Photonic quantum data locking

Quantum data locking is a quantum phenomenon that allows us to encrypt long message with small secret key information-theoretic security. This in sharp contrast classical information theory where, according Shannon, the needs be at least as message. Here we explore photonic architectures for locking, where encoded multi-photon states and processed using multi-mode linear optics photo-detection, goal of extending an initial into longer one. % The consumption depends on number modes photons employed. In no-collision limit, likelihood photon bunching suppressed, shown logarithmic dimensions system. Our protocol can viewed application physics Boson Sampling cryptography. Experimental realisations are challenging but feasible state-of-the-art technology, techniques recently used demonstrate adapted our scheme (e.g., Phys. Rev. Lett. 123, 250503, 2019).