> everyone who uses it would install an app to use it Exactly. Meaning you must have key management. > Also in response to the earlier comment: the app could

> everyone who uses it would install an app to use it Exactly. Meaning you must have key management. > Also in response to the earlier comment: the app could provide a friendly interface for generating keys which doesn't require the user to know the technical details. They would just have an "identity file" that would be stored on the app, with options to copy it to a usb stick etc. You are repeating history. PGP and many similar products have provided exactly this for end-user encryption of email for more than two decades. Not one has gained mass adoption. You cannot make a system that relies on the user to understand anything at all about key management, no matter how friendly the interface. "I will write a new program that makes email encryption easy!" has long been a joke/cliche. Key management is a problem that must be addressed with something more substantive than just yet another new interface tacked on top of the same old ideas. I can't even get intelligent developers to manage SSH keys properly. They lose them constantly, or forget their passphrases (if I can even get them to use a passphrase). There is absolutely no hope of making a service anywhere near as popular as Twitter that adds the friction of key management.