Mastering Bitcoin, 3rd Edition

Chapter 10. The Bitcoin Network

Bitcoin is structured as a peer-to-peer network architecture on top of the internet. The term peer-to-peer, or P2P, means that the full nodes that participate in the network are peers to each other, that they can all perform the same functions, and that there are no “special” nodes. The network nodes interconnect in a mesh network with a “flat” topology. There is no server, no centralized service, and no hierarchy within the network. Nodes in a P2P network both provide and consume services at the same time. P2P networks are inherently resilient, decentralized, and open. A preeminent example of a P2P network architecture was the early internet itself, where nodes on the IP network were equal. Today’s internet architecture is more hierarchical, but the Internet Protocol still retains its flat-topology essence. Beyond Bitcoin and the internet, the largest and most successful application of P2P technologies is file sharing, with Napster as the pioneer and BitTorrent as the most recent evolution of the architecture.

Bitcoin’s P2P network architecture is much more than a topology choice. Bitcoin is a P2P digital cash system by design, and the network architecture is both a reflection and a foundation of that core characteristic. Decentralization of control is a core design principle that can only be achieved and maintained by a flat and decentralized P2P consensus network.

The term “Bitcoin network” refers to the collection of nodes running the Bitcoin ...