File sharing is the activity of making files available to other users for download over the Internet, but also over smaller networks. Usually file sharing follows the peer-to-peer (P2P) model, where the files are stored on and served by personal computers of the users. Most people who engage in file sharing are also downloading files that other users share. Sometimes these two activities are linked together. File sharing is distinct from file trading in that downloading files from a P2P network does not require uploading, although some networks provide incentives for uploading such as credits or force sharing of files being currently downloaded.
Napster, originally a centralized service, was the first major file-sharing tool and popularized file sharing for the masses. Napster was an MP3-only sharing system and was successfully shut down by legal attacks from the music industry. It was openly attacked by some artists (notably Dr. Dre, Metallica) and supported by others (Limp Bizkit, Courtney Love, Dave Mathews). There was widespread media coverage of unreleased Madonna songs leaking out on to the web prior to the official commercial release. Napster was a localized index for MP3 files shared by the users logged into the system. It included IRC-like chat and instant messenger features. Almost all new, major clients now follow its example in design.
Even before its legal problems, the community created an alternative: OpenNap. A reverse-engineered version of the Napster protocol, it was released as the open source server alternative for Napster users. These networks continue to exist even after Napster's collapse and many clients using this protocol have appeared, particularly with the help of the Napigator server list - an effort to centralize all of the different servers and networks.
Afterwards, Gnutella, a decentralized network, appeared. This service was fully open-source and allowed users to search for almost any file type; users could find more than just MP3s on these networks. It was created/supported in response to threats towards centralized bodies like Napster. The thought behind decentralization is that no one broken link can bring about the downfall of all members. But Gnutella has experienced growing pains since its use skyrocketed.
Napster and Gnutella continue to define file sharing today, forming the extreme at both ends of the law in the wake of a series of civil lawsuits filed against computer users by the RIAA (which began in September, 2003). Gnutella, a free and open protocol and service, with its lawless structure but poor scalability, while Napster having been resurrected as a legal online music service that competes with other such legal services as iTunes and Rhapsody.
Most file-sharing systems since have sought to ride the line between these two extremes.
Today a variety of file-sharing programs is available on several different networks. Availability depends partly on operating system, and different networks have different features (for example, multiple-source downloads, different sorts of search limiting, and so on). It is common for commercial file sharing clients to contain abrasive advertising software, or spyware.
There are several major topics surrounding file sharing. Of them, the two primary dynamics are the benefits and drawbacks of centralization vs decentralization and privacy / anonymity, especially vs copyright protection and file-sharing legality. As well as the problem of spyware, a method for the companies that produce peer-to-peer programs to make money on their product. It is these pulls which have defined several themes of software.
In the early days, client software was protocol-specific, so you had "Napster" clients, and you had "Gnutella" clients. There is an everpresent push towards making the GUI-side of things capable of using multiple protocols. After all, why should a user have to load up several different applications to do what is, in their mind, the same thing?
In cases where there is perceived value in collecting, some people will have lots to share and will find themselves surrounded by eager people. This can cause problems when the collector cannot keep up with demand. Decentralization is one means to alleviate this problem, especially in cases where it is possible to ensure that multiple copies of a popular item are available from multiple sources (even simultaneously, as with multi-source downloading).
Decentralization has also been widely pushed over the fear of having a centralized network attacked, either by legal disputes or hostile users. One argues that a decentralized network has no body to attack, only individual ethereal members. While the foundation protocol of the Internet TCP/IP was designed to be robust and withstand concerted attack, file-sharing and peer-to-peer systems are proving even stronger.
Concepts like leeching or hoarding come about where the one centralized person will collect and will not later freely give away what was given. Trade and ratio systems evolve in order to reduce the impact of leeching. Under these systems, a person will only share when they can expect to get something in return. Kazaa has a very simple rating system. Your Client calculates your priority and tells the sources what priority they should give you. Very soon there have been hacks that your client tells the sources that you have a high priority. Another client which has a rating System is emule. Your client stores how much you have down and uploaded from one source, if you receive a file or let other peers download files from you. It seems that this rating system does not have a big impact on the download speed. A reason could be the size of the upload queue and the Chunk size. If there is a free upload slot, your client takes the peer on top, transferes 8MB to it and puts it in the Queue on the end. A peer with rating x2 would have to wait half the time than the first peer to get an upload Slot. But if the first had been in the queue since four hours or so, than the x2 Client would have to wait for two hours. This System has a very big reaction time. After your Client has received a 8MB Chunk, it should upload an 8MB Chunk to the other peer as soon as possible. Then the other client would upload one chunk to you and your download speed and the one from the other client will increase. Bittorrent also has a very good rating system. The download speed is very slow, if you don't upload anything. The future will probably be something between the emule and the overnet system: Your client and another peer decides to transfer one chunk to each other the same time and then terminate the connection.
So today we are left with a slew of clients with functionality designed around making sharing files more effective, both in the real sense of uploading and downloading (like anti-leeching functions) and in the more ethereal sense of being bulletproof towards legal issues (as with anonymity and decentralization).
Anonymous, Internet file sharing (such as Gnutella and Napster) grew in popularity with the proliferation of high speed Internet connections and the (relatively) small and high quality MP3 audio format. Although file sharing is a legal technology with legal uses, some people (in practice, the great majority of users) have used it to download copyrighted materials. This has led to counter-attacks against file sharing in general from some copyright owners.
