Which security approach assumes no actor or system within the network is trusted by default?

• A. Network Segmentation
• B. Multi-Factor Authentication
• C. Data Encryption
• D. Zero Trust Model

Answer: (D)

Zero Trust is a security approach that assumes no actor or device inside or outside the network is trusted by default. Instead of granting broad access based on location or network segment, every access request is treated as potentially hostile and must be verified and authorized each time. This means confirming identity, checking device health and posture, evaluating risk context (such as location, behavior, and time), and applying the principle of least privilege so users and systems only get the minimum access they need for a short, defined period. Access decisions are dynamic and continuously reevaluated as conditions change, and micro-segmentation helps limit what a compromised account or device can reach by isolating workloads.

This model is especially effective in environments like CIAM, where multiple external identities and services require strict, ongoing access control. It contrasts with traditional networks that trust insiders after they’re inside the perimeter, which can allow lateral movement if credentials are compromised. While other controls like network segmentation, MFA, or encryption are valuable, they don’t by themselves establish a no-trust, continuous-verification posture. Zero Trust directly addresses the default-trust assumption and enforces verification for every access request.