Zero Trust is a security concept based on the principle:

"Never trust, always verify."

Unlike traditional security models that automatically trust internal network traffic, Zero Trust assumes that every user, device, and application must be authenticated, authorized, and continuously monitored — regardless of whether they are inside or outside the network perimeter.

🔐 Core Principles of Zero Trust

1. Verification over Trust
   No one is trusted by default — every user, device, and service must prove who they are.

2. Least Privilege Access
   Users and services only get the minimum access they truly need — nothing more.

3. Continuous Validation
   Trust is not permanent — it’s reevaluated continuously (based on behavior, location, device status, etc.).

4. Micro-Segmentation
   The network is divided into small, isolated zones to prevent lateral movement if an attacker breaks in.

5. Centralized Visibility & Logging
   Every access attempt is logged and monitored — critical for audits, compliance, and detecting threats.

🧱 Technical Implementation (Examples)

• Multi-Factor Authentication (MFA)

• Identity & Access Management (IAM)

• Device Posture Checks (e.g., antivirus, patch status)

• ZTNA (Zero Trust Network Access) as a VPN replacement

• Micro-segmentation via cloud firewalls or SDN

• Security Monitoring Tools (e.g., SIEM, UEBA)

🎯 Why Is Zero Trust So Important Today?

• Remote Work: Employees work from anywhere — not just inside a "trusted" office LAN.

• Cloud & SaaS adoption: Data lives outside your data center.

• Evolving Threat Landscape: Ransomware, insider threats, social engineering.

✅ Real-World Example

Without Zero Trust:

A user logs in via VPN and has full network access, just because they're "inside".

With Zero Trust:

The user must verify identity, device health is checked, and access is limited to only necessary apps — no blind trust.

🧪 Summary

Zero Trust is not a single product — it's a security strategy. Its goal is to reduce risk by enforcing continuous verification and minimizing access. When done right, it can drastically lower the chances of data breaches, insider threats, and lateral movement within a network.

Least Privilege is a fundamental principle in IT and information security. It means:

Every user, system, or process should be granted only the minimum level of access necessary to perform its duties—no more, no less.

Why is it important?

The principle of least privilege helps to:

• Minimize security risks: If an attacker compromises an account, they can only access what that account is permitted to.

• Prevent accidental errors: Users can’t unintentionally change critical systems or data if they don’t have access to them.

• Meet compliance requirements: Many standards (e.g., ISO 27001, GDPR) require access control based on the least-privilege model.

Examples:

• An accountant has access to financial systems but not to server configurations.

• A web server process can write only in its own directory, not in system folders.

• An intern has read-only access to a project folder but cannot modify files.

How to implement it:

• Role-Based Access Control (RBAC)

• Separation of admin and user accounts

• Time-limited permissions

• Regular access reviews and audits