Current state-of-the-art in space-based quantum key distribution (QKD) is Trusted Node QKD from a low Earth orbit (LEO) satellite that creates keys between the satellite and ground station. To share symmetric encryption keys between two remote ground stations, the satellite can create separate keys at the two sites, then reconcile the keys between them. This implies that the satellite needs to know both keys, making it a trusted node. Ultimate security is achieved by simultaneously creating keys using two quantum channels from a satellite, known as double downlink QKD. This is the ultimate in security because the satellite does not need to be trusted. This system relies on distributing entanglement from a satellite with an advanced source of entangled photons that is compact and space qualified. SQT is the only company outside of China with this heritage. This project addresses the feasibility of a MEO satellite providing this service over the continental United States.
