Security Overview

Zero Trust Architecture

Zero Trust is a security paradigm built on the principle of "Never trust, always verify." Unlike traditional perimeter-based security (castle-and-moat), Zero Trust assumes that threats exist both inside and outside the network boundary. Every access request must be authenticated, authorized, and continuously validated regardless of where it originates.

The core tenet: no implicit trust is granted to any asset or user account based solely on physical or network location.

The Five Pillars of Zero Trust

Threat Modeling

Threat modeling is a structured approach to identifying, quantifying, and addressing security risks early in the design phase. It answers the question: "What can go wrong?"

STRIDE Threat Model

STRIDE is a mnemonic for six categories of security threats, developed by Microsoft:

Attack Surface Analysis

Every exposed interface is a potential attack vector. Key attack surfaces in cloud-native environments:

• External APIs & endpoints: Public-facing REST/gRPC APIs, load balancers, ingress controllers
• Container images: Vulnerable OS packages, application dependencies, secrets baked into layers
• IAM configurations: Overly permissive roles, unused credentials, unrotated keys
• Infrastructure code: Terraform modules, Helm charts, Kubernetes manifests with misconfigurations
• CI/CD pipelines: Third-party actions, build environment secrets, artifact integrity
• Supply chain: Open-source dependencies, container base images, third-party SDKs
• Metadata services: AWS IMDS, GCP metadata server — accessible from any EC2/GCE workload

Threat Actors

Security Frameworks Overview

NIST Cybersecurity Framework (CSF)

The NIST CSF provides a policy framework of computer security guidance for organizations. It is organized around five core functions:

CIS Controls v8

The CIS Controls (Center for Internet Security) are a prioritized set of 18 actions to protect against cyber attacks. They are grouped into three implementation groups (IG1, IG2, IG3) based on organizational maturity:

• IG1 (Basic Cyber Hygiene): Controls 1–6: Inventory, software inventory, data protection, secure configuration, account management, access control management
• IG2 (Foundational): Controls 7–16: Continuous vulnerability management, audit log management, email/browser protections, malware defense, network monitoring, network infrastructure, security awareness, service provider management, application software security, incident response
• IG3 (Organizational): Controls 17–18: Penetration testing, security awareness training program

ISO 27001 Key Domains

ISO/IEC 27001 is the international standard for Information Security Management Systems (ISMS). Annex A contains 93 controls organized into 4 themes:

Cloud Security Shared Responsibility Model

In cloud computing, security responsibilities are shared between the cloud provider and the customer. Understanding this boundary is critical — misconfiguration of customer-managed components is the leading cause of cloud security incidents.

Defense in Depth — Security Layers

Defense in Depth is a layered security strategy where multiple independent security controls are applied at different levels. If one layer fails, others continue to provide protection. This is analogous to a medieval castle with a moat, walls, towers, and guards — no single point of failure.

Key Security Principles

DevSecOps: Shift-Left Security

Shift-left means integrating security testing and controls as early as possible in the software development lifecycle — moving it "left" on the timeline from production back to design and coding. The cost of fixing a vulnerability found in production is 6–100x higher than finding it at the code level.

Next Steps

Explore the detailed topics in this Security section: