Traditional perimeter-based security models create a "hard shell, soft center" approach where:

• Trust is based on network location (inside = trusted, outside = untrusted)
• Security controls focus on the network perimeter
• Internal traffic is largely unmonitored
• VPNs provide broad network access once authenticated
  Zero-Trust eliminates the concept of trusted networks by:
• Treating all networks as untrusted, including internal ones
• Authenticating and authorizing every connection attempt
• Implementing microsegmentation to limit lateral movement
• Continuously monitoring all network traffic and user behavior
• Providing conditional access based on risk assessment
  This shift addresses modern threats like insider attacks, compromised credentials, and advanced persistent threats that traditional perimeter defenses struggle to detect.