Learning Objectives

By the end of this chapter, you should be able to:

• Explain why encryption is essential on modern networks.
• Differentiate between SSL and TLS.
• Understand symmetric and asymmetric encryption.
• Explain the purpose of public and private keys.
• Understand how digital certificates establish trust.
• Explain the role of Certificate Authorities (CAs).
• Understand the certificate chain.
• Walk through the TLS handshake step by step.
• Explain Mutual TLS (mTLS).
• Understand certificate renewal and automation using Let's Encrypt.
• Explain certificate pinning.
• Troubleshoot common TLS and certificate-related issues in production.

Introduction

Every day, billions of people:

• Log in to their bank accounts.
• Purchase products online.
• Send emails.