Web filtering has been a no-brainer security staple for years.
Businesses and organizations of all kinds use web filters to block online content that might be malicious, unsavory, or distracting.
For example, businesses often block social networking sites to prevent employees from wasting time. Schools are required to block pornography to protect children online. And many organizations block malicious websites that host exploits and malware.
A good web filter can fit all of these needs, but which types are good?
Choosing the right type for a client is imperative for smooth day-to-day operation, so knowing the main types of web-filtering programs is a must.
From simple to more involved, the first type of web filter on our list is browser based.
Browser-based types of web filters are typically extensions, applications or add-ons that can be installed and used with a particular web browser.
While not the most thorough filter, these types of web filters are widely available and are very convenient for users.
Another popular (and humorous) web filter available for Chrome is the Kardashian Filter, which removes all content related to the Kardashian family from user view.
The main downfall of these types of web filters is that users can circumvent them by switching web browsers. By doing so, the user renders the filter on the initial browser useless.
So if you decided to use Firefox when you’ve got the Kardashian Filter installed on Chrome, you will still be susceptible to headlines, copy and imagery that references the celebrity family.
Search engine filters
Search engine types of filters sift out unsuitable content from the results a user sees when looking up information through a search engine.
Some search engines have this feature built in to their user interface. Google and Bing have Safe Search options for those who want to filter out inappropriate content in their search results.
Both of these search engines have Safe Search on as a default, but one does not need administrative privileges to turn these filters off.
Search engine filters can also be easily circumvented if the user knows the URL of the site they are trying to access or if they use another search engine that does not have a similar filter.
Client-side filters are filtering programs installed on the device an employee or student uses.
Such filtering programs typically have to be installed and configured on each individual device, making these types of web filters more time consuming to install than others.
While these types of web filters may be ideal for a small business, larger businesses may not want to deal with the hassle of setting up this type of web filter on more than a few computers.
These types of web filters can also be easily circumvented by those who have administrative privileges since these types of web filters are often directly installed on the device and not controlled by a central program.
Content-limited ISPs are internet service providers who block off specified websites from all who subscribe to the ISP’s service.
Typically found in countries who censor content on the web, these types of web filters are gradually making their way to countries around the world.
Virgin Media for example, is an ISP that used this type of web filtering to block the Pirate Bay from subscriber access.
While these types of web filters are not yet widely available, they may be in the future.
The next type of web filtering is called network-based web filtering. Network-based types of web filters are typically implemented at either the transport or application layers of a network.
These types of web filters are set up as either a web proxy or a transport proxy to guard the network. They serve as the middleman between outgoing requests and incoming information.
They also usually guard the individual IP addresses of all of the workstations on the network by only displaying the IP address of the filter to outside users.
The Calyptix AccessEnforcer’s web filtering technology falls into this category. It uses a web proxy at the transport layer to oversee and guard the network from unsavory/unsafe content that users may try to access.
The AccessEnforcer’s web filtering capabilities can also be customized to fit a client’s needs, allowing them to block different categories of web content or specific sites.