IMO one of the effective potential of a QC is `Secure Encrypted communications`. There is a research project named QUESS (https://en.wikipedia.org/wiki/Quantum_Experiments_at_Space_S...).

This project involves a minisatellite (capable of generating entangled photons in space) to establish a space platform with long-distance satellite and ground quantum channel, and to carry out a series of tests about fundamental quantum principles and protocols in space-based large scale