The USB armory from Inverse Path is an open source hardware design, implementing a flash drive sized computer.
The Aegis Secure Key is ready to go right out of the box. It does not require any software or drivers to be installed and is compatible with PCs, MACs, Linux and embedded systems. The Aegis Secure Key uses drag and drop encryption, is plug and play ready and can be used with any off the shelf backup software. The next step requires you to input a password in order to be able to access content, and even add a hint. Data can be encrypted usb protect for enhanced security, by accessing the Details tab. Once the drive is secured, you need to provide the correct security key in order to be able to view, add or modify data. The problem is, assuming there’s no driver vulnerabilities, is that you still have to go through USB channels to actually perform the attack. Meaning that a hybrid mass storage and HID device could insert key strokes to open and execute files it stores.
Even when a modest message arives from a supposedly trusted source, you still have to verify what you get, not to do so is asking for trouble. Afterall the credentials could have been stolen or the person subject to duress. Dealing with this is difficult if not impossible usb access control unless certain precautions are in place prior to the trust relationship being established. Some of these precautions are purely human in nature, as one gangster was heard to remark, he would only trust people who had a lot lot more to lose than he did.