Membership-Concealing Overlay Networks

The authors introduce the concept of Membership-Concealing Overlay Networks (MCONs), which hide the real-world identities of participants. They argue that while membership concealment is orthogonal to anonymity and censorship resistance, pseudonymous communication and censorship resistance become much easier if done over a membership-concealing network. They formalize the concept of membership concealment, discuss a number of attacks against existing systems and present real-world attack results. The authors then propose three proof-of-concept MCON designs that resist those attacks: one that is more efficient, another that is more robust to membership churn, and a third that balances efficiency and robustness.