This principle is the major differentiator between Casa and high-security DIY protocols. There is a history of security software that fails to achieve widespread adoption due to the difficulty of using it compared to less secure alternatives. For us, usability is a key component of security, not an afterthought. Again, it doesn’t matter how secure a system is if nobody uses it.
Another reason why usability matters is that cryptographic systems often have “sharp edges” where mistakes can lead to lost data or loss of privacy. In security software, sharp edges are dangerous and should be minimized. It should be hard or impossible for users to shoot themselves in the metaphorical foot.
Our system can’t remove all danger from our users. For example, 3-of-5 Key Shield can withstand two keys lost, but not three. When users do approach a dangerous situation, we warn them and provide mechanisms to recover with the goal of preventing a catastrophic loss.