There was a time when Napster and Gnutella were used for file sharing but then came Kazaa. Formerly capitalized as KaZaA. The plus point for Kazaa is that it not only allows its user to share simple files but also videos, television shows, and many other types of digital information. And because of its worthy features, it soon became popular among millions of people as one of the largest file sharing site. But it had to face the same problem as Napster had to face, because many film industries started criticizing it because of its unlimited video sharing feature.

Main idea

Kazaa is a decentralized Internet peer-to-peer file-sharing program owned by Sharman Networks, developed in March 2001 by programmers Niklas Zennström and Janus Friis of the Dutch company Consumer Empowerment. It is a file sharing program, which allows you to download audio, video, images, documents and software files. Kazaa has had problems with people contacting viruses from their software but Kazaa are trying to sort the problem out. Unlike the file-sharing program Napster, this used a centralized server to index files, Kaaza users share files directly from each other’s hard drives. A computer’s owner can decide during Kazaa setup which files on their computer will be available for sharing.

Working Criteria

When a user wants to find files, the user’s ON sends a query with keywords over the TCP connection to its SN. For each match in its database, the SN returns the IP address and metadata corresponding to the match. Each SN also maintains long-lived TCP connections with other SNs, creating an overlay network among the SNs. When a SN receives a query, it may forward the query to one or more of the SNs to which it is connected. A given query will in general visit a small subset of the SNs, and hence will obtain the metadata information of a small subset of all the ONs.The peer-to-peer searches occur through users with fast connections, called Supernodes. Once located, the file is sourced for downloading directly from the user who has it. When a user installs the Kazaa software on his or her computer, it comes coded with a list of supernodes. Every time the user launches the Kazaa application, his or her computer registers with the central server and then chooses from a list of currently active supernodes. When the computer sends out a request for files the user wants to download or upload, the request is funneled through the supernode. The supernode communicates with other supernodes, which in turn connect to regular nodes that in turn connect to even more regular nodes, to fulfill the request until the Time to Live of 7 runs out — this means that the search request will extend seven levels into the network before it stops propagating.


Kazaa is actually a legal program but because of the way it’s used, its developing company and several users have already been sued for copyright violation. Uploading or downloading works protected by copyright without the authority of the copyright owner is an infringement of the copyright owner’s exclusive rights of reproduction and/or distribution. Due to it being used primarily for this purpose, the creators of Kazaa have been sued for being a sort of “enabler” for piracy. Since 2008 there has been a new owner of Kazaa who made unlimited, unrestricted, and safe downloads at a monthly phone bill fee. But Kazaa has a lot of spyware in it which makes it use a bit unsafe.