Anonymous messaging platforms, such Secret, Whisper and Yik Yak, have emerged as important social media for sharing one's thoughts without the fear of being judged by friends, family, or the public. Further, such anonymous platforms are crucial in nations with authoritarian governments, where the right to free expression and sometimes the personal safety of the message author depends on anonymity. Current platforms offer only superficial anonymity – their centralized implementation makes them naturally vulnerable to authoritarian adversaries and/or economic incentives.
In this talk, we study the problem of designing a distributed messaging protocol that spreads the message fast while keeping the identity of the source hidden from an adversary. We present an anonymous messaging protocol, which we call adaptive diffusion, and show that it spreads fast and achieves nearly perfect obfuscation of the source for a wide range of adversaries. System issues in the implementation of the protocol are discussed.