BB84 Protocol - Provably Secure Key Exchange
Click "Start New Exchange" to begin the protocol simulation
1. Quantum Transmission: Alice sends photons polarized according to random bits and bases.
2. Random Measurement: Bob measures with randomly chosen bases (correct basis = correct bit).
3. Basis Reconciliation: Alice and Bob publicly compare bases (not bits!) and keep only matching ones.
4. Eavesdropper Detection: Any interception disturbs quantum states, introducing detectable errors.
The security is guaranteed by quantum mechanics - measurement disturbs the state!