With every new iOS firmware update Apple tries to make impossible the option to downgrade iPhone to older iOS versions using iTunes (in case you have saved SHSH blobs). There are news that Apple is about to close SHSH blobs and APTicket exploits. I think that there is no need to tell you that if you want to downgrade iOS 6, iOS 5.x versions you need to have backed up SHSH blobs of the firmware version you try to restore your iPhone's firmware. There are several methods to save these blobs using such tools as TinyUmbrella, Redsn0w or even Cydia. But what is really important is to save SHSH blobs and APTicket before Apple stops to sign them. If you come up with it you can successfully perform downgrade. But latest news from iPhone Dev Team points that: “that’s all about to change”. Note: Now you can use TinyUmbrella 6.0 to save iOS 6 SHSH blobs and APTicket for the future; just in case. You may know that APTicket and SHSH blobs exploits play an important role in iOS downgrade. But when Apple launched iOS 5 beta the things changed. The role of APTicket changed. Now Cupertino company use it as BBTicket. The LLB (Low Level Boatloader) and iBoot platforms of the boot routine are now being refined to rely on the validity of the APTicket, which is unique after every restore or downgrade. This APTicket validation takes place at each boot, not only during downgrade. The reason is that Apple has crypto keys to accurately indicate the per-restore APTicket which means that no one can rewrite or change it. As I said before it concerned only iOS 5 and the following versions. Apple can open or close APTicket sighing window for iOS you want to downgrade like they do with BBTicket. So you better hurry up because soon you will not downgrade iOS 6 using Cydia server for Gevey Sim unlock any more. However tethered jailbreak will be always possible for the gadgets that support geohot’s exploit limera1n. Also if you have saved SHSH blobs of lower firmware than iOS 5, the downgrade will be possible too but soon you will have to use older versions of iTunes. So if yor iPhone is running latest Apple iOS you can always use this guide to jailbreak iOS 6 tethered and then install Cydia but as you see the jailbreak will be tethered. As for untethered iOS 6 jailbreak, pod2g and other hackers are working on that but no one knows when we will see it. But, in general, it is really bad news and Apple will really close SHSH blobs and APTicket exploits soon. According to developers, Cupertino company “stepped up their game” in beta versions. Also developers try to reassure us that it can be possibility to circumvent these limitations with APTicket and SHSH blobs. Stay tuned with us for more information about closing exploits in SHSH blobs and APTicket. Via