CipherForge

Welcome to the agency, recruit. Learn the secret art of cryptography — build and break codes from the ancient Caesar cipher toward the encryption that guards the whole internet.

Level 1

Work the ciphers

Three hands-on spy tools — the same cryptography as the app, rebuilt for the browser.

🔐 Cipher Workbench Type a message, pick a cipher, turn the dial — watch it scramble and unscramble. A free code lab with a spinning Caesar wheel. 🕵️ Code-Breaking Arena Crack an intercepted message. Read its letter fingerprint, slide the shift until it reads like real words, and lock in your answer. 🔎 Cipher Detective A code with no label. Which cipher made it? Read the clues in its fingerprint and name the cipher family. 🧩 Cryptogram No key this time. Every letter is swapped for another — crack it using letter counts and short words, the way real code-breakers do. 🔣 Symbol Ciphers Pigpen, Polybius, and Morse. Each secret symbol maps to exactly one letter — decode the message by reading the key. ➗ Affine Cipher Math meets code: E(x) = (a·x + b) mod 26. Multiply, add, wrap around 26 — and discover why the multiplier must be coprime to 26. 🫥 Null Cipher & Acrostics Hide a message in plain sight. The real words are the first letter of each word — or each line. Here the secret is the pattern, not the swap.

Learn the craft

16 kits from the basics of secret codes up to real cybersecurity — a short round of questions with a hint whenever you get stuck. Your progress stays on this device.

Kit 1: Secret Messages Basics Cryptography Basics · grades 4-5 · 25 questions Kit 2: Caesar & Substitution Ciphers Classical Ciphers · grades 4-5 · 25 questions Kit 3: Frequency Analysis Frequency Analysis · grades 5-6 · 25 questions Kit 4: Transposition Ciphers Transposition Ciphers · grades 5-6 · 25 questions Kit 5: Number-Based Codes Number-Based Codes · grades 5-6 · 25 questions Kit 6: Modern Encryption Concepts Modern Encryption · grades 6-7 · 25 questions Kit 7: Steganography & Information Hiding Hiding Information · grades 6-7 · 25 questions Kit 8: Cryptography in Daily Life Cryptography in Daily Life · grades 7-8 · 25 questions Kit 9: Classical Cipher Systems Classical Ciphers · grades 4-5 · 25 questions Kit 10: Modern Cryptography Basics Modern Encryption · grades 4-5 · 25 questions Kit 11: Codebreaking Techniques Codebreaking · grades 4-5 · 25 questions Kit 12: Cybersecurity Foundations Cybersecurity · grades 4-5 · 25 questions Kit 13: Cross-Topic Connections Cryptography Basics · grades 5-6 · 25 questions Kit 14: Real-World Applications Real-World Applications · grades 6-7 · 25 questions Kit 15: Misconceptions & Reasoning Cryptography Basics · grades 6-7 · 25 questions Kit 16: Advanced Synthesis Cryptography Basics · grades 7-8 · 25 questions
CipherForge mascot

Meet the cast — the characters who teach this

Each one stands for an idea you’ll practice. Tap a character to read their illustrated story and hear their audio drama.

Explore all the stories →

Privacy & how it works