A peer-to-peer (P2P) network allows a disparate system of computers to connect directly with each other without the reference, instruction, or routing of a central authority. P2P networks allow for the sharing of files, computational resources, and network bandwidth among those in the network.
Peer-to-peer (P2P) networking is
|“||a generic term used to refer to several different types of technology that have one thing in common: a decentralized infrastructure whereby each participant in the network (typically called a "peer," but sometimes called a "node") acts as both a supplier and consumer of information resources. Although less secure, P2P networks are generally more reliable than client-server networks and do not suffer from the same bottleneck problems. These strengths make P2P networks ideally suited for sharing large files, a feature that has led to their adoption by, among others, those wanting access to pirated media, including music, movies, and television shows. But there also are a great number of non-infringing uses for peer-to-peer networks; copyright infringement is in no sense intrinsic to the technology, any more than making unauthorized copies of television shows was to the video tape recorder. ||”|
In a blockchain, a P2P network allows the users of the blockchain to broadcast directly to and among each other the current state of the blockchain (so that users may agree on the history of transactions), and when a new block is added. This also allows for redundancy of the data in the blockchain, as any user may download a complete copy of the current ledger of transactions and add a new block, so that there will not be a Single point of failure for the blockchain if a node on the network goes down.
In some blockchain implementations, users do not host copies of the ledger among themselves. Instead, users use a cloud service provider (CSP) to maintain active and back-up copies of the blockchain, and compute the transactions and blocks as they happen. In these cases, peer-to-peer networking is necessary to run the blockchain. While the CSP is not a central validating authority in this example, it does become a third party to the transaction.
- See generally [[MGM v. Grokster|Metro–Goldwyn–Mayer Studios, Inc. v. Grokster, Ltd. ("Grokster III"), 545 U.S. 913, 920 & n.1, 125 S.Ct. 2764, 162 L.Ed.2d 781 (2005).
- Compare A&M Records v. Napster, Inc., 239 F.3d 1004, 1021 (9th Cir. 2001) with Sony Corp. of America v. Universal City Studios, Inc., 464 U.S. 417 (1984).
- Columbia Pictures Industries, Inc. v. Fung, 710 F.3d 1020, 1024–25 (9th Cir. 2013).