Which of the following best explains the importance of network microsegmentation as part of a Zero Trust architecture?

Network microsegmentation is a core component of a Zero Trust architecture. It involves dividing the network into small, isolated segments, often down to the individual workload level. The primary security purpose of this practice is to create a granular security perimeter around each segment. By doing so, if one segment is compromised, the security policies in place prevent the threat from moving laterally to other segments. This containment strategy, often referred to as limiting the "blast radius," is fundamental to the Zero Trust principle of assuming a breach has already occurred and minimizing its potential impact.

A. To allow policies that are easy to manage and less granular This is incorrect. Microsegmentation enables highly granular policies, which can increase management complexity, rather than making them easier or less granular.
B. To increase the costs associated with regulatory compliance This is incorrect. While implementation has costs, microsegmentation is designed to improve security, which typically helps in meeting, not increasing the cost of, regulatory compliance.
D. To reduce hardware costs with the use of virtual appliances This is incorrect. While microsegmentation often uses virtual appliances, which can reduce hardware costs, this is a secondary benefit. Its primary security importance is containment, not cost savings.

1. National Institute of Standards and Technology (NIST). (2020). Special Publication 800-207: Zero Trust Architecture. U.S. Department of Commerce. In Section 3.2.3

"Micro-Segmentation

" it states

"This is a security technique of creating zones in data centers and cloud environments to isolate workloads from one another and secure them individually... If a breach does occur in one microsegment

a micro-segmentation policy can help prevent an attacker from moving laterally to another." (Page 16).

Available at: https://doi.org/10.6028/NIST.SP.800-207

2. Kindervag

J. (2010). Build Security Into Your Network’s DNA: The Zero Trust Network Architecture. Forrester Research. This foundational paper on Zero Trust states

"The third tenet of Zero Trust is to create microperimeters... These are small segments of the network that are protected by a segmentation gateway (next-generation firewall)." This design is explicitly for controlling traffic and preventing unauthorized lateral movement. (Page 7).

3. Carnegie Mellon University Software Engineering Institute (SEI). (2021). A Quick Introduction to the Zero Trust Security Model. SEI Blog. The article notes that a Zero Trust architecture "leverages network microsegmentation... to prevent lateral movement from one part of the network to another in the event of a breach."

Available at: https://insights.sei.cmu.edu/blog/a-quick-introduction-to-the-zero-trust-security-model/