As we move towards and iOS 5.0.1 untethered jailbreak, the iOS community knows that Apple will soon release iOS 5.0.2 to cover the tracks it left uncovered. This would mean that once you upgrade to iOS 5.0.2, you may be unable to jailbreak the devices, at least for some time. So in case you’d want to restore to older version, Cydia’s Saurik is working on a hack that will let you do just that.
So how is this done? This is done by caching SHSH Blobs. SHSH Blobs are the signature files which Apple’s servers use to verify when you try to downgrade from a latest version of iOS to an older version. If the verification isn’t complete, you can’t downgrade and so, have to use a much more secure iOS which, unfortunately, also means less room for iOS hacks and exploits.
But by caching SHSH Blobs, this process by Apple’s servers can be verified. And the restore can be accomplished through an alternate server which has the SHSH Blobs cached on it already. In this case, Cydia’s founder, Saurik is caching the SHSHS Blob files and his server can then be used to bypass Apple’s restore restrictions.
How is this useful?
Once you upgrade to a future iOS version, for example iOS 5.0.2, Apple will most probably add more security to it. This may mean that for some time, we won’t be able to find a good jailbreak solution for the iOS 5.0.2. Some of you will, in eagerness or by accident, upgrade to the new version and once you find out you can’t jailbreak, you may want to downgrade again. And that may be a problem through Apple servers. At such a time, such a hack which allows restoring without verification will come in handy for all such users. For now, Saurik is cahing the files and hopefully, by the time the next iOS version is released, his server will be all set for the hack.
Image courtesy adria.richards.