Ooo. This maybe what is needed to build that. The properties described in the background are perfect for storing encrypted federated social network posts.
social.coop is a a coop-run corner of the fediverse, a cooperative and transparent approach to operating a social platform. We are currently closed to new memberships while we improve our internal processes and policies, and plan to re-open to new folks when that work is complete. [9/2/2018]