Beginner
Free
4 modules · 12 lessons
Understanding Cryptography
Build real intuition for hashing, keys and signatures — from first principles to practical use, with interactive labs at every step.
What you will learn
- Explain what a cryptographic hash does and why it matters
- Read and compare SHA-2 digests and understand the avalanche effect
- Distinguish hashing from encryption — and passwords from both
- Reason about key pairs, digital signatures and HTTPS
- Pick the right primitive: hash, HMAC, AES-GCM, Ed25519 or Argon2
About this course
Cryptography is the invisible infrastructure behind secure software and every blockchain. This course starts with intuition and adds technical depth gradually: every concept comes with a figure, a real-world example, an interactive lab and a knowledge check.
You will finish able to choose the right primitive for a given job and to recognise the mistakes that get systems broken.
Curriculum
Hash functions 4 lessons
- What is hashing? Lesson · 10 min
- SHA-256 Lesson · 12 min
- The avalanche effect Lesson · 10 min
- Hash collisions Lesson · 12 min
Encryption 3 lessons
- What is encryption? Lesson · 12 min
- Symmetric encryption & AES-GCM Lesson · 15 min
- Hashing vs encryption Lesson · 10 min
Keys & signatures 3 lessons
- Public key cryptography Lesson · 15 min
- Digital signatures Lesson · 15 min
- How HTTPS keeps you safe Lesson · 12 min
Using cryptography well 2 lessons
- Choosing the right primitive Lesson · 10 min
- Common mistakes Lesson · 10 min