Depends on your definition of trust. But yes, if you assume this device is treated as malicious at both ends - just like an unfiltered internet connection, but

Depends on your definition of trust. But yes, if you assume this device is treated as malicious at both ends - just like an unfiltered internet connection, but 10x worse - and that the client software that is doing the load/verification, or unload/verification is doing decent input validation, and your assumption that the user is doing their own encryption prior to transfering it to the device, I agree.