Security Glossary: Zero Trust

What Are Zero Trust Networks?

Zero Trust Networks represent a paradigm shift in the approach to cybersecurity, moving away from traditional defenses that focused primarily on securing the network perimeter. This concept, first outlined by Forrester in 2010, is grounded in the principle of “never trust, always verify.” It challenges the conventional “moat and castle” strategy which assumed that threats are primarily external and that anything within the network perimeter can be trusted.

In traditional network security models, the emphasis was on building strong external controls (like firewalls and antivirus software) to prevent attackers from penetrating the network. This approach operated on the belief that once inside the network, users and devices were generally trustworthy. However, this led to a significant vulnerability: once attackers breached the perimeter, they could move laterally within the network with little resistance, accessing sensitive data and causing substantial damage.

Zero Trust Networks, in contrast, operate under the assumption that threats can exist both outside and inside the network. This model treats every user, device, application, and system as potentially compromised, regardless of their location relative to the network perimeter. Under Zero Trust, trust is never assumed and must be continually earned. Every request for access to resources is thoroughly validated before being granted, irrespective of the requester’s location or credentials.

A key component of Zero Trust architecture is the use of microperimeters, which are small, localized boundaries placed around sensitive and critical assets. This method significantly reduces the attack surface by ensuring that access to crucial resources is tightly controlled and monitored. It prevents the lateral movement of attackers within the network, as gaining access to one part of the network does not automatically grant access to others.

Implementing Zero Trust Network security often involves advanced segmentation technology, which allows for precise control and monitoring of traffic within the network. This technology is integral in creating and managing microperimeters and in enforcing strict access controls based on user identity, device, location, and other factors.

In summary, Zero Trust Networks mark a fundamental shift towards a more holistic and dynamic approach to cybersecurity. By assuming that every component of the network could be compromised and enforcing rigorous verification, Zero Trust Networks aim to provide robust security in an increasingly complex and threat-prone digital landscape.