There has been a great discussion over perceived and actual legal issues surrounding file sharing. In circumstances where trading partners are in different countries with different legal codes, there are significant problems to contend with. What if a person in Canada wishes to share a piece of source code which, if compiled, has encryption capabilities? In some countries, a citizen may not request or receive such information without special permission.
Throughout the early 2000s, the entire file-sharing community has been in a state of flux, since record companies and RIAA tried to shut down as much of this as possible. Even though they have forced Napster into cooperating against copyright violations, they are way behind, since the community has flourished and produced lots of different clients, though not as many different underlying protocols. The second generation of P2P protocols, such as Freenet are not as dependent as Napster is on a central server, making it much harder to shut down these systems through court actions. Another attempt (used by the maintainers of KaZaA) is to change the company's organization so that it is impossible or useless to attack it legally.
The EFF is a donor-supported group which protects the digital rights of mankind. The EFF is involved in legislation, court cases and campains to make the public aware of their rights. The EFF has opposed the RIAA in its onslaught of law suits against users of file-sharing applications. The foundation supports the idea that P2P file-sharing can exist while allowing users to compensate artists for their copyrighted material.
Communities and external links
- Findhash.com - A Web Site indexing media content for many different filesharing client using quicklinks (AKA hashlinks)
- Hack the Planet - Wes Felter comments frequently on P2P-related issues in his weblog.
- InfoAnarchy - File Sharing / Anonymity Tools - Reviews and forums.
- OpenP2P - O'Reilly's Peer-to-Peer portal with news and papers. Interesting for developers and businesses.
- Peer to Peer guide for the Mac with overview of p2p-clients for Mac OS X.
- Planet Peer - Planet Peer is a comprehensive portal for mainly anonymous file-sharing programs like MUTE, Freenet and Entropy. We are hosting the official MUTE Wiki also and have a forum which deals with everything concerning issues with anonymous file-sharing tools
- Slyck - Covering file-sharing and copyright issues along with new and established clients by popularity, size, platform, and more.
- Sharelive.com - A Web Site that helps download confirmed, public files from multiple networks.
- ShareReactor - Was a Web Site that helped download confirmed, public files from the Multisource File Transfer Protocol used by such programs as Edonkey2000 and eMule. It was taken down by Swiss Police on March 10th, 2004 due to the suspicion of breach of copyright and trademark laws.
- Zeropaid.com - The File Sharing Portal - Programs, News, Forums
Papers, articles, and infant projects
- The Napster Experience - Critical consumer research (Markus Giesler, York Universisty) analyzing file-sharing as a form of gift giving and consumer emancipation.
- A Method of Free Speech on the Internet: Random Pads (by David A. Madore) - Discusses how information can be completely separated from its creators by XORing it with chunks of random data. The resulting "pads" can then be distributed across so-called "pad archives". A pad archive neither knows what it is hosting nor does it host provably controversial data, since the data cannot be distinguished from noise. It's mainly a legal question: If the courts would outlaw hosting random data, it wouldn't work. Other than that, it's pretty safe -- interesting read, and there are already quite a lot of pad archives (thanks to Slashdot).
- SafeX - Secure and Anonymous File EXchange. Just a draft with many interesting ideas to use in other projects.
- The Free Haven Project - Similar goals to Freenet, with different solutions. Some interesting papers. Not much code yet.
- The Big Hack: Home of the OFF System - A crusade originaly started to create a peer-to-peer system of file exchange where everything exchanged is legal. Originally designed, created, and coded by a blind community activist naming himself WhiteRaven, he has since left that site due to the fact that it was in fact a part of a interactive media companies sick joke. After being abused by the company in question he left taking part of his notes and code with him, but not before the company stole his source forge account and took over the project in the hopes of using it to band the p2p community together in order to sell them site merchandise. WhiteRaven went on to help with the creation of Monolith ( http://monolith.sourceforge.net/ ).
- OceanStore - OceanStore is "designed to span the globe and provide continuous access to persistent information". "Data is protected through redundancy and cryptographic techniques. To improve performance, data are allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development."
- Fling | Sourceforge page - An attempt to provide anonymity on the protocol level (i.e. replace TCP/IP). Still in the planning stages as of Nov 2002.
- Ben Houston's P2P Idea Page - Ben Houston has written a lot of interesting analyses of distributed systems, among them proposals for more efficient, self-organizing and self-optimizing networks.
- The Eternity Service by Ross Anderson - This paper is a rather simple suggestion for a redundant, anonymous storage system with payment features.
- Intermemory Project - Aims to create "large-scale, self-organized, survivable, available, and secure widely-distributed storage". See papers.
- Who's on First Proposal - This page introduces the Who's On First (WOF) anonymous network, which is the working title of a proposal for a more flexible and reliable anonymous communication network than that provided by current Type I and II remailers.
- JetFile - Proposal for a scalable distributed file system (some parts are centralized).
- Legal Downloads
- Good News For File Sharing? - shumans.com, August 2004
- The Darknet and the Future of Content Distribution (Microsoft Word format)
This article was partly based on public domain material from the infoAnarchy wiki.
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