Grassroots Social Networking: Where People have Agency over their Personal Information and Social Graph

Offering an architecture for social networking in which people have agency over their personal information and social graph is an open challenge. Here we present a grassroots architecture for serverless, permissionless, peer-to-peer social networks termed Grassroots Social Networking that aims to address this challenge. The architecture is geared for people with networked smartphones -- roaming (address-changing) computing devices communicating over an unreliable network (e.g., using UDP). The architecture incorporates (i) a decentralized social graph, where each person controls, maintains and stores only their local neighborhood in the graph; (iii) personal feeds, with authors and followers who create and store the feeds; and (ii) a grassroots dissemination protocol, in which communication among people occurs only along the edges of their social graph. The architecture realizes these components using the blocklace data structure -- a partially-ordered conflict-free counterpart of the totally-ordered conflict-based blockchain. We provide two example Grassroots Social Networking protocols -- Twitter-like and WhatsApp-like -- and address their security (safety, liveness and privacy), spam/bot/deep-fake resistance, and implementation, demonstrating how server-based social networks could be supplanted by a grassroots architecture.