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Anonymous web browsing refers to utilization of the World Wide Web that hides a user's personally identifiable information from websites visited. Anonymous web browsing can be achieved via proxy servers and other anonymity programs such as Tor. These programs work by sending information through a series of routers in order to hide the source and destination of information. However, there is never a guarantee of anonymity with these servers. These programs are still susceptible to traffic analysis. Proxy servers, which have a central point of knowledge, are also susceptible to collection of data by authorities. Moreover, cookies, browser plugins, and other information can be used to uniquely identify a user even if they have hidden their IP address.
When a user opens a web page, their IP address and other computer information (e.g., their device fingerprint) becomes visible to the target web page's server. This information can be used to track the user. The user's IP address can be hidden via a proxy server or a VPN server. These types of servers work by sending a request to the target server from themselves. For example, if a user requests to visit a link on a web page, the request will-- instead of being sent directly to the web site server-- be sent to the proxy server, which then relays the request to the targeted internet server. This hides the user's IP address from the target server, as only the proxy server's information is visible. On the other hand, device finger prints are relatively resistant to anonymization. While some data can be hidden or spoofed, this can actually make a particular user more unique and thereby less anonymous. NoScript and Tor, however, appear to be very effective for creating anonymity.
Anonymous Web Servers generally work by placing an anonymous proxy between a user and the website they are visiting. These servers can be used to bypass restrictions and visit sites that might be blocked in a specific country, office, or school. Some individuals use these servers solely to protect their personal online identity.
Anonymous web browsing is generally useful to Internet users who want to ensure that their sessions cannot be monitored. For instance, it is used to circumvent traffic monitoring by organizations who want to discover or control which websites employees visit.
It has been posited that Internet anonymity is impossible as law enforcement officials can request logs from the user's Internet provider if the officials suspect illegal activity. In practice, however, these are not major concerns because Internet providers that emphasize personal data protection will typically only save their log files for a few days at which time they are deleted/overwritten by rotation. Backups are rotated in a similar fashion. To further obscure the client IP addresses that are stored in the log files, they can be truncated by the last byte and thereby made (more) anonymous.
Proxy servers have a number of limitations. Primarily, web pages will sometimes load at a slow pace as user information must be rerouted. Further, the server is attempting to bypass suspicious software, some elements of a page may not load. Since personal information, such as credit card numbers and passwords, has been passed through an external server that could be accessed by anyone, proxy servers are more of a security hazard than browsing the web without a proxy (if not on an encrypted channel (HTTPS)).
HTTP cookies are strings of text that are saved on a computer when a user browses different web pages. Cookies allow small bits of information to be stored, such as passwords and shopping lists. They are also used to track demographics and browsing habits. This information is sent to the user's computer and then uploaded to web databases without the user's approval. Cookies represent another avenue (besides transmission of the IP address) by which a user's anonymity can potentially be breached.