> Why would it not be possible to create a system that required several manual and offline steps No matter what "offline" and "manual" steps you propose, they

> Why would it not be possible to create a system that required several manual and offline steps No matter what "offline" and "manual" steps you propose, they can be made online and automatic after a one-time compromise of the system. And if a single system is protecting the secrets of literally everyone, the incentive for compromising that system is unlimited. There's no attack too impractical when the stakes are so high.