Security by Design

Authentication, authorization, encryption, secrets management, and architectural security patterns

110 minutes

10Detailed Sections

Senior Level

Authentication: prove identity (who are you). Authorization: determine access (what can you do).

Different mechanisms: password, multi-factor auth, biometrics, certificates. Different protocols: session cookies, OAuth 2.0, OIDC, SAML, mTLS.

Common flow: user provides credentials -> authenticate -> issue token -> use token for authorization. Failures: weak password policies, session fixation, token leakage.

Best practice: never store passwords in plaintext; use bcrypt, Argon2. Session tokens should be short-lived; long-term refresh tokens stored securely.

Real-world: Google uses OIDC; Stripe uses API keys; social logins use OAuth 2.0.

Key Takeaways

Authentication: Verify identity ("who are you?") via credentials or credentials

Authorization: Verify permissions ("what can you do?") after authentication

Password Security: Use bcrypt/Argon2 for hashing; never plaintext or reversible

Token Strategy: Short-lived access tokens + long-lived refresh tokens for balance

Multi-Factor Auth: Required for high-value accounts (admin, payments)

Logging: Never log passwords, tokens, or sensitive data; sanitize logs

Visual Diagram

User -> Credentials -> Authenticate -> Token -> Authorization checks

All Tutorials Practice Questions

Security by Design

Table of Contents

Authentication vs Authorization: Foundational Concepts

Key Takeaways

Visual Diagram

OAuth 2.0 and OpenID Connect Flows

JWT: Structure, Validation, and Security

mTLS and Zero Trust Architecture

Encryption: At Rest and In Transit

Secrets Management and Handling

OWASP Top 10 and Common Vulnerabilities

Security Headers, Rate Limiting, and DDoS Protection

Security Compliance and Real-World Lessons

Case Studies: Security at Scale and Compliance