Experimental Guesswork with Quantum Side Information using Twisted Light

TL;DR

This paper extends the theoretical framework of guesswork with quantum side information to higher dimensions and demonstrates its experimental measurement using twisted light modes, confirming the theory's predictions.

Contribution

It provides the first experimental realization of guesswork with quantum side information in higher-dimensional optical systems, validating the theoretical models.

Findings

Experimental results closely match theoretical predictions.

Guesswork is a viable security criterion in quantum cryptography.

Higher-dimensional optical states can be used to compute guesswork experimentally.

Abstract

The guesswork is an information-theoretic quantity which can be seen as an alternate security criterion to entropy. Recent work has established the theoretical framework for guesswork in the presence of quantum side information, which we extend both theoretically and experimentally. We consider guesswork when the side information consists of the BB84 states and their higher-dimensional generalizations. With this side information, we compute the guesswork for two different scenarios for each dimension. We then perform a proof-of-principle experiment using Laguerre-Gauss modes to experimentally compute the guesswork for higher-dimensional generalizations of the BB84 states. We find that our experimental results agree closely with our theoretical predictions. This work shows that guesswork can be a viable security criterion in cryptographic tasks, and is experimentally accessible across a number of optical setups.