Blockchain 101

Decentralized Systems

Peer-to-peer networks, often shortened as P2P, are an essential component to blockchain systems and enable the decentralization that is key to the system architecture.

Rather than a typical client-server model in which individual clients request services or information from a central server, a peer-to-peer network is more resilient and allows peers on the network to directly interact with other peers. Peer-to-peer networks are self-organizing and therefore can be self-sustaining. This is a significant component of decentralized systems that allow blockchains to do what they are purposed for.

P2P networks help to ensure resiliency in the network. As more nodes arrive in the system, and the demand on the system increases, the total capacity of the network increases.

As this happens, the likelihood of failure in the system decreases because of the growth in peers on the network; these nodes support the system through their contributions to the network and by sharing resources. Because the system’s capacity can increase in these situations, and more peers mean more resources on the network, it allows for greater resiliency overall. If one peer on the network fails, the system still survives because all the other peers are still properly functioning and providing resources to the network. The redundancy in information between nodes makes sure that if one node goes offline, there is another available node with a copy of that information. Peer-to-peer networks significantly decrease the chance of a network failure simply by the nature of the system being decentralized throughout nodes. This creates a network with great fault-tolerance meaning that the network is able to continue functioning even when a node does not behave properly.

Decentralization is key to a blockchain networks security model. See 51% attack.