VOUTE-Virtual Overlays Using Tree Embeddings.

Friend-to-friend (F2F) overlays, which restrict direct communication to mutually trusted parties, are a promising substrate for privacy-preserving communication due to their inherent membership-concealment and Sybilresistance. Yet, existing F2F overlays suer from a low performance, are vulnerable to denial-of-service attacks, or fail to provide anonymity. In particular, greedy embeddings allow highly ecient communication in arbitrary connectivity-restricted overlays but require communicating parties to reveal their identity. In this paper, we present a privacy-preserving routing scheme for greedy embeddings based on anonymous return addresses rather than identifying node coordinates. We prove that the presented algorithm are highly scalalbe, with regard to the complexity of both the routing and the stabilization protocols. Furthermore, we show that the return addresses provide plausible deniability for both sender and receiver. We further enhance the routing’s resilience by using multiple embeddings and propose a method for ecient