Content filtering is the use of a program to screen and/or exclude access to web pages or email deemed objectionable. Content filtering is used by corporations as part of their firewalls, and also by home computer owners. Content filtering works by specifying content patterns – such as text strings or objects within images – that, if matched, indicate undesirable content that is to be screened out. A content filter will then block access to this content.
Content filters are often part of Internet firewalls, but can be implemented as either hardware or software. In such usage, content filtering is serving a security purpose – but content filtering is also used to implement company policies related to information system usage. For example, it's common to filter social-networking sites unrelated to work.
Objectionable, inappropriate, or illegal content creates risk for organizations. For example:
- Allowing pornographic content into the workplace can put a company at risk for sexual harassment claims, or otherwise create a hostile or demeaning work environment.
- Spam sites can lead to malware or other malicious software being installed onto work computers.
- Hate sites or sites with violent content can compromise employee safety and also reflect poorly on the company as a whole.
- Social networking sites can reduce productivity and distract employees from routine tasks.
Content filtering helps to mitigate these risks by making such content difficult to access in the workplace, and by demonstrating the company’s intolerance for inappropriate, illegal, or objectionable content in general.
To be effective, content filtering has to be deployed across all content channels. The most common channels include:
- Web: The screening of Web sites or pages, as well bookmarks and other web traffic.
- Email: Screening of email for a variety of spam, malware and other undesired or malicious content. This is usually done by scanning the subject line of the emails forwarded through the filtering system. When a message is received that fills the relevant criteria, the message will be placed in the recipient’s junk folder. In some cases, it will even be sent back to the sender as undeliverable.
- Executables: The screening of executable files that may install malicious software without warning.
The motive is often to stop access to content that the user or administrator might determine is objectionable. Some of the restrictions can be applied at all levels: a national government can attempt to apply them nationwide, or an ISP can apply the filtering to its clients, even an employer to its personnel or a school to the student-body. There are no limitations to the scope of email filtering, and it can often be a strong step towards providing security to any and all users accessing the web.
How Barracuda Can Help
The Barracuda Web Security Gateway provides flexible controls for pinpoint content filtering of online activity. With it, administrators can easily block dangerous online behavior such as viewing pornography, violence, or even engaging in hacking.
Do you have more questions about Content Filtering? Contact us today.