[Cryptech Tech] dev-bridge board

[Jacob]

On 12/18/2015 3:58 PM, Randy Bush wrote:
>> I saw the recent discussion regarding the USB interface.  Not really
>> aware to the constraints and choices made earlier, so excuse my
>> ignorance, but why do you guys use the FT232 (or consider a MPU-based
>> USB interface) when the main CPU STM32F429 has 2 native USB interfaces
>> available - one full speed and one high speed?
>
> this is a security device.  usb is a big hole.  we want i/o to go
> through as small a hole as possible.
>
> randy

I know nothing about USB protocols, but I understand that USB is a 
security hole in general just because recent OSs happily process 
whatever is fed to them through that port. But with the Alpha board, you 
are in control what to do with the port data coming in or going out - 
just like if it comes through the UART.
However, if you use USB libraries, then the situation is a bit more muddy.