Insider Attack Resistance
https://android-developers.googleblog.com/2018/05/insider-attack-resistance.html [android-developers.googleblog.com]
2018-06-01 17:37
To mitigate these risks, Google Pixel 2 devices implement insider attack resistance in the tamper-resistant hardware security module that guards the encryption keys for user data. This helps prevent an attacker who manages to produce properly signed malicious firmware from installing it on the security module in a lost or stolen device without the user’s cooperation. Specifically, it is not possible to upgrade the firmware that checks the user’s password unless you present the correct user password.
source: HN