Guesswork of a quantum ensemble

Michele Dall'Arno, University of Kyoto and Waseda University, Japan

The guesswork of a quantum ensemble quantifies the minimum number of guesses needed in average to correctly guess an unknown message encoded in the states of the ensemble. Here, we derive sufficient conditions under which the computation of the minimum guesswork can be recast as a discrete problem. We show that such conditions are always satisfied for qubit ensembles with uniform probability distribution, thus settling the problem in that case. As applications, we compute the guesswork for any qubit regular-polygonal and regular-polyhedral ensembles. Based on