A
Alice
her point of view
shared secret (Alice's copy)
no secure channel yet — establish a key
QUANTUM CHANNEL
👁️
EVE
⚠ EAVESDROPPER DETECTED
key discarded — nothing sent
idle
EVE
eavesdropper on the channel
🕵 SPY REPORT
run an exchange to see what the eavesdropper gets
CLASSICAL CHANNEL (public)
B
Bob
his point of view
shared secret (Bob's copy)
no secure channel yet — establish a key