Ah, so with Android, you can enable lockdown mode. This adds a button within the power menu that, when pressed, disables biometrics until your password is entered.
This is the best compromise for me as entering my password whenever i want to look at my phone would be unwieldy. i could drop the security to a pin or something, but i prefer my phone to be as secure as possible.
Sorry if this get really off topic.
How useful would such data ever be? From my understanding, the data is useless, even if they get the password later on, since you need device specific chips to successfully read / decode data from the memory modules. (Why repair people de-solder chips from an old phone and implant them into donor phones to get their data back… even though the customer knows the passwords)
…this would be in a naively world where big tech didn’t already hand over securitu backdoors to the government
It would depend on the device and how the encryption is implemented. For any modern phone using the built-in encryption, the key will be stored in some sort of secure element and (barring secret exploits or backdoors) you would need the chip as well as the password and storage backup.
That said, there are companies that make a lot of money selling secret exploits, so they may just decrypt the backup without needing your password at all.
Encryption that is applied at an app level where the password is used to derive the key or on a PC where someone chooses not to use the TPM would be recoverable if the password is exposed after a backup is made.