What is Cryptography?

Cryptography is the science of protecting information by transforming it into a form that only authorized parties can read and verify.

What Cryptography Does

At its core, cryptography converts readable data, known as plaintext, into an unreadable format called ciphertext using mathematical algorithms and keys. Only someone with the correct key can reverse the process and recover the original message.

Why It Matters in Cybersecurity

Every secure login, encrypted file, and private message online depends on cryptography. It protects data in transit across networks and data at rest on servers and devices, forming the backbone of modern digital trust.

The Four Core Goals

Cryptography is generally built around confidentiality (keeping data secret), integrity (ensuring data isn't altered), authentication (verifying identity), and non-repudiation (preventing denial of an action). These goals guide how encryption, hashing, and signatures are used together.

Where Ethical Hackers Use It

Penetration testers regularly encounter cryptography when assessing password storage, VPN configurations, and encrypted communications. Understanding its fundamentals helps identify weak implementations that attackers could exploit.