Actually Canon makes their SDK freely available and while they don't let you fork the operating system there's an open-source alternative called Magic Lantern that works very well on most of their DSLR range and adds a lot of functionality (as well as providing a lot of reverse engineering info on their hardware through the site). Canon hasn't officially blessed this, but they haven't obstructed them in any way.
The main problem with adding encryption would be that photos and video can consume a lot of bandwidth, and the bandwidth inside a digital camera is limited, as is the processing power. It would make more sense to put the encryption directly on the media card, similar to the fashion in which Eye-fi cards include a tiny CPU and web server to automatically offload the content to a trusted network.
The main problem with adding encryption would be that photos and video can consume a lot of bandwidth, and the bandwidth inside a digital camera is limited, as is the processing power. It would make more sense to put the encryption directly on the media card, similar to the fashion in which Eye-fi cards include a tiny CPU and web server to automatically offload the content to a trusted network.