Part 1: Basic HTTP Authentication — a client and a server exchanging HTTP messages step by step: the 401 challenge, the password in every request, and what a session cookie adds
Part 2: Cookies and Sessions — a form login, the cookie that carries the session from then on, and the record behind it, in the server's memory or in Redis: expiry, logout, restarts, HttpOnly and Secure
Part 3: TLS Concepts — the ideas behind TLS as a role-play: the CA vouches for a name, the server proves it holds the key, the browser checks, and an impostor tries four ways past it; only the server has to prove who it is
Part 4: TLS in Action — the TLS 1.3 handshake record by record, the checks a browser or curl makes on the certificate, and what an eavesdropper copying the wire learns: self-signed, expired, wrongly named and stolen certificates, -k and --cacert
Part 5: Bearer Tokens — a password once, then a signed JWT in an Authorization header: the checks a service runs on it, a second service checking it with only the public key, a forged role, alg none, expiry, and logout against a copy of the token, with and without a revocation list in Redis
Part 6: OAuth2 — a print shop gets a token to alice's photos at another service without her password: the authorization code flow message by message, front and back channels, state and PKCE, scope, refresh tokens, and removing the app's access
Part 7: OpenID Connect (OIDC) — a print shop signs alice in with her photos.example account: OAuth2 plus an ID token, the checks the app runs on it, discovery and JWKS, the ID token refused at the API, single sign-on, and a key rotation
Authentication and Secrets — how a request proves who sent it, from a password in a header to a workload that never holds one: Basic auth and sessions, keys and signatures, TLS and certificate chains, mTLS, JWT, OAuth2 and OIDC with Keycloak, and secrets with Vault and AWS. An interactive course, worked in your own terminal with Docker.
TCP Simulator — two hosts exchanging segments step by step: open, send, lose, retransmit and close, with every ACK tied to the segments it acknowledges, and TCP in short lines beside it
NAT
NAT Overload Simulator — a home router sharing one public address, its NAT table filling and ageing as packets cross it, with the private address ranges and NAT's other names