BB84 Quantum Key Distribution: Photons, Eavesdropping & Latency (2D)

This 2D companion turns "quantum communication" into the actual protocol behind it — BB84 quantum key distribution — instead of a rotating scene of unlabeled 3D props. Polarized photons stream from Alice to Bob across a lossy fiber whose attenuation and propagation delay depend on the distance you set; a channel-noise slider adds baseline dark-count errors, and an intercept-resend eavesdropper you can dial in from 0–100% shows up not as a hidden threat but as a directly measurable rise in the quantum bit error rate, driving the live Shor–Preskill secure-key-rate readout toward zero as it crosses BB84's 11% abort threshold.