An other great news by Posixinja that Greenpois0n is working on untethered Jailbreak iOS 4.2.1. And good news is that in new version of Greenpois0n Jailbreak untethered iOS 4.2.1 you do not require to save blob SHSH firmware 4.2 beta 3. an updated version of the jailbreak will be soon released as they finish to adding the new sandbox patches.
iPhone Dev Team member MusclerNerd has tweeted an article which is about Jailbreak Monte Porting of success, the technique to iOS 4.1, it is now possible to untethered jailbreak your iDevice which is using iOS 4.2.1 by using Redsnow 0.9.7 and by using iOS 4.1 firmware and hashes.
This jailbreak monte has very advantages you can also ported to upcoming firmwares releases that is iOS 4.3 without any kind of difficulty and this will enable users to untether the iOS 4.2.1 jailbreak on iPhone, iPad and iPod touch without having 4.2b3 SHSH blobs saved on Cydia. and this is next plan of iPhone Dev Team.
With Redsnow 0.9.7 you can untether your iOS 4.2.1 jailbreak using iOS 4.1 IPSW files.
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