Zero Trust VPNs (virtual private networks) are an IT security solution that requires strict identity verification before a user is allowed access to a private network, whether the person is outside or already inside the network. 

Zero Trust VPNs are all about preventing potential breaches by limiting access paths, making it harder for threats to move laterally within the network. Controlled and careful, every step is about maintaining security and minimizing unnecessary exposure.

Imagine a building where every door needs a separate key. Even if you have the main entrance key, you can't just wander around freely. Zero Trust VPNs work similarly. They verify every connection, ensuring that each access request is legitimate or even necessary.

Never trust, always verify

Zero Trust VPNs work on the core mantra of ‘never trust, always verify’. Essentially, it compels network administrators to trust no one.

Traditional VPNs often rely on a single point of access validation. Zero Trust VPNs, though, enforce continuous verification, at every step, for every user and every device. 

Picture yourself working in a company where you access the network from multiple devices – a laptop, a tablet, and your smartphone. In a conventional VPN setup, once you're in, you're trusted throughout your session. 

Not so with a Zero Trust VPN. Every time you switch from your laptop to your phone, a Zero Trust VPN will re-authenticate your identity and the safety of your device, ensuring no malicious actor can slip through. So, even if a device is compromised, the system can catch the intruder in real-time and block access.

Zero Trust VPNs also employ machine learning to detect unusual behavior. Let’s say you have been accessing the network from your home country and suddenly, your login attempt comes from a country halfway across the globe. The VPN will flag this as suspicious and request additional verification or even block the attempt outright.

Benefits of Zero Trust VPNs

Improved security

Traditional VPNs assume that once you’re inside the network, you’re trustworthy. In contrast, Zero Trust VPNs are suspicious of every user. This means every access request is authenticated and encrypted. 

Flexibility

Zero Trust VPNs don’t care where you are. Whether you're working from a coffee shop in Seattle or your living room, the security framework remains consistent. If other team members have to work remotely, their connections remain secure and uninterrupted.

Operational simplicity

Zero Trust VPNs often come with centralized management dashboards. You can monitor and control access in real time. That way you can see who is connected, from where, and to what resources without having to dive into complicated log files, which saves time and makes it easier to spot unusual activities.

Improved user experience

Zero Trust VPNs are optimized for performance, therefore, your internet speed never slows down. They adapt based on real-time conditions, ensuring that you get the fastest and most secure connection possible. 

Zero Trust VPNs vs Traditional VPNs

Traditional VPNs mainly focus on encrypting your internet connection. When you connect to a traditional VPN, it's like punching a secure tunnel through the internet to a server. This server then makes it appear as though your traffic originates from there. 

That works well for hiding your IP address and accessing geo-restricted content. However, it also makes a blanket assumption that once you're connected, you're trusted. This means, if a hacker somehow gains access to your VPN, they can roam freely inside your network.

Zero Trust VPNs take a different approach. Instead of trusting you just because you've connected, they continuously validate your identity and the security posture of your device. 

Consider a traditional VPN used in a corporate setting. Once connected, any employee can access the internal network, regardless of what device they're using. 

With a Zero Trust VPN, however, the network continuously checks if the device meets security standards, such as up-to-date antivirus software or enabled firewalls, before granting any access. If the device falls short, access is denied or limited.

Even after connecting, a Zero Trust VPN will still require the employee to authenticate for every other system they want to access. This means if their credentials are compromised, the damage is minimized.

Multi-factor authentication (MFA)

Real-world implementations of Zero Trust VPNs often use multi-factor authentication (MFA). Think of it as adding multiple locks to your front door. Every authentication factor the VPN asks for adds a layer of security that makes it much harder for unauthorized users to gain access. 

Each time you log in, MFA might request you to enter your password, a fingerprint scan, and a one-time code sent to your phone. This means if someone tries to hack into your account, they’d need all these authentication factors to succeed.

Many modern VPN services already support MFA. If yours does, enabling it is usually straightforward. You'll need an authentication app like Google Authenticator or Authy. Once enabled, every time you log in to the VPN, you'll enter your password and a code from your MFA app.

Most modern devices also support fingerprints or facial recognition. If your VPN client can integrate with these biometric systems, it can add another layer of convenience and security. 

MFA is a core tool of Identity and Access Management (IAM), which is backed into many Zero Trust VPNs. IAM ensures that every user and device is properly authenticated before granting access to sensitive resources. 

IAM also excels at automating user provisioning and deprovisioning. When someone joins the team, IAM can automatically set up their VPN access based on their role. It also provides the tools to track and analyze user behavior in real time, allowing the VPN to block access requests from strange places.

Likewise, when someone leaves, IAM ensures that their access is revoked immediately. This automatic management prevents lingering access that could be exploited maliciously.

IAM also simplifies device management by enforcing policies that only allow recognized, secure devices to access the VPN. Think of it as ensuring that every device meets certain security standards, like up-to-date antivirus software or disk encryption, before it can connect.

Access segmentation through role-based access control (RBAC)

Zero Trust VPNs segment network access based on roles and permissions. For example, a marketing professional does not normally need access to the company’s financial systems. A Zero Trust VPN ensures they are confined to the marketing domain, minimizing the risk of lateral movement if their credentials are somehow breached.

Another example of this segmentation is in healthcare, where patient data needs to be protected rigorously. Nurses might need instant access to patient records, but not to billing systems. Zero Trust ensures that nurses can only access what they need, without exposing sensitive financial data.

Modern Zero Trust VPN solutions are also designed to be unobtrusive, so all these additional steps don’t drastically affect your team’s productivity. They work seamlessly in the background, ensuring security without being a constant nag. 

