Following the natural process of what has been seen for some time, Apple stopped signing iOS version 15.7 – just as it did with version 16.0.3 of the system last Monday.
With the release of versions 16.1 and 15.7.1, the company removed the possibility for its users to downgrade, which is the process of reverting the system update to a previous version. Thus, the previous numbers of iOS start to become obsolete.
As a result of the move, anyone who tries to restore their devices to version 15.7 and earlier will get an error message.
Generally, the downgrade process is highly sought after by those looking to jailbreak their devices in order to circumvent rules established by Apple, installing unauthorized software from third-party app stores.
With the removal of the signature, Apple tries to inhibit – in an incisive way – this movement, using the justification of not wanting to expose its users to an environment of vulnerabilities, in addition to avoiding the fragmentation of the amount of active firmware.