Trilight Zone

[digital8]

Every device on the Internet (including online computers) has an IP address, an identifying number used to route data. This number is assigned by the device's Internet Service Provider (ISP), and may be semi-permanent (for example, assigned for the duration of an account) or temporary (many dial-up connections, for example, are given new IP addresses each time they connect).

Every packet (piece of data) moving through the Internet is tagged with the IP addresses of who its source and destination. This is essential for the proper working of the Internet. Consequently, any direct connection between two devices on the Internet (such as when a personal computer reads a website) reveals both IP addresses to both parties.

An IP address is sometimes personally-identifiable data, and may therefore be subject to privacy concerns. An IP address identifies its user's ISP, and often identifies its user's (or the ISP's) nation, region/province/state, and sometimes even city. The amount of information that may be found from an IP address is determined by the ISP's policies. See also: DNS, whois.

Any web site can track the movements of users through its pages by their IP addresses. This can be used for profiling within a single site.

An IP address is the minimum amount of information needed to attack a computer over the Internet.

People seeking Internet anonymity are usually interested in hiding their IP address from third parties. The only way to do this (without loss of Internet use) is to connect through one or more anonymous proxies. An anonymous proxy is a special Internet server that connects to remote hosts (a web site, for example) on behalf of the user. The remote host communicates with the proxy, and receives the proxy's IP address rather than the real user's. The proxy, however, knows the IP address of the user, and sees all data passing between the user and the website; therefore the anonymous proxy has the opportunity for abuse of the user's privacy, whether intentional or accidental. Onion routing is one method intended to address this problem; it is used in such systems as Tor, I2P and Freenet.