What Is Cryptography?

Cryptography is basically the art of secret messaging – like writing a diary in a language only you and your bestie understand. In fact, it literally means “hidden writing.”

In simple terms, cryptography turns your message into unreadable gibberish (ciphertext) until someone with the right key unlocks it.

🔑 Two Main Flavors:

Symmetric Cryptography:
One shared secret key is used to both encrypt and decrypt. Fast and great for big data, but the key must be shared secretly.
Asymmetric Cryptography:
Uses a public key (to lock) and a private key (to unlock). Anyone can send you a secure message using your public key, but only you can open it with your private key. No key sharing needed!

Where You See It Every Day 🔎

Cryptography isn’t just for spies—it’s hiding in plain sight:

🔒 HTTPS / Secure Websites
That padlock icon in your browser? That’s crypto in action, securing your logins and shopping data with TLS (which uses both symmetric and asymmetric crypto).
🗝️ Password Managers
Vaults like Bitwarden or 1Password encrypt your stored credentials. Even if a hacker breaks in, all they get is scrambled nonsense.
📱 Messaging Apps
WhatsApp, Signal, and Telegram use end-to-end encryption so only you and your friend can read the chat—not even the app’s servers can peek.
💳 Online Payments & Banking
When you enter card info online, it's encrypted using standards like AES or RSA, keeping it out of a cybercriminal’s reach.

Modern Algorithms in Use ⚙️

Here are the MVPs of modern-day cryptography, explained without jargon:

🔐 AES (Advanced Encryption Standard) – Symmetric

Used in Wi-Fi security, VPNs, encrypted SSDs, etc.
Encrypts data in 128-bit blocks using 128, 192, or 256-bit keys.
💪 AES-256 is basically uncrackable via brute force.

🔐 RSA – Asymmetric

The OG public-key encryption from the 1970s.
Encrypt with public key, decrypt with private key.
Used in TLS, SSH, PGP, digital signatures.
📉 Slower, and needs bigger keys (2048+ bits) to stay secure.

🔐 ECC (Elliptic Curve Cryptography) – Asymmetric

Modern and mobile-friendly.
Much smaller keys than RSA with equal security (e.g. 256-bit ECC ≈ 3072-bit RSA).
Used in Bitcoin, Signal, and modern TLS certs.

🔁 SHA-256 (Secure Hash Algorithm) – Hash Function

Not encryption, but creates a fixed-length fingerprint of your data.
Used for verifying integrity (checksums), storing passwords securely, and powering blockchain tech like Bitcoin.
🔁 One-way only—you can’t reverse a SHA-256 hash back to the original data.

TL;DR 🚀

Cryptography isn’t just some nerdy side quest. It’s the tech that:

Protects your Wi-Fi
Secures your passwords
Encrypts your messages
Powers cryptocurrencies
And makes the internet safe to use

Whether it’s AES scrambling your Wi-Fi traffic or SHA-256 validating your Bitcoin block, crypto is doing the hard math so you don’t have to.

🔍 Tools Behind the Blog:
Python, OpenSSL, Wireshark (for fun!), and endless curiosity.

🔐 Crypto is My guy (for Keeping Secrets)