Dandelion(++): private transaction routing

Bitcoin is pseudonymous, offering users the ability to interact with the network without exposing their real identity.

The Bitcoin gossip protocol exposes participants’ IP addresses, however, which can potentially be used to deanonymize users. Before transactions are included in a block, they are broadcast to the network, and an attacker can run a spy node that tracks the times at which it receives these transactions to link a user’s IP address to their Bitcoin address and use this information to all deanonymize their payments on the network. Bitcoin’s transaction propagation technique makes it relatively simple to perform such an attack.