iOS 10.3.3 OTA Update Will Apparently Be Signed For Life On iPhone 5s And Other A7 Devices
It’s been relatively common knowledge for a while now that Apple kept signing iOS 10.3.3 for iPhone 6s for quite a bit longer than usual. And now, it has been pointed out by Jato_BZ on Twitter that the Cupertino-based company is still signing iOS 10.3.3 for iPhone 5s and likely a slew of other A7-based devices which will be great news to hardware owners who have a vested interest in the jailbreak community.
Jato_BZ, who works as a reverse engineer and enjoys tinkering in this type of environment, has found that his iPhone 5s was able to present him with the availability of iOS 10.3.3 OTA update through the official Software Update section in the native Settings app.
Normally, when taking a device and opting to upgrade, Apple would only serve up the latest publicly available version of iOS for that device, which in the case of iPhone 5s would be iOS 11.1.2. However, this device, which was running iOS 7.x, was able to show iOS 10.3.3 as an available software version proving that Apple is still signing the firmware from its end.
The hypothesis here is that if Apple is still choosing to serve iOS 10.3.3 to the iPhone 5s, then the same should be available for other A7-based devices due to an issue which prevents iPhone 5s and other devices on the same A7 architecture upgrading directly to iOS 11 from iOS 7 without first sitting on iOS 10.x.x. We don’t have any official release why this problem actually exists but those affected devices need to physically move to iOS 10.x.x before they can upgrade to iOS 11, which is likely the main reason why Apple will continue to sign iOS 10.3.3 indefinitely for these devices.
For a lot of us, that doesn’t really mean anything or offer any immediate benefits. However, for jailbreaks, it means that owners of those devices can move to iOS 10.3.3 and wait patiently in the hope of a jailbreak becoming available for that firmware.
It’s important to note though that only iOS 10.3.3 OTA appears to be signed, not the IPSW, which means if you are already on iOS 11, you can likely not downgrade to 10.3.3. This will only be useful if you are sitting on a firmware as low as iOS 7 and want to upgrade to 10.3.3 via OTA. Only then will you be able to get your device on iOS 10.3.3.
Currently, the latest public jailbreak for 64-bit devices only supports as far as iOS 10.2.1. The fact that iOS 10.3.3 is still being signed for iPhone 5s, and presumably some other devices, means that anyone who is sitting on an older firmware like iOS 7 will be able to upgrade to iOS 10.3.3 via OTA update method, if, and when, a jailbreak is released for that firmware.