Define communication within a closed group of people who know each other.
This idea is already implemented in PGP, but public key directories are very rare and hard to maintain. For server-to-server communication X509 certificates are perfect and the common login problem can easily be solved by client certificates, as any known system comes with a set of trusted CA's and the certificate stores.
But security has a keyboard to chair interface bottleneck, where the punks sits and does not care about anything.
Lets define a lazy system for lazy people.