your device and then while holding the "Power" button for three seconds, after this you will now have to hold the ""Home" button too. After ten seconds release "Power" button but continue holding "Home" button for thirty seconds.
Once done, your device will restart automatically and jailbreak successes!
