A peer-to-peer network is a distributed system in which devices communicate directly with each other instead of relying on a central server. Each node can act as both a client and a server, sharing data, messages, or files across the network.
In cyber security, peer-to-peer design matters because it removes a single point of failure. Attackers can use P2P channels for command-and-control, making infrastructure harder to block, take down, or sinkhole with simple domain or IP filtering. Malware may also use P2P routing to spread updates or relay commands through multiple peers. Defenders look for unusual encrypted traffic patterns, direct connections between endpoints, and behavior that does not match normal business applications. P2P is not inherently malicious, but in an attack it often signals resilient, decentralized control that can outlast basic blocking measures.