The Matrix AI team has been developing Polykey, a distributed peer-to-peer secret sharing system. It is intended to manage secrets, passwords, API keys for both humans and machines.
There is a problem that is common to databases , user interface , programming languages and pretty much everything that involves state in more than 1 location. It's called the "view update problem". Or in a more general sense: (Bidirectional) Model Transformation . In the functional programming world, this is modelled via a concept called Lenses. It turns out that this elegant idea, is a great way to model distributed system architectures and the pattern appears in many contexts.