Cryptography Essentials

Cryptography is the foundation of secure systems. Every time you deploy an application over HTTPS, store passwords, sign a container image, or encrypt secrets in your pipeline, you're relying on cryptographic primitives. Understanding how these work—and more importantly, how they can fail—is essential for building secure infrastructure.

This guide covers the cryptographic concepts that DevOps engineers encounter daily. We won't dive into the mathematics, but we'll give you the practical knowledge to make informed security decisions.

By the end of this guide, you'll understand when to use different encryption types, why some hashing algorithms are insecure, how TLS protects data in transit, and how PKI establishes trust.

What You'll Learn

This guide consists of the following parts:

1. Encryption - Symmetric vs asymmetric, common algorithms, key management
2. Hashing - Integrity verification, password storage, choosing algorithms
3. TLS/SSL - How HTTPS works, certificate types, common misconfigurations
4. PKI - Certificate authorities, trust chains, certificate lifecycle

Why Cryptography Matters for DevOps

Consider these real-world scenarios:

• A misconfigured TLS certificate causes a production outage
• Leaked API keys encrypted with a weak algorithm get decrypted by attackers
• A password breach exposes millions of users because MD5 was used for hashing
• A CI/CD pipeline is compromised because secrets weren't properly encrypted at rest

Each of these incidents could have been prevented with proper cryptographic knowledge. Cryptography isn't just for security specialists—it's a core competency for anyone building and operating modern systems.

Prerequisites

This guide assumes you have:

• Basic command-line familiarity
• Understanding of HTTP/HTTPS concepts
• Experience deploying applications (containers, cloud, or traditional)

No prior cryptography knowledge is required.

Who This Guide Is For

This guide is designed for:

• DevOps engineers managing certificates and secrets
• Developers implementing authentication and data protection
• Platform engineers building secure infrastructure
• Anyone preparing for security-focused interviews

Let's build your cryptographic foundation!