It was all made out of parts with standardized interfaces, so components could be consumer equipment. I also used the same software on my laptop to encrypt it.

It was all made out of parts with standardized interfaces, so components could be consumer equipment. I also used the same software on my laptop to encrypt it. It's nothing fancy, just using the dm-crypt kernel module and any kind of hardware security module that talks PKCS#11 (which is all of them); On my laptop I just used my existing smartcard (which I used to login to the system and remote systems). The disk header was just text occupying the first 4MiB of the disk in 2 circular buffers similar to LVM (though 2 copies for redundancy).