It wasn’t that long ago we told you that the iOS 11.2.5 Secure Enclave Processor (SEP) was thankfully compatible with iOS 11.1.2. That discovery was great news for the jailbreak community as it meant that it was possible to downgrade from iOS 11.2.5 to iOS 11.1.2 with the necessary SHSH2 blobs in order to jailbreak using a tool like Electra.
Great news at the time but not so great news now with iOS 11.3 on the horizon as iOS 11.3 beta 2 SEP has been found to not offer compatibility with jailbreakable firmware versions.
Where the iOS 11.2.5 Secure Enclave Processor (SEP) was concerned, users who had SHSH2 blobs saved for iOS 11.1.2 were able to use the latest version of the extremely useful FutureRestore tool to downgrade directly to that version of Apple’s mobile platform. This was because the SEP of iOS 11.2.5 was compatible with that of iOS 11.1.2.
That process was invaluable for those who had moved to iOS 11.2.5, either advertently or inadvertently, and who had their SHSH2 blobs saved, and who wanted to go back from where they came in order to liberate the device using Electra.
It seems that the change in SEP of beta 2 of iOS 11.3 is relatively new because iOS 11.3 beta 1 SEP was compatible with iOS 11.0 through iOS 11.1.2. This may seem like somewhat of a setback but it’s definitely more of a bump in the road than anything major.
Currently, it’s only registered developers and public testers who can download and install iOS 11.3, which means that it isn’t widely distributed as yet. Apple is currently still signing iOS 11.2.5, so for those who may be on the iOS 11.3 beta, and who feel like this could be a problem for them going forward, and, of course, who have iOS 11.1.2 SHSH2 blobs stored, it could be worth downgrading back to iOS 11.2.5 right now.
Source: redmond pie