That's cool. I hadn't heard of that, before. I had a related idea for achieving plausible deniability of the key in full disk encryption or similar scenarios. The password would be derived from the position of sensitive, yet innocuous, elements on the device, ensuring that the seizure of the device would likely corrupt this relationship. For instance, a series of N-sided dice could be placed in specific positions on top of the device (in the case of a desktop computer, perhaps), and the password derived from their sequence. Consideration must also be given to the possibility of the device being photographed—likely from a single angle—before being moved. So, the dice would be positioned to include some amount of occlusion. Any dice-based algorithm would need to ensure the search space for the resulting key was sufficiently large.