What is content filtering?

Content Filtering

Content filtering is the screening of content to restrict or block websites. This could include material that compromises security or breaches internal content consumption policies.

Content filters manage employee access to websites, emails, or mobile communications. Almost all organizations have some form of filtering system. But filtering varies in form and scope, and many options are available.

How content filtering works

Content filters generally stand between content sources and web or device users. Users seek access to web pages, social media accounts, or emails. Information from those sources must pass through a filter before being approved.

Filters use various techniques to determine what data to allow through and what to block. Legacy systems often rely on firewall content filtering. Modern filtering services harness SaaS resources. This screens data without the need for extra hardware.

Simple content filtering systems rely on allowlists and blocklists. Allowlists include a small number of allowed sites and block access to everything else. Blocklists apply the opposite principle. They black-list a few websites while permitting access anywhere else.

Other content-based filtering systems are more flexible. Some use keyword filtering. This blocks access to pages containing banned phrases or words. Other content filters use Artificial Intelligence and machine learning to determine allowable data.

This adds a valuable layer of subtlety to content filtering. Standard filters might block phrases like “killer apps.” In other cases, filters could block harmless sites referring to erectile dysfunction. Adaptive AI-powered filters can help solve these problems.

Why is content filtering important?

Content filtering matters because organizations need ways to control behavior on their networks. Employees or contractors can act dangerously, putting assets at risk. Filtering can also play a technical role, helping IT teams optimize network performance. Here are some of the main reasons that make filtering such a pervasive phenomenon:

1. Assets need protection from malware

Content filtering protects against potentially harmful malware infections. Emails containing malicious links to fake websites are common vectors for phishing attacks. A few clicks or words typed into forms can unleash malicious software. Worms, ransomware agents, or trojans all represent a critical data loss risk.

Website filtering is an important component of DNS layer security, minimizing the risks posed by malicious actors. Filters scan websites for potential threats, matching watchlists with website content. They block dangerous sites or suspect links automatically. This reduces the risk of successful phishing expeditions.

DNS filtering also protects against exploit kits, also commonly delivered via fake websites. Exploit kits hijack browsers or extensions. They can extract sensitive data, spy on traffic, and take down internet infrastructure.

2. Filtering contributes to heightened productivity

Companies use content-based filtering to create productive environments free from distractions. Simple filtering mechanisms block social media networks or streaming sites. Both types of websites divert employees from core tasks. Managers can also apply content filters dynamically. That way, they only function during work hours. This provides more flexibility for remote workers.

3. Filtering improves network performance

Content filtering is a reliable way of avoiding traffic spikes. Non-essential sites like YouTube consume large amounts of bandwidth. That’s especially true when large communities of users stream simultaneously. Banning access to high-bandwidth sites is a sensible option to conserve network resources. 

4. Regulatory compliance requires filtering systems

Some business sectors use content filtering systems to meet regulatory requirements. Organizations working with young people may need filters to comply with the Children’s Internet Protection Act (CIPA). CIPA demands that networks block websites featuring obscene, pornographic, or violent content. There are significant penalties for non-compliance. The potential for reputational damage is also high. 

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Benefits & use-cases of content filtering

Companies use content filters in many ways across different forms of technology. There are many practical applications, and almost every business sector uses some form of filtering. Use cases include:

1. Regulating internet access in educational institutions

Education is a $1.7 billion industry in the USA. As of Fall 2021, almost 50 million students were enrolled up to Grade 12. Almost all students use the internet. They all need protection from harmful or unwanted content, and web content filtering is the best solution.

Schools use safe search filters supporting many languages that work with all student devices. They also need adaptive filters. Filters must block pornographic content without compromising essential education services like Google Classroom.

2. Making office workers more productive

In 2017, analysts Bridge by Instructure surveyed 1,000 American workers. They found that workers watched an average of 77 minutes of non-work video content daily. Around 80% of employees use social media at work. That adds up to a lot of wasted hours and lost productivity.

Web content filtering allows companies to block widely used social media or streaming sites. This allows employees to focus on work tasks. Some filters can also block chat functions while retaining access to social feeds. And roles that rely on social media access can receive the permissions they need.

3. Maximizing bandwidth

Web content filtering often blocks non-essential sites that consume large amounts of traffic. Bandwidth analysis allows network teams to identify the major culprits. They can then place offending sites on blocklists. Everything else remains permitted, but scarce bandwidth will not flow to unproductive locations.

