Hacker Tihmstar announced a solution to downgrade the operating system on the iPhone or iPad version, which no longer signed by Apple. For this purpose the developer is preparing a utility called Prometheus.
The program will allow you to browse for the iOS version (downgrade or upgrade) that stopped signing Apple. The main condition for a successful transition – the availability of previously saved SHSH blobs.
SHSH blob is a digital signature file, which Apple checks the version of iOS on the device. Deliver earlier operating system on iPhone and iPad not because it’s against the rules of the company. To do this, send a request to a dummy server, which will return in iTunes need a digital signature (previously stored), and will allow you to perform the installation.
Important point: to use the Prometheus will need certificates in the new format shsh2. The developer has created a special server that mimics the official epplovskih and allow you to upload the SHSH blobs for the device. This is done using a free utility Tsschecker available for macOS, Windows and Linux. If you have a saved certificate, everyone will be able to downgrade to an earlier iOS version.
If the user has no saved SHSH blobs, it will update your device to new iOS, then not being able to roll back the firmware, it will lose the jailbreak. In order to avoid this, you need to save a digital signature.
First and foremost, the decision may be true for those who are waiting for iOS 10.1.1. Learn about how to save SHSH blobs using Tsschecker at the video.