iPhone Backup my iPhone's signed data?

[AMG1978]

I am just back to owning an iPhone after a few years of having an Android. I remember on iOS 5 or iOS 6 when I had an iPhone 5, there was a way to back up the signed cert that apple put on my exact device for that exact release of iOS, so that once you upgrade, and apple stops signing, you could still revert. I am on 10.1.1 now and thinking that when 10.2 comes final, I will prob go to that, *but* if there's that rare chance that later a jailbreak comes out for 10.1.1 but cant work in 10.2, I'd love to be able to simply go back to 10.1.1.

Is this still possible what I describe above? How?
Thanks.

 

[eyoungren]

You've missed some important stuff.

Apple got rid of SHSH blobs with iOS 7 and moved entirely to APTicket. No one has been able to crack that yet - at least with 64-bit devices.

You can still save out blobs if you want (don't ask me how, not something I ever pursued) for the day that they may become relevant again. But as of right now there's no way for any 64-bit device to downgrade/upgrade.

It's possible with 32-bit devices (iPhone 5 and below) but they have to be jailbroken first and if you don't have blobs you have a limited selection of iOS versions you can downgrade to, one of which is 8.4.1 which does not have a jailbreak.

PS. Here's where things all started to go sideways on this: http://www.saurik.com/id/15

 

[Applejuiced]

Yep, unfortunately those days are over.
Apple has a way stricter and harder iphone restore verification method that doesnt allow the "man in the middle" exploitation we could do before with saved replay of shsh blobs.
I sure miss those days.