Web Filter

Before Web Filter

During the early days of internet, there was little to no restrictions on what websites you could visit. Unfortunately, some of those websites had malware that could infect the browsing computer. Or, sometimes the website had content others objected to. While controversial, most countries do filter their web based on their opinion and beliefs. Security against malicious websites, and other content such as beliefs, gave birth to web filtering.

Web Filtering Definition

It's an application that scans incoming webpages to determine if some or all content should be blocked. Web filtering makes those decisions based on rules set by the organization, or individual who install the application. There is a corresponding interface that allows you to configure the rules, and determines what's allowed to get through and what gets blocked.

Web Filtering First Implementation

In the United States, public libraries were forced to install a web filter due to public pressure. The federal government passed the Children Internet Protection Act (CIPA) in 2004 requiring all public accessible computers to have a web filter, if that library accepted federal funds from the government. These measures were met with mixed opinions. As Web filtering spread from libraries to schools, some argued that censoring information, no matter how offensive it is, countered the mission of education. Moreover, sometimes the web filter could not distinguish between art and lewd art, same with expletive content in some books. These, complaints, pushed the developers to redesign a more sophisticated web filtering software.

Web Filtering Censorship Issues

While the initial motivation was to protect children, after the technology was developed, its usage became more apparent. Information could be censored based on religious, political, idealism beliefs. Previous misdeeds of the government could be erased from the digital record. Still, on the positive side, browsing the internet became more safe. Today, web based filtering formed the first line of defense against web attacks. In addition to client workstations, web clients, and ISPs, web filters were also added to other home devices such as firewall, proxy servers, and sandbox technology, and wireless access points.

Web Filtering Architecture

Web filtering works by taking the URL you're trying to visit and comparing it to its known list of deny URLs, there is also an allow URLs. A URL enters deny list by having its domain reported "losing trust" with known web filters in popular antivirus such as Kaspersky, Cloudflare. Another method that web filtering uses is by checking the content in specific websites, or building a sentence and comparing it using AI to something they have filtered. This has caused lots of issues, especially when it comes to filtering false content, and propaganda/idealism filtering.