What is a Secure Web Gateway?


A secure web gateway is a web security service provided on-premises or through the cloud for the purpose of verifying and filtering unauthorized traffic from accessing a network. These gateways have revolutionized the way we implement unified security across remote sites and across the web, regardless of the number of users involved. In addition to providing security, secure web gateways help users protect against data breaches and ensure compliance with increasingly stringent regulations in this area. All of this warrants a closer look under the hood of these essential security tools and a contrasting comparison with seemingly similar solutions in the security market.

What is the mission of a secure web gateway?

Secure Web Gateways (SWGs) use the architecture that allows them to accomplish their primary task: keeping your network clean by filtering out unwanted segments of Internet traffic and keeping dangerous websites at bay. These gateways put data at the center of their attention, helping them focus on threats before they even enter your virtual perimeter.

Speaking of data, SWG sees it as a primary infection vector that lurks behind the scenes of malware as a vector. To filter out malicious data, secure gateways will combine security barriers such as URL and network filtering and malware elimination, malicious code detection, application controls and anti-data leak features . These layers of security can help you protect sensitive data from theft, including but not limited to social security numbers, medical records, credit card information, and more.

In large organizations, secure web gateways play an additional role of moderating content for groups of users. As business assets must be carefully balanced between accessibility and security, secure web gateways bring order to the chaos of people, sites, applications, sensitive data, and work processes that must be protected. All of these must also be made accessible to internal and authorized stakeholders, with threat actors intercepted, vetted, and either let in or quarantined.

How does a secure web gateway work?

Secure web gateways function as web proxies that can both stop web traffic and proxy it. All traffic is inspected in order as part of security checks and in accordance with applicable security policies. The techniques featured in the secure gateway package may include anti-malware checks, web filtering, sandboxing, web isolation, data theft measures, and more. Sometimes these go hand in hand with machine learning processes and cloud access security broker (CASB) controls.

All of these checks are performed in accordance with the security policies that guide the operation of a secure web gateway. Once defined, these will determine how a secure web gateway implements threat prevention, how security policies are enforced for an individual or group, how a particular type of content is managed (accessible or prevented from loading) and other considerations. These policies must be implemented in a flexible and scalable way to meet the needs of increasingly sophisticated threats. This also includes frequent updates and preparation to combat zero-day threats.

The Role of URL Filtering

URL Filtering describes the technology used to sift through all incoming network traffic and compare it to information in databases to limit access to dangerous sites such as those containing malware or phishing code. . Typically, these databases contain information about what is allowed or prohibited, such as social media platforms, gambling and adult sites, online stores, etc.

URL filtering (opens in a new tab) engine often acts as the first line of defense in a secure web gateway. It prevents access to unwanted URLs and acts as a barrier against evolving threats. The latter is done by identifying and learning from dangerous URLs that match what is in the database of malicious sites.

Sandboxing comes next in the defensive perimeter line – it is a cybersecurity technique in which potentially dangerous code is placed in an isolated environment to be observed and analyzed. This is done by emulating standard web environments that can be found among regular users. Building on this, sandboxing can provide you with a real-time shield that prevents code-based attacks on valuable assets.

Browser/web isolation is yet another layer of security in a secure web gateway. This is to contain browsing activity in an isolated computing or server environment, such as a virtual machine. In this way, users are protected against malicious server code, data theft and malware in general.

Are secure web gateways similar to firewalls?

There is an overlap in terms of the functionality of secure web gateways and firewalls, to the point that some people confuse them. Yet these are dissimilar in several key aspects.

First, a secure web gateway is a proxy (opens in a new tab). This means it can stop or emulate traffic. This feature allows gateways to cut through more advanced threat vectors from the web. Firewalls, on the other hand, are generally less sophisticated and provide security at the level of a data packet that is checked for malware. (opens in a new tab). They are generally unable to block traffic or check objects or applications for their threat levels.

Secure web gateways operate at the application level and as such can deny access to sites and applications that they deem potentially harmful. They have blacklists and whitelists with stored keywords and connections and are able to restrict the functionality of regular operations such as managing data downloads.

Finally, secure web gateways are used to create and enforce security rules and policies for various users, which is not the case with firewalls.

What about cloud access security brokers?

Like firewalls, cloud access security brokers (CASBs) are another piece of technology often confused with secure web gateways. In fact, these two complement each other more than they overlap, but fundamental similarities are shared. Still, in general, secure web gateways are more focused on keeping your traffic clean and logging everything that happens through it, while CASBs provide greater visibility into the overall security status of a system. . Additionally, CASBs focus more on what happens with your applications and have more control over them than SWGs.


Secure web gateways have managed to fit firmly into the modern security landscape, primarily due to the increased public interest in anything cloud-based. The changing perception of what these systems can do and the general maturing of the technologies that make them up have shattered the enduring charm of the antivirus-firewall combo as the security backbone of a bygone era. With the meteoric rise in the volume of web traffic and the number of connected devices, secure web gateways have proven capable of closing the majority of newly emerging security vulnerabilities and have remained a force to be reckoned with in a world of web security.


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