Semphore says that he has rewritten TinyUmbrella from the ground up, and has made it a lot more easier to use the tool.
If you’re new to the iPhone Hacking world, then here’s a recap to understand the importance of the release. As you probably know, Apple allows you to restore to the latest iOS versions only to prevent users from downgrading to an older iOS version, which would have made it easier to jailbreak the iOS device. For example: If Apple allowed users to downgrade their device, they could downgrade back to iOS 8.1.2, which can be jailbroken using TaiG and PPJailbreak.
Apple prevents this by stop signing the firmware files (by not providing SHSH blobs) for older iOS versions. Tools like TinyUmbrella allowed you to save the SHSH blobs, so you could use it to create (stitch) a pre-signed IPSW file, which could then be used to restore your device with an iOS version that Apple was no longer signing. However, Apple has closed the loophole that allowed users to use the SHSH blobs in newer devices (iPhone 4S and later) and also in iOS 7 or later. So you cannot restore to 6.x using SHSH blobs except on iPhone 4, iPhone 3GS, and iPod touch 4G (and iPad 2 to iOS 5.x if you have iOS 4.x and iOS 5.x SHS blobs).
Despite the lack of support for new iOS versions, it was considered a good practice to take a backup of the SHSH blobs, so if someone had discovered a way to hack the restore process in the future to again using the custom IPSW firmware file, then the SHSH blobs would come in handy, especially the current situation, where we’re eagerly waiting for the iOS 8.2 jailbreak.
The new version of TinyUmbrella now saves the SHSH blobs automatically for your device, and also gives you the option to save the ‘OTA’ SHSH blobs for all the known devices.
As you can see above, TinyUmbrella has saved the SHSH blobs for my iPhone 6 Plus for iOS 8.2 and iOS 8.1.3. It is because Apple is currently signing iOS 8.2 (which is the latest version currently) and iOS 8.1.3 (Apple tends to stop signing the previous version in a week or two).
The most exciting part of the news is that semaphore has indicated that it maybe possible to downgrade to older iOS version using the SHSH blobs. He has said that he will be updating the tool “with much more admirable features that many of you want. 🙂 Until then, Save your SHSHs!”.
If he can make it possible then it would be a major breakthrough, as the ability to downgrade to say iOS 8.1.2 (just an example) using a custom IPSW firmware file using the SHSH blobs, will ensure that the iOS device can always be jailbroken. It would be a good workaround until a jailbreak for the latest iOS version is released.
You can download TinyUmbrella using this download link (click on the download link in the right sidebar under Downloads/Links).
The possibility of an option to downgrade iOS version would be a major breakthrough for the jailbreak community. Let us know what you think in the comments.