Continuous-variable quantum authentication of physical unclonable keys

We propose a scheme for authentication of physical keys that are materialized by optical multiple-scattering media. The authentication relies on the optical response of the key when probed by randomly selected coherent states of light, and the use of standard wavefront-shaping techniques that direct the scattered photons coherently to a specific target mode at the output. The quadratures of the electromagnetic field of the scattered light at the target mode are analysed using a homodyne detection scheme, and the acceptance or rejection of the key is decided upon the outcomes of the measurements. The proposed scheme can be implemented with current technology and offers collision resistance and robustness against key cloning.Comment: 15 pages, 7 figure

Effects of Kerr nonlinearity in physical unclonable functions

We address the question of whether the presence of Kerr nonlinearity in multiple-scattering optical media offers any advantage with respect to the design of physical unclonable functions. Our results suggest that under certain conditions, nonlinear physical unclonable functions can be more robust against the potential cloning of the medium, relative to their linear counterparts that have been exploited in the context of various cryptographic applications

Computational indistinguishability and boson sampling

We introduce a computational problem of distinguishing between the output of an ideal coarse-grained boson sampler and the output of a true random number generator, as a resource for cryptographic schemes, which are secure against computationally unbounded adversaries. Moreover, we define a cryptographic setting for the implementation of such schemes, including message encryption and authentication, as well as entity authentication