Zero Trust vs. VPN vs. SDP: Which One Should You Choose?

The main differences between virtual private networks (VPNs), software-defined perimeters (SDP) and zero trust relate to the level of security each solution type offers. While zero trust and SDP secure identities based on modern architectures, VPNs are capable of tunneling in attackers.

Network and communication needs are rapidly changing and the number of sophisticated cyber security attacks is increasing. As a result, organizations are trying to find better cybersecurity solutions that will protect their networks, applications and information. Three of the most debated technologies are VPNs, SDPs, and zero trust (ZTNA or ZTA). This blog post will explain each one and when you should choose it for your organization.

What are VPNs?

VPNs were designed as a new remote access approach approximately two decades ago, when companies needed a solution for connecting branches or workers who were occasionally working remotely from a desktop computer. At the time VPNs originated, workers had far fewer devices - smartphones, tablets, etc. were still in the future. VPNs authenticate users from outside of the network, and then tunnel them inside. Once users are in, they can see and access the entire network. 

VPN traffic is often encrypted and is considered slow and plagued by latency. In addition, setting up VPNs is a difficult process that requires a lot of overhead from IT teams and users, as VPNs require setting up a client on the end-user's device.

But more importantly, VPNs are not a secure access solution. Their castle-and-moat approach and technical vulnerabilities that are common in VPNs makes them a component that increases the attack surface.

VPN Use Cases

VPNs can be used in organizations that require a limited extent of remote connectivity for their employees or branches. Capping the traffic will help with ensuring higher performance and reduce IT overhead. That being said, it is recommended to complement VPNs with another security solution, to protect from internal threats. 

What is Zero Trust?

Zero trust is a new security model that is based on the premise of trusting no one inherently. It assumes that attackers exist outside and inside the network. Therefore, even if a user was able to access the network (through VPN or any other manner) this does not mean they should see all the network assets or have automatic access to them. Instead, after an authentication at the network entry-point, users and devices get constantly authenticated and validated for each and every app, asset, network and environment they want to access. Instead of network segmentation, zero trust uses micro-segmentation.

But if this sounds like it creates a whole lot of overhead, this is not the case. Access policies are easily updated by the security team at any time. The zero trust network uses these policies to continuously and constantly validate access. Unvalidated user identities are blocked. Security teams can change permissions at the click of a button. In terms of performance, zero trust sits atop of the existing network, and can even be used on the public network. Therefore it does not gobble up bandwidth. 

ZTNA Use Cases

Zero trust use cases include all modern business requirements:

1. Employee access, including remote work for the entire workforce

2. Third party access

3. Privileged users access management

4. M&As

5. Developer access to production environments, protecting source code, and more

6. OT operations

What is SDP?

SDP (software defined perimeter) is also a newer security approach compared to VPNs. If VPNs were based on the network perimeter, SDP defines a new perimeter - one that is software based. This means that the perimeter functionality is given to internal software entities, like data centers, environments and even applications. Controllers are used for continuous authentication and validation of users to the network assets. In addition, the assets are hidden from anyone in the network, until they request specific access.

If this sounds similar to zero trust, you’re not wrong. SDP is the architecture on which zero trust principles are instated. Therefore, you might often see Zero Trust used interchangeably with SDP (though not so much the other way around).

SDP Use Cases

Equivalent with zero trust use cases, SDP use cases include remote work, connecting third parties to networks, OT, tech companies protecting their source code, M&As, and more. 

VPN vs. Zero Trust vs. SDP Comparison

Let’s see how these three technologies compare.