Cryptography Explained: A Beginner's Guide to Digital Security
Understand the fundamental concepts of cryptography, from historical ciphers to modern encryption, to secure digital data and communications.
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About this course
Course contents
6 modules · 30 lessons · 3h
1
Introduction and History
Understand the basics of security and the origins of cryptography.
- The Three Pillars: CIA
Define Confidentiality, Integrity, and Authenticity as the goals of cryptography.6 min - The Caesar Cipher
Understand the concept of simple substitution through history.6 min - The Vigenère Cipher
Discover how complexity increased with polyalphabetic ciphers.6 min - From Analog to Digital
Explain the transition from physical machines to computer algorithms.6 min
2
Symmetric Encryption
Master how single-key encryption works.
- The Shared Key Concept
Using a single key to lock and unlock information.6 min - The Importance of Secrecy
Why security relies entirely on protecting the key.6 min - Introduction to AES
Introduce the modern standard for symmetric encryption.6 min - The Distribution Challenge
Explain why sharing a secret key remotely is risky.6 min - Use Case: Encrypting Your Hard Drive
A concrete example of using symmetric encryption.6 min
3
Asymmetric Encryption
Understand the revolution of public/private key pairs.
- The Duo: Public Key and Private Key
The mailbox analogy to explain the two keys.6 min - Simplified Technical Operation
How one key encrypts what only the other can decrypt.6 min - The RSA Algorithm
An introduction to the first mainstream asymmetric system.6 min - Symmetric vs. Asymmetric
Compare the speed and practicality of both methods.6 min - Hybrid Encryption
How asymmetric encryption is used to exchange a symmetric key.6 min
4
Hashing and Integrity
Learn how to ensure that data has not been modified.
- What is a Hash?
The digital fingerprint analogy.6 min - Properties of a Hash Function
Determinism, speed, and collision resistance.6 min - Verifying File Integrity
How to tell if a download has been corrupted.6 min - Securing Passwords
Why passwords are never stored in plain text.6 min - Examples: SHA-256 and Beyond
An overview of current hashing algorithms.6 min
5
Signatures and Authenticity
Prove the sender's identity and prevent repudiation.
- Creating a Digital Signature
Combining hashing and a private key to sign a document.6 min - Verifying Authenticity
Using the public key to confirm the origin of a message.6 min - Non-repudiation
Why you cannot deny having signed a digital document.6 min - Digital Certificates
The digital ID card for websites.6 min - Certificate Authorities
The role of trusted third parties in key distribution.6 min
6
Protocols and Real-World Security
See how everything comes together to protect our daily exchanges.
- The TLS/SSL Protocol
How HTTPS uses everything we've learned.6 min - The Browser Padlock
Interpreting security signals while browsing.6 min - Vulnerability: Weak Keys
Why key length and quality matter.6 min - Man-in-the-Middle Attack
Understand how an attacker can intercept a connection.6 min - Best Practices: Updates
The importance of using non-obsolete algorithms.6 min - Choosing Your Tools
Tips for using end-to-end encrypted services.6 min
Designing a Secure Communication Channel
You must diagram the steps necessary to send an ultra-confidential message to a friend. You will need to choose the right tools (symmetric, asymmetric, hashing) to ensure the message is secret, hasn't been modified, and that your friend knows it truly comes from you.
What you'll get
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Short & focused
3h of practical content
Certificate of completion
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Frequently asked
What do I need to take this course? +
Just a phone or computer with internet. No installs, no special hardware.
How do I pay? +
By card via Stripe. We don’t store card details — Stripe handles them securely.
Can I get a refund? +
Yes — full refund within 14 days, no questions asked.
How long will I have access? +
Forever. Once you purchase, the course is yours to revisit anytime.
Will I get a certificate? +
Yes. On completion you'll receive a certificate you can add to your LinkedIn profile.
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