B92 Protocol: Two-State Quantum Key Distribution

This simulator plays out the B92 quantum key distribution protocol photon by photon in 3D. Alice encodes each bit into one of two non-orthogonal polarization states, Bob randomly picks a measurement basis for every incoming photon, and only the roughly one-in-four photons that yield a logically conclusive outcome are kept as sifted key bits — everything else is discarded live, in view. Flip on the intercept-resend eavesdropper to see how the no-cloning theorem forces Eve's own measurement to leak into the channel as a rising quantum bit error rate, the exact fingerprint Alice and Bob use to catch her.