In peer-to-peer (P2P) networking, a group of computers are linked together with equal permissions and responsibilities for processing data. Unlike traditional client-server networking, no devices in a peer-to-peer network are designated solely to serve or to receive data. Each connected machine has the same rights as its “peers”, and can be used for the same purposes.
P2P networking comes with a number of benefits. As an example, in a traditional client-server network model, if a server goes down, it can take the whole network with it. But in P2P, if a single device goes down, the others on the network can help pick up the slack. They also help ensure network traffic doesn’t get bottlenecked at one device, since traffic handling is distributed across many computers.
If you’re aware of P2P networking, you’ve probably heard about it in the sense of file sharing. For instance, P2P software like Kazaa and Napster was once a standard find on the average home user’s computer. These programs allowed users to swap large files over the internet, typically music and movies. Rather than using central servers for this purpose, they used their worldwide user base’s computers as both client and server (ie. P2P), effectively offloading processing loads onto their users. Although these programs are no longer in play, P2P file sharing is alive and well (think BitTorrent and the like). Even instant message (IM) clients can serve this function, since the majority of them support sharing files in addition to chatting.
While there are numerous legitimate uses for P2P networking, the file sharing aspect raises both intellectual property and cybersecurity concerns. Any time people are sharing music, movies, software, or any other proprietary content, questions of intellectual property and copyright laws surface. In fact, some internet service providers have attempted to ban torrents and other P2P applications, despite the valid and perfectly legal functions P2P can serve. Additionally, P2P file sharing can be used to distribute malware, share or publicize confidential data, and gather users’ personally identifiable information. They are also highly vulnerable to denial of service attacks, since each device helps route traffic through the network.