Grassroots Social Networking: Serverless, Permissionless Protocols for Twitter/LinkedIn/WhatsApp

Offering a viable alternative architecture to centrally-controlled global digital platforms for social networking is an open challenge. Here we present a grassroots architecture for serverless, permissionless, peer-to-peer social networks termed grassroots social networking. The architecture is geared for roaming (address-changing) agents communicating over an unreliable network, e.g., smartphones communicating via UDP. The architecture incorporates (i) a decentralized social graph, where each member controls, maintains and stores only their local neighbourhood in the graph; (ii) member-created feeds, with authors and followers; and (iii) a grassroots dissemination protocol, in which communication occurs only along the edges of the social graph. The architecture realizes these components using the blocklace data structure - a distributed partially-ordered counterpart of the replicated totally-ordered blockchain. We provide two example grassroots social networking protocols-Twitter/LinkedIn-like and WhatsApp-like-and address their security (safety, liveness and privacy), spam/deepfake resistance, and implementation, demonstrating how centrallycontrolled social networks could be supplanted by a grassroots architecture.