Vivisecting Blockchain P2P Networks: Unveiling the Bitcoin IP Network

Blockchains are typically managed by peer-to-peer (P2P) networks, which provide the support and substrate to the so-called distributed ledger (DLT), a replicated, shared, and synchronized data structure, geographically spread
across multiple nodes. The Bitcoin (BTC) blockchain is by far the most well-known DLT, used to record transactions among peers, based on the BTC digital currency. In this paper we focus on the network side of blockchain P2P
networks, characterizing their topology and main properties from a purely network measurements-based approach. We present a BTC crawler able to discover and track all the active nodes of the BTC P2P network through active
measurements, and use it to analyze its main properties. We additionally discuss a passive measurements-based approach to reconstruct the topology of a blockchain P2P network, which can unveil the most important nodes of the
blockchain, namely the miners.