By Zixin Huang, Peter P. Rohde, Dominic W. Berry, Pieter Kok, Jonathan P. Dowling & Cosmo Lupo.
Submitted to arXiv on 21 July 2020.
Quantum data locking is a quantum phenomenon that allows us to encrypt a long message with a small secret key with information-theoretic security. This is in sharp contrast with classical information theory where, according to Shannon, the secret key needs to be at least as long as the message. Here we explore photonic architectures for quantum data locking, where information is encoded in multi-photon states and processed using multi-mode linear optics and photo-detection. Experimental realisations are challenging but feasible with state-of-the-art technology. In particular, techniques recently used to demonstrate Boson Sampling can be adapted to our scheme.