ok so people are idiots when it comes to the decrypting iphone OS, I asked someone about this for their protection I will not release names sorry
A video was released by ih8sn0w on how to modify a certain file to do certain things, and people took it to the extreme, websites like this are idiots, people he was showing you what file to modify, he never said it would work right after, you have to jailbreak the firmware to install it after decrypting it.
http://www.sizzledcore.com/2010/04/10/install-iphone-4-0-beta-firmware-without-udid/
First off start researching before you post stupid things here is the reason why the method above does not work.
Some people claim to have enabled multitasking support without jailbreaking the iphone on a 3g by editing some files on it (bs)
Some people have claimed to be able to install the Beta 4.0 OS without their UDID on a dev account (bs)
I think these people are full of shit and heres why, I was curious about how people were making these assumptions and basically talked to someone about the subject.
<rcg> im just wondering if the iphone ipsw will accept an unencrypted rootfs to be installed
<xxxxx> rcg: You need to patch asr in the ramdisk to return true on the SHA1 check.
<xxxx> you then need to patch the kernel to boot the modded ramdisk with asr inside
<xxxx> which means you then have to patch iBoot, LLB, iBEC, iBSS, WTF
So folks this basically means that you have to jailbreak the firmware yourself in order to do what most people have claimed they have, thank you for joining this weeks episode of BULLSHIT