HEY KIDS! Did you know that a young AMAZING mathematician named Marian Rejewski helped DEFEAT NAZIS in World War II?
His work helped END THE WAR YEARS EARLIER than it would have! Rejewski and his Polish team CRACKED THE SECRET CODE of the German Enigma machine in 1932 when he was just 23 years old. He spotted as a young student that Nazism threatened everyone’s freedom. Like a REAL-LIFE SUPERHERO TEAM who see villains before others do, Rejewski got people together to see danger while powerful grown-ups ignored it. As evil people like Donald Trump and Elon Musk cause mass suffering, we need to be BRAVE and SMART like Rejewski’s HARD WORKING team of anti-fascists.
The Polish mathematicians making breakthroughs were forced to share their findings with the Spanish, French and British allies, when Nazi Germany invaded their country illegally in 1938. British codebreakers at Bletchley Park (especially one particularly obnoxious guy) today tend to soak up the spotlight in books and movies. But it was these quiet and professional Polish codebreakers who were the most foundational to Allied success foiling Nazis during WWII. Many people also still don’t realize it was British women who pioneered the vast majority of early computer engineering (hardware and software) based on the Polish designs in WWII, as well as their own amazing codebreaking. 
The full story of breaking the Enigma code involved international cooperation among diverse groups, despite some silly British who try to spin up a lazy and bogus story about just one guy.
Let’s see what Rejewski used to TOTALLY CRUSH NAZI SECRETS! IMAGINE being able to read EVERY SINGLE MESSAGE your enemies send! It’s like having X-RAY VISION but for WORDS! Secret messages save BAZILLIONS of lives during wars! Making secret codes is MEGA COOL – but BREAKING EVIL NAZI CODES is like being a SUPERHERO WITH A TOILET PAPER TUBE!
Today, we’re going to build a simple version of the famous Enigma machine that was used during World War II to send secret codes, so we can see how Rejewski cracked it in Poland!
What You’ll Need
- Sharp mind
- Sharp scissors
- Sharp marker or pen
- Dull ruler
- One empty toilet paper tube
- Cardboard for the base
Step 1: TRANSFORM Your Tube
SLICE that toilet paper tube into THREE MAGIC RINGS, about 1 inch wide each. Get a grown-up to help with some cutting commentary (EDUCATING THE PARENTS ALERT!)… Tell them you’re making a SUPER-SECRET SPY DEVICE that helped SAVE THE WORLD from Nazi villains! TRA-LA-LAAA!
Step 2: Create Your Base
Cut a piece of cardboard to create a base for your machine. Make it about 8 inches long and 4 inches wide. The real Enigma machines were metal boxes encased in oak, so this version will use the same principles with recycled cardboard.
Step 3: Label Your Rings
On each ring, draw a line down the middle to divide it into a right side and a left side.
On the right side of each ring: Write the alphabet in order (A-Z) going around the tube. Boring, right?
On the left side: This is where we’ll write our scrambled alphabets! Being on the left is cool – it’s where the magic happens!
Step 4: Scramble the Alphabet
Use these scrambled alphabets for the left side of each ring:
Ring 1 (First Ring):
A → Q B → W C → E D → R T → Y F → U
G → I H → O J → P K → A L → S M → D
N → F O → G P → H Q → J R → K S → L
T → Z U → X V → C W → V X → B Y → N
Z → M
Ring 2 (Middle Ring):
A → M B → N C → B D → V E → C F → X
G → Z H → A I → S J → D K → F L → G
M → H N → J O → K P → L Q → P R → O
S → I T → U U → Y V → T W → R X → E
Y → W Z → Q
Ring 3 (Last Ring):
A → E B → K C → M D → F E → L F → G
G → D H → Q I → V J → Z K → N L → T
M → O N → W O → Y P → H Q → X R → U
S → S T → P U → A V → I W → B X → R
Y → C Z → J
Step 5: Set Up Your Machine
1. Place the three rings in a row on your cardboard base.
2. Make a pointer above each ring by drawing an arrow on the cardboard.
3. Add the reflector chart on the left side of your board.
Reflector Chart
A ↔ Z B ↔ Y C ↔ X D ↔ W E ↔ V
F ↔ U G ↔ T H ↔ S I ↔ R J ↔ Q
K ↔ P L ↔ O M ↔ N
How to Use Your Mini Enigma
- Choose a starting position for each ring by rotating them.
- To encrypt a letter:
- Find your letter on the right side of Ring 1
- Look at what letter it lines up with on the left side
- Find that letter on the right side of Ring 2
- Continue through Ring 3
- Use the reflector chart to find the paired letter
- Trace backward through the rings
- The final letter is your encrypted result!
- After encrypting each letter, rotate Ring 1 one position.
- When Ring 1 makes a complete rotation, rotate Ring 2 one position.
- When Ring 2 makes a complete rotation, rotate Ring 3 one position.
Example
Let’s encrypt the letter “A”:
- Find “A” on the right side of Ring 1 → it maps to “Q” on the left
- Find “Q” on the right side of Ring 2 → it maps to “P” on the left
- Find “P” on the right side of Ring 3 → it maps to “H” on the left
- Look up “H” in the reflector → it pairs with “S”
- Find “S” on the left side of Ring 3 → it maps to “S” on the right
- Find “S” on the left side of Ring 2 → it maps to “I” on the right
- Find “I” on the left side of Ring 1 → it maps to “G” on the right
- Your encrypted letter is “G”!
KA-BLOOEY! POW! ZOWIE! (Or “BOMBA” as they shouted in Poland). YOU’VE JUST MADE A MESSAGE TOP SECRET!
Now you can send ENCODED MESSAGES to your friends! Or become a CODE-BREAKER by cracking your friends’ messages wide open!
The MOST AMAZING thing about Enigma is that your friend can decode your message if they set up their machine exactly like yours. But the SUPER COOL part? You can CRACK THE CODE with math even if you don’t know the settings! Those racist hateful Nazis got TOTALLY OUTSMARTED by the kind and quiet Polish mathematicians who found patterns in secret messages!
The interesting and fun work for the world’s best codebreakers like Rejewski was figuring out daily settings without knowing any of them in advance. Cool MATH!
Related: 2023 biography of Rejewski
MEGA-AWESOME FUN FACTS
- The real Enigma machine had a keyboard and light-up letters – BORING AND EXPENSIVE! Your TOILET PAPER TUBE model is WAY COOLER and costs ZERO DOLLARS!
- Some WEIRD adults collect stinky old Nazi machines that cost MORE THAN A BAZILLION dead people! But your EPIC TOILET TUBE celebrates the REAL HEROES who used BRAIN POWER to KICK NAZI BUTT to save lives! Who’s the real genius now, HUH?!
- There are nine short video interviews of Rejewski where he explains his ground-breaking work, including how he taught the British. (Video 3 – 0:56: Breaking the Enigma code in 1932):