Core tools and principles of Zero Trust VPNs

Assume a Breach

Traditional VPNs operate under the assumption that anyone inside the network can be trusted. However, this isn't the case anymore. By adopting a Zero Trust model, you operate with the mindset that your network is already compromised. In other words, no one gets a free pass.

A Zero Trust VPN trains network administrators to always assume a worst-case scenario, which forces them to be more vigilant. It prevents complacency and ensures that your security measures are always active, always scrutinizing, and always working to protect your assets.

By assuming a breach, you also pay more attention to logs and analytics. You don't just collect data; you actively analyze it. If you spot an anomaly, like a sudden spike in data downloads from a specific user, you investigate immediately. This proactive stance helps you catch issues before they spiral out of control.

Least Privilege Access

The principle of least privilege with a Zero Trust VPN creates a finely tuned security approach that minimizes risks and ensures every user and device operates within their designated boundaries. Every user or device should only have the minimal level of access necessary to perform their functions.

Consider a marketing team that needs access to customer analytics data but shouldn't have access to the server configurations of the website. By enforcing least privilege access, their VPN connections can be restricted to only the analytics server. They won’t even see the server configuration files, let alone access them.

Now, think about temporary or contract workers. They often join with specific, limited tasks like updating the website or handling customer queries for a peak period. 

Instead of granting them broad access, you can configure their VPN access to be temporary and highly specific. This could mean they only access the content management system or the customer service database they need for their tasks.

Even within teams, granular control is key. For instance, junior developers might only get read permissions on the code repository. Senior developers, who need to merge changes, get write access. This ensures that only trusted users can make significant changes to the codebase, reducing risks of accidental or malicious modifications.

Devices play a role too. A personal laptop connecting to the VPN should meet all compliance checks – like having the latest security patches and encryption. If it doesn't, it should be denied access. This way, you’re not just verifying the user but also the device's security posture.

Endpoint security

You can have the most secure network in the world, but if your endpoints aren't protected, it's all for nothing. In the Zero Trust model, you must assume that our endpoints could be compromised at any time and take steps to secure them.

For starters, every device—laptops, smartphones, tablets, you name it—needs to be authenticated with multi-factor authentication (MFA). Your devices must also be compliant with your security policies at all times. 

Encryption is also an essential tool for endpoint security. Not just on data at rest but also in transit. Imagine you're working from a coffee shop. Your endpoint security should ensure that all communications between your device and the VPN are encrypted. This way, even if someone intercepts the data, they can't read it. 

Also, consider mobile device management (MDM). Solutions like AirWatch or MobileIron enable you to secure, monitor, and manage mobile devices. You can enforce security policies, wipe data remotely, and ensure that only compliant devices access your network.

Software-Defined Perimeter (SDP)

An SDP is yet another tool crucial for implementing zero-trust security. Similar to how Role-Based Access works, a Software Defined Perimeter places security policies and controls around individual software and workloads. It's like having multiple smaller fences inside your yard, each securing a specific area.

For example, let's say you have a development team working remotely. With a traditional VPN, everyone on that VPN could potentially access the entire network. With an SDP, you can restrict access, so team members only reach the resources they need, like code repositories, without touching sensitive financial records.

SDP also enhances security by making unauthorized resources invisible. If something's not visible, it's much harder to attack. This is particularly useful for protecting APIs on the internet from unauthorized access. A server-to-server model in SDP can safeguard all APIs from unauthorized hosts.

Network Segmentation in Zero Trust VPNs

Network segmentation, often called macro segmentation, is a traditional method used to compartmentalize a computer network into distinct sections. Think of it as creating separate rooms within a building, each with its own security measures. This approach is essential for managing access and enhancing security.

Network segmentation involves using physical devices like firewalls, routers, and load balancers to divide the network logically, similar to setting up different floors with restricted access.

In a corporate setting, you might have different segments for the finance department, human resources, and general office staff. The finance segment would only be accessible to financial personnel, with a firewall ensuring that no unauthorized person can access sensitive financial data. Similarly, HR would have its segment, secured separately to protect employee information.

Another tool used for network segmentation is VLANs (Virtual Local Area Networks). These are logical segments within a network, kind of like creating virtual walls within an open office space. VLANs help us to manage and isolate traffic, ensuring that specific data flows only within its designated segment.

In a Zero Trust VPN setup, network segmentation boosts security by restricting access to certain segments, which minimizes the risk of an attack spreading across the entire network. If a hacker breaches one segment, they're confined to that area, unable to move laterally to other parts of the network.

How to implement a Zero Trust VPN

Implementing a Zero Trust VPN is about being cautious and proactive. It starts with understanding that traditional perimeter-based security models are outdated. It requires assuming that threats can come from anywhere, even inside the network. 

Start by ditching the old notion of a trusted internal network and segmenting the network into smaller, manageable pieces. For instance, separate the finance system from the HR systems. Give each segment its own set of rules and access controls.

Next, deploy multi-factor authentication (MFA) across the board. Ensure the system asks for a second form of identification. This could be something like a text message verification or a mobile app prompt. 

Also, make sure to encrypt all data that is in transit. Whether it’s a simple file transfer or a more complex API call, everything must be encrypted. This ensures that even if the data gets intercepted, it remains unreadable to unauthorized parties. Tools like SSL/TLS protocols are invaluable here.

Importantly, integrate continuous monitoring and logging into the system. By keeping an eye on all activities, you can detect anomalies early. Set up alerts for unusual behavior, such as a user accessing a system at odd hours or from a suspicious location. These real-time insights are critical for quick responses.

Additionally, embrace the least privilege principle. Users must only get access to the resources they need. Lastly, secure all endpoints. All devices connecting to the network have security measures in place, like antivirus software and firewalls. Make it a policy to keep software up to date to reduce vulnerabilities that could be exploited by threat actors.