Quote: "Android Protected Confirmation is deprecated due to the high
support/maintenance cost for Android device makers and low adoption rate
among app developers. APC requires Android device makers to have a
substantial amount of device-specific UI code running in the trusted
execution environment. That has proven to be expensive to maintain and
non-scalable, as there cannot be a single implementations device makers
can share or use as a reference. Additionally, app developers have not
adopted this feature, as the Android platform offers other mechanisms
for authentication a user's intent. These mechanisms, such as
authentication-bound Keystore keys, are less secure than Trusted UI, but
are more wide-spread. While we explore alternatives to APC that are
viable to the device makers ecosystem, we sunset the APC API."
Oh damn, I missed that, thank you. I could see how it was a very expensive thing to maintain for an effectively Pixel-only feature.
Still, I think this was one of the most ambitious and user-beneficial implementations of trusted computing I've seen so far, in that it theoretically safely allows a completely rooted/user-owned device to still participate in things like online banking or e-government transaction authorization. I hope it'll return in some form.
Quote: "Android Protected Confirmation is deprecated due to the high support/maintenance cost for Android device makers and low adoption rate among app developers. APC requires Android device makers to have a substantial amount of device-specific UI code running in the trusted execution environment. That has proven to be expensive to maintain and non-scalable, as there cannot be a single implementations device makers can share or use as a reference. Additionally, app developers have not adopted this feature, as the Android platform offers other mechanisms for authentication a user's intent. These mechanisms, such as authentication-bound Keystore keys, are less secure than Trusted UI, but are more wide-spread. While we explore alternatives to APC that are viable to the device makers ecosystem, we sunset the APC API."