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This confused me. How does these unique signatures work and how does it improve boot security?
by panpanna 6y ago
This confused me.
How does these unique signatures work and how does it improve boot security?
- ghostpepper 6y agoIIRC the general idea is that the pin code or password is required to be entered when an update is requested, which unlocks a key pair. The public key is included in the update request, which is then sent to Apple. Apple sends back a download that is signed in a way that the firmware can verify, and Apple guarantees never to send another download in response to that exact request. This protection also relies on the secure enclave never authorizing the installation of an unsigned OS update.
- runeks 6y ago> Apple sends back a download that is signed in a way that the firmware can verify, and Apple guarantees never to send another download in response to that exact request. Interesting! Thank you for the detailed explanation.
- dbuder 6y agoEach device has a code, the manufacturer knows the code for each device and what device is being updated and the firmware is modified to need that code to update/work. It is more secure because if you crack the code you only have it cracked for one device - which is still bad but it is less likely to lead to an exploit that bricks all the devices.