How do your users know which Public Key belongs to someone they want to communicate with?
Put it in their profile. Seriously that's it. You can use a profile metadata field if you want to be formal about it.
Why would you need a history of what keys were whose?
Put it in their profile. Seriously that's it. You can use a profile metadata field if you want to be formal about it.
Why would you need a history of what keys were whose?