My goal is to find a USB stick with hardware encryption in order to access the APIs and unlock the partition with a password. The difference between a normal USB stick with hardware encryption is that the pen drive should be unlocked when the computer boots in order to start the OS inside the stick.
Since I have to be able to boot from any computer and use the stick as a "portable guest computer," I need a minimum size of 64GB and good read/write performances, so USB3 should be a good starting point I suppose.
The hard part is that I need a pen drive that will let me use the encryption APIs in order to create and modify from the OS the password.
I don't have a budget for this phase. I just want to create a sort of prototype, test it and try to hack it in order to see if it can be a valid encryption solution.
* EDIT 2 *
The system will work in this way, it's not an hypothesis or a project. We have already done something similar with Software encryption, but we need something more secure (that's why I'm looking for hardware encryption):
1) The computer boots and there will be a password input then two passwords will be available:
1.a) First password -> login into the OS
1.b) Wipe password -> destroy everything
The key needs 2 partitions, one for the system restore and one for the OS. Me and some other people are working on the kernel in order to make it bootable everywhere with multiple OS's (linux, Windows 10 mostly).
For security purposes we need a very specific hardware with AES 256bit hardware encryption and so on