Ever wondered why you cannot just go back to an older jailbreakable iOS firmware version instead of being stuck on an unjailbreakable version ? Well, it isn’t possible currently, but was possible some time ago. It is a public fact that Apple does not quite like the concept of jailbreaking, which is why it keeps patching every jailbreak that comes out every now and then. In Oct 2015 , Apple’s iOS 9.1 firmware patched the Pangu 9 exploits, while Apple had previously patched the iOS 8.4 jailbreak with the iOS 8.4.1 release. Only if it was possible to downgrade to older versions of iOS, jailbreaking would be possible any time.
Image : TinyUmbrella Windows Download
Here’s what happens. After a new iOS update is released, Apple stops signing the previous iOS version within a week. For instance, signing window for the jailbreakable iOS 9.0.2 was closed after almost a week of the release of the unjailbreakable iOS 9.1. Apple stops providing SHSH blobs for those versions that are not being signed any more, thus preventing us from downgrading. Previously, during the time of iOS 5, users were able to save SHSH blobs using the TinyUmbrella tool. Those blobs could then be used to stitch pre-signed IPSW firmware files, which could be used again and again whenever you wanted to jailbreak an iOS version that isn’t being signed by Apple.
Image : Tinyumbrella Running in Windows
However, that loophole which allowed the use of SHSH blobs for downgrading was closed by Apple in newer devices like the iPhone 4S and later. The loophole was patched for iOS 7 and above, so users can’t use the SHSH blobs for restoring to iOS 6.x unless they do it on iPhone 4, iPod Touch 4G, iPhone 3GS, and possibly the iPad 2 also. However, you might have heard jailbreakers advising you to keep saving SHSH blobs. Because a downgrade method might come up in the future, and those blobs might become useful again.
Even though TinyUmbrella currently can’t do anything more than help you save your SHSH blobs, it will still be a good practice on your part to back up the blobs. It might prove useful to you in case someone comes up with a downgrade method in the future.
TinyUmbrella has got updated recently for supporting iOS 8.2 or lower, and Semaphore, the developer, says that it might be possible that users can use SHSH blobs for downgrading to an older iOS version.
If you use jailbreaks a lot and want to make sure that you can downgrade to an older, jailbreakable iOS version in case a way to downgrade comes up in the future, you should download TinyUmbrella right now to save your SHSH blobs.