logoalt Hacker News

codethiefyesterday at 7:22 PM1 replyview on HN

> The approach used by desktop operating systems with TPMs is awful and makes security worse in a lot of ways rather than better. It's not at all the same thing, similarly to how what the desktop world calls secure boot is not a serious or complete implementation of it and doesn't provide nearly any useful security properties to end users unlike iOS or AOSP.

Interesting. Could you elaborate? I always thought that Secure Boot is reasonably secure (provided you can set it up in the first place).


Replies

grapheneostoday at 8:04 AM

The standard UEFI Secure Boot used with traditional Windows and traditional desktop Linux is an incomplete and insecure implementation of secure boot. It doesn't verify the vast majority of the OS, nearly always lacks an unbroken chain of trust from the hardware, does not verify all of the firmware and lacks downgrade protection for both most of the firmware and the OS. In the typical setup, it trusts an enormous number of keys and software. It barely provides any useful security properties.

Secure boot was widely used as a term prior to the UEFI usage of the term including many much more meaningful implementations. The term verified boot refers to the same concept but avoids it being confused with solely verifying a late stage bootloader and OS kernel from UEFI firmware.