Privacy-Preserving Spam-Protected Gossip-Based Routing.

WAKU-RLN-RELAY is an anonymous peer-to-peer gossip-based routing protocol that features a privacy-preserving spam-protection with cryptographically guaranteed economic incentives. While being an anonymous routing protocol where routed messages are not attributable to their origin, it allows global identification and removal of spammers. It addresses the performance and privacy issues of its counterparts including proof-of-work and reputation-based schemes. Its light computational overhead makes it suitable for resource-limited environments. The spam protection works by limiting the messaging rate of each network participant where rate violation results in financial punishment. We deploy the novel construct of rate-limiting nullifier to enforce the message rate limit. We provide a proof-of-concept implementation of WAKU-RLN-RELAY to prove the efficiency and feasibility of our solution.