BB84 Kid Quest 🧪🔑

You are Alice. Pick a secret bit (0/1) and a “magic lens” (basis ➕ or ✖). Send a photon to Bob, who measures with a random lens. If your lenses match, you keep that bit for your shared secret key!

Goal: Build a key

Alice (You) 🐰 Step 1/4

🐰
Pick a bit + basis Bit is 0 or 1. Basis is ➕ or ✖.
0️⃣
Bit = 0 Like “off” / “no” / “left”.
1️⃣
Bit = 1 Like “on” / “yes” / “right”.
➕
Basis = ➕ “Straight” lens.
✖
Basis = ✖ “Diagonal” lens.
Tip: If Bob uses the wrong lens (basis), his measurement becomes random.

Quantum Channel 🌌 Animated

from Alice to Bob
⚛️
Ready! BB84
Pick a bit and a basis, then encode and send.

Bob 🤖 Waiting…

🤖
Bob measures randomly He picks ➕ or ✖ and measures.
Bob's chosen basis —
Bob's measured bit —
Fun fact: Wrong basis → random result 🎲