Dandelion: Redesigning the Bitcoin Network for Anonymity
  Bitcoin and other cryptocurrencies have surged in popularity over the last
decade. Although Bitcoin does not claim to provide anonymity for its users, it
enjoys a public perception of being a `privacy-preserving' financial system. In
reality, cryptocurrencies publish users' entire transaction histories in
plaintext, albeit under a pseudonym; this is required for transaction
validation. Therefore, if a user's pseudonym can be linked to their human
identity, the privacy fallout can be significant. Recently, researchers have
demonstrated deanonymization attacks that exploit weaknesses in the Bitcoin
network's peer-to-peer (P2P) networking protocols. In particular, the P2P
network currently forwards content in a structured way that allows observers to
deanonymize users. In this work, we redesign the P2P network from first
principles with the goal of providing strong, provable anonymity guarantees. We
propose a simple networking policy called Dandelion, which achieves
nearly-optimal anonymity guarantees at minimal cost to the network's utility.
We also provide a practical implementation of Dandelion.
