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> Real devices are fused to prevent downgrades. Not quite, to install a version of iOS it must be signed by Apple, and Apple stops signing old versions soon af
by CamJN 6y ago
> Real devices are fused to prevent downgrades.
Not quite, to install a version of iOS it must be signed by Apple, and Apple stops signing old versions soon after releasing a new one. Further you need to put the phone in recovery mode to install a lower version because the UI simply won't do it.
You may be thinking of game consoles, which use fuses to prevent downgrades.
- g_p 6y agoThanks, I was thinking of the server-side AP Token system (i.e. the signed per-device authentication tags that confirm the firmware is up to date and able to be installed), but then ended up describing the Nintendo Switch fuse system. Indeed, in the past I believe people have used SHSH blobs to successfully downgrade, and also if Apple misconfigured their signing server to approve older versions, people have successfully downgraded during the window created due to the misconfiguration.
- saagarjha 6y agoApple's devices have fuses, too, but they ensure that you boot something signed by them.