It’s common practice for the Cupertino-based tech company to unsign older software sometime after a newer gets released. Doing so facilitates (sometimes involuntary) software upgrades, which ensures that the majority of iOS device users take advantage of the latest new features, bug fixes, and security improvements.
Another reason Apple foils software downgrades on its iOS device lineup is to thwart jailbreaking. Apple’s frequent software updates often contain security patches for exploits that are used in jailbreak utilities, and as you might come to expect, Apple doesn’t want you downgrading to run these hacks on your device.
It’s worth noting, however, that the brand-new checkra1n jailbreak utilizes a bootrom exploit called checkm8 on A5-A11 devices, up to and including the iPhone X. That said, this jailbreak can’t be patched with software updates, and in this case, software signing is particularly irrelevant.
Where this does make a difference, however, is in the case of handsets that aren’t supported by the checkm8 bootrom exploit, such as the likes of A12-A13 devices…
Jailbreakers sporting the aforementioned handsets rely heavily on evading software updates and downgrading their firmware when they get the chance. This is because jailbreak tools like Chimera and unc0ver can be easily patched via software updates, and this is why these tools are updated so frequently with support for new tfp0 exploits – to add support for new versions of iOS that patch previously-used exploits.
If you have an A5-A11 handset in your possession, then you can probably shrug this news off. On the other hand, those sporting A12-A13 devices with any intention of jailbreaking in the future will want to do their best to refrain from updating their firmware. As unc0ver jailbreak lead developer Pwn20wnd once famously said, it’s best for aspiring jailbreakers to stay on the lowest firmware possible whenever they can for the best odds of an updated jailbreak.
As always, you can check the software signing status for your device at the ever-so-useful online IPSW.me utility.
Are you upset that iOS 13.2 is no longer signed by Apple? Discuss in the comments section.