Who issues the private keys? What happens if the keys are compromised? What happens to the debt if a key is lost? How do you migrate older debt to the new syste

Who issues the private keys? What happens if the keys are compromised? What happens to the debt if a key is lost? How do you migrate older debt to the new system? How would this solve the issue of proving the person you are talking to actually owes the debt? There are soooo many questions and things to figure out in such a big and complicated system. It's easy to criticize, especially when you aren't actually responsible for execution.