>>907103
>vulnerable to things like PowerHammer and sigint attacks
I haven't heard of those before, but it seems those attacks require compromising the target machine first. If not, you can just run random computations to add noise to the power consumption.
>For two passwords are just as vulnerable to social engineering attacks as that library of books is.
Multiple passwords is to have the ability to revoke access from certain individuals who no longer need access to the encrypted data or who need to have their keys cycled. If there is a leak, you know who exactly it came from.