7. Technical challenges

The scale of the challenges involved in developing quantum networks requires long-term plans and well-defined objectives, with reasonable milestones, while taking into account the global competition that has emerged in this field, as well as opportunities for international collaboration. The technical challenges for quantum satellite communications – with on-board quantum sources – are classified into two main categories, based on the time horizon and the targeted applications.

• Short-term challenges

  Focus on the initial use of satellites for quantum key distribution (QKD) services via polarization-based prepared-measured protocols or protocols based on entangled photon pairs. These challenges are more immediate because they aim to establish secure point-to-point links.

  These challenges include,...