TLS

TLS (Transport Layer Security) secures application traffic over TCP networks and is the foundation of HTTPS and many secure application protocols.

Features

Encryption
Authentication
Integrity validation
Certificate-based trust
Perfect Forward Secrecy

Common Protocols Using TLS

Protocol	Usage
HTTPS	Secure web
SMTPS	Secure email
FTPS	Secure file transfer
MQTT TLS	IoT security

TLS Handshake

sequenceDiagram
    participant Client
    participant Server

    Client->>Server: ClientHello
    Server->>Client: ServerHello + Certificate
    Client->>Server: Key Exchange
    Server->>Client: Secure Session Established

Topics Covered

OpenSSL
TLS certificates
Certificate Authorities
CSR generation
Cipher suites
TLS debugging
HTTPS testing

Example OpenSSL Test

openssl s_client -connect google.com:443

Warning

Self-signed certificates are suitable for labs but not production environments.