What is QKD? What is quantum key distribution? What is quantum cryptography? What is B92? What is BB84? quantum key distribution quantum cryptography photon counting detectors photon–counting detectors time correlated single photon counting time–correlated single–photon counting SPAD single photon avalanche diode time resolved photon counting time resolved photoluminesence time resolved photo–luminesence time–resolved photoluminesence InGaAs/InP SPAD InGaAs/InP single photon avalanche diode Si SPAD Si single photon avalanche diode SiGe SPAD single photon avalanche diode InGaAs Indium–Galium–Arsenide/Indium–Phosphide SPAD Silicon SPAD Silicon–Germanium SPAD quantum communication quantum information processing Heriot Watt University Heriot–Watt University Indium cell In cell G.S. Buller Karen Veronica Sara Ross Robert Ryan B92 BB84 S. Cova S.D. Cova P. Townsend P.D. Townsend time of flight time–of–flight PhD lecturer postgraduate research associate Where is Heriot–Watt? Where is Heriot Watt? Edinburgh Scotland UK QUICK EQUIS SECOQC