Authentication & Security
Secure your APIs with industry-standard patterns. JWT tokens, OAuth2, bcrypt password hashing, CORS, rate limiting, and OWASP Top 10 defences.
What you'll learn
Authentication & Security is organized into 5 focused modules. By the end you'll be comfortable with:
- Security Fundamentals
- Password Security
- JWT Authentication
- OAuth2 in FastAPI
- API Security Hardening
Course curriculum
29 lessons across 5 modules. Lessons marked Free preview are readable without an account.
Module 1. Security Fundamentals
Understand the most common web vulnerabilities and how backend engineers prevent them.
- 9mOWASP Top 10 OverviewFree preview
Meet the ten most common ways web apps get broken into — the shared vocabulary every backend engineer is expected to know.
- 10mInput Validation and SanitizationFree preview
Treat every byte from the client as hostile until proven safe — validate at the boundary, sanitize before output.
- 9mSecurity Headers
A handful of HTTP response headers turn the browser itself into your bodyguard — against clickjacking, MIME sniffing, and protocol downgrades.
- 9mCORS Explained
Why your React app can't call your API — and what CORS actually is (hint: it loosens a browser rule, it isn't access control).
- 8mSecrets Management
API keys, DB passwords, signing keys — where they must live (environment, secret managers) and what to do the instant one leaks.
- 8mPractice: Security Fundamentals
No new concepts — just reps. Diagnose real-world scenarios using everything from Module 1.
Module 2. Password Security
Hash passwords correctly with bcrypt and understand why plaintext or weak hashing is catastrophic.
- 8mWhy Hash Passwords?
Why a plaintext password column is a catastrophe waiting to happen — and what a one-way hash actually buys you.
- 10mbcrypt and Salting
The two properties that make bcrypt the right password shredder: a unique salt per password and a tunable cost that keeps it slow.
- 11mpasslib and FastAPI Integration
Wire bcrypt into real register and login endpoints — and close the timing leak that quietly reveals which emails have accounts.
- 9mPassword Policies and Account Lockout
Set sensible strength rules (length beats symbols) and stop online guessing cold with lockout and rate limits.
- 8mPractice: Password Security
No new concepts — just reps. Diagnose password-storage and login-defence scenarios from across Module 2.
Module 3. JWT Authentication
Implement stateless authentication with JSON Web Tokens — the industry standard for API security.
- 10mWhat Are JWTs?
The tamper-evident wristband model: what a JWT contains, why it can't be forged, and why anyone can still read it.
- 11mCreating and Verifying JWTs in Python
Issue a signed token at login and verify it on every protected request with a clean FastAPI dependency.
- 10mRefresh Tokens
Keep users logged in for weeks without long-lived access tokens — and get real logout back with a revocable refresh token.
- 9mJWT Security Best Practices
The pitfalls that turn a working JWT setup into a vulnerable one — starting with the infamous `alg: none` forgery.
- 10mRole-Based Access Control
Gate endpoints by role with a reusable dependency — and know when a JWT claim is good enough vs when to hit the DB.
- 8mPractice: JWT Authentication
Reps across the whole JWT module — structure, verification, refresh tokens, pitfalls, and roles.
Module 4. OAuth2 in FastAPI
Implement OAuth2 password flow and understand social login concepts (Google, GitHub).
- 10mOAuth2 Flow Overview
OAuth2 is a valet key, not a house key — the four grant types and which one 'Sign in with Google' actually uses.
- 11mFastAPI OAuth2 Password Implementation
Wire up the OAuth2 Password flow with FastAPI's built-in helpers — the standard shape for first-party login.
- 10mSocial Login Concepts
How 'Sign in with Google/GitHub' really works — and the golden rule: turn their identity into YOUR token.
- 9mScopes and Fine-Grained Permissions
Scopes are hotel keycards — each opens only certain doors. Grant the fewest a client needs (least privilege).
- 8mPractice: OAuth2
Reps across the OAuth2 module — flows, the Password flow, social login's golden rule, and least-privilege scopes.
Module 5. API Security Hardening
Harden your API against CORS misconfiguration, rate limiting abuse, HTTPS enforcement, and data exposure.
- 10mRate Limiting for Security
The turnstile that starves brute-force and abuse — tighter on sensitive routes, keyed by user where you can.
- 8mHTTPS and TLS Enforcement
Encrypt the pipe so credentials can't be sniffed — and know exactly what TLS does and doesn't protect.
- 8mData Exposure Minimisation
Return only what the caller needs — separate response models for public, private, and admin views.
- 9mCSRF Protection
When your auth lives in a cookie, another site can make the user's browser act for them. Meet CSRF — and why token auth mostly sidesteps it.
- 8mSecurity Logging and Monitoring
You can't respond to what you can't see. Log the security events that matter — and never the secrets.
- 8mBackend Security Checklist
The pre-ship review that ties every module together — one place to catch what you missed.
- 12mCapstone: Securing a Real Endpoint
One realistic secured API, built layer by layer — every module of this course visible in a single flow.
Frequently asked questions
- Is the Authentication & Security course free?
- You can preview lessons for free with no account. Full access to this Pro course is included with a Kodion Pro subscription.
- Do I need prior programming experience?
- This is a intermediate course, so you'll get the most from it if you're already comfortable with the basics of programming.
- How long does Authentication & Security take to complete?
- It's 29 lessons across 5 modules, roughly 4 hours of hands-on learning. You can go entirely at your own pace.
- What will I learn?
- You'll work through Security Fundamentals, Password Security, JWT Authentication, and more, building real, applied skills through interactive lessons and coding challenges.
- Can I get help if I'm stuck?
- Yes. Kodion's built-in AI tutor gives instant, context-aware hints and explanations right inside each lesson as you code.
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