Recently, we learned that software developer Semaphore, the guy behind TinyUmbrella, was in the process of updating the famed SHSH blob-saving tool, which, once upon a time, would facilitate the downgrading of iOS devices to previous firmware versions. Having been left to fester for a couple of years, it was suspected that iPhone and iPad downgrading was a forgotten art, but thanks to Semaphore’s revelation that he would be rebuilding TinyUmbrella from the ground up, we now know better. A beta version of the new TU has now been released supporting the recent iOS 8.1.3 along with the current iOS 8.2.
SHSH blobs don’t sound too special, but if you ever wanted to downgrade your device, they could prove to be a godsend. In layman’s terms, they contain device-specific information which can be used to sign IPSWs of old firmware versions, allowing you to downgrade even after Apple has stopped signing them. TinyUmbrella creates a false Apple server that gives your device the green light to install any build that you have saved SHSH blobs for. At least, that’s how it used to work before Apple patched the loophole from its end.
Right now, it would seem that Semaphore is still working on getting TinyUmbrella to work its magic; this being, to offer seamless downgrading using cooked-up IPSWs. But the good news is that you can download the new version and save your blobs right away, meaning that when it does become possible to downgrade, which should be soon, you’ll have the necessary files backed up and will be able to pick and choose what firmware you wish to revert to.
If you’re a jailbreaker, and or have ever had the desire to downgrade your device, then we’d recommend grabbing the new TU right away and saving your SHSH blobs. If you happen to be on iOS 8.1.2, and still jailbroken, here’s the advice given by Semaphore on Twitter:
The importance of SHSH blobs presently was emphasized in another tweet which Semaphore sent out earlier.
To elaborate, even if you do save your SHSH files on iOS 8.1.2, downgrading is not yet possible, and as such, you’ll want to stick with iOS 8.1.2 even after you have stored the blobs for safekeeping.
The same blob-saving advise goes out to iOS 8.2 users. Though there isn’t a jailbreak available yet for Apple’s latest mobile firmware, but if later on one is released and the prospect of downgrading becomes possible once again, then the SHSH blobs you saved today could prove to be a lifesaver later on.
If you’re running an iPhone 4s or a newer iOS device, then saving SHSH blobs won’t do you any good for now, except for the purpose of safekeeping. But if you’re running hardware prior to the iPhone 4s, that is, the iPhone 4, 3GS or even the 4th-gen iPod touch, then you can still downgrade to iOS 6.x right now, provided you have the SHSH blobs saved. iPad 2 users can also get in on the action, and can downgrade to iOS 5.x if they have blobs for iOS 4.x saved with your somewhere.
As per a blog post on the beta, the new release is a little rough around the edges, so anybody using it should expect to encounter a bug or two along the way. With that said, Semaphore has promised that further updates in the near future will add a bunch of new and exciting features, and given what we’ve already been treated to from the likes of Pangu and TaiG, it appears that the iPhone hacking community is in very good shape just now.