4. Reducing data loss risks via endpoint protection

Data breaches are a significant cybersecurity risk, with average costs reaching $4.35 million per incident in the USA. Companies can use web content filtering to strengthen their endpoint defenses. Filters block high-risk websites or links, making life much harder for data thieves.

Email filtering removes harmful messages. This removes the risk of employees clicking phishing links. Website filtering adds an extra line of defense, applying regularly updated global blocklists. Specialist mobile SMS filtering is also useful in many remote work situations.

What are the main types of content filtering?

Content filtering covers a variety of different technologies and capabilities. Most companies use a mixture of the following filtering styles:

1. Internet and web filtering

Internet and web filters restrict website access according to blocklists or real-time AI analysis. Security teams can apply filters to individual pages. At the same time, they can preserve access to general website content. Web content filtering can also block social media portals such as Facebook. And it can filter undesirable content like torrenting portals.

Companies can manage internet filters via hardware or software firewalls. They can also add content filters to web browsers as extensions. In reality, both options tend to work together to screen harmful online content.

2. Email filters

This style of content filter only screens content passing through corporate email servers or clients. IT teams assign a set of filtering protocols for every user. These protocols determine which messages to categorize as spam and which remain in email inboxes.

Email filters generally check headers and body text for anomalies and keywords. They should also be able to scan attachments for malware. Mail filters often refer to global lists of known spam sites and phishers. These lists tell them to block content from flagged addresses instantly.

3. Search engine filters

Search engine filters apply controls to the output of search engines such as Google. Users can exclude adult content, search by location, exclude older search terms, and remove keywords from results if necessary.

Some search filters can block specific URLs. They may also work alongside enterprise search tools that index and search internal assets.

4. Content filtering proxy

Proxies sit between user devices and content sources such as the World Wide Web. They apply filters to data that passes through. This creates a robust endpoint to screen inappropriate or malicious content.

This form of content filter is often used in educational contexts. That’s because proxies offer a dependable solution for groups of networked computers.

5. Mobile filters

Less common content filter types control the content delivered to mobile devices. Mobile Device Management (MDM) tools install filtering software on smartphones or tablets. MDM filtering software applies the company’s security protocol, filtering data as required. Software may include standard web filtering alongside tools to screen SMS messages.

DPI (Deep Packet Inspection)

Deep Packet Inspection is another form of establishing which resources are available to network users. DPI operates via virtual gateways such as VPNs. It inspects the data content of packets as they pass across network boundaries. If filters detect any prohibited code or text, they can deny access.

DPI consoles allow network teams to decide which protocols are allowed. This can exclude data from popular streaming services, gaming websites, messaging apps, or social media platforms. Managers can change exclusions and set user-specific permissions with a few clicks. It’s a flexible option that can be embedded in network security software.

Choosing between hardware, software, and cloud-based content filtering

We can also define filters as hardware, software, or cloud-based. These network content filtering solutions have different features. Knowing how they differ when constructing a security filtering solution is vital. 

  • Hardware filtering – These filters are installed on content filtering devices. These devices integrate with existing network infrastructure. They may also operate as proxies between on-premises networks and the wider internet. 

  • Software filtering – In this case, content filtering software functions on corporate devices. This includes office workstations, remote working laptops, and mobile devices that send or receive work emails.

  • Cloud filtering – Filtering tools are contained within the cloud and provided via a SaaS model. There is no need to source new software or hardware to implement cloud filtering solutions.

Which option should companies choose? Cloud filtering is relatively new but offers significant advantages over legacy filtering methods:

  • SaaS content filtering requires no wholesale changes to existing infrastructure.

  • Centralized data centers are not required, reducing the need for investment.

  • SaaS filters can scale rapidly if organizations modify their networks or their bandwidth requirements grow.

  • There is no need to manage updates on distributed devices. Everything is provided via a single SaaS system, which works on any device.

In some cases, a firewall content filtering service can build on existing infrastructure effectively. But next-generation cloud options suit SaaS users and could be the best option available.

Find the right content filtering solution with NordLayer

Content filtering is an essential capability for most modern businesses. Companies must screen inappropriate or illegal content. They need to ensure employees focus on core tasks. They must also guard against malware and phishers. Sophisticated filters carry out all these tasks. They automatically deliver approved content exactly where workers need it.

NordLayer offers comprehensive cloud-based filtering solutions for organizations of any type or size. Take advantage of filters optimized for desktops, laptops, iOS, and Android devices. Screen web traffic with advanced DNS filtering to allow access to the sites that matter. And track all network traffic via Deep Packet Inspection. Get in touch today to find out more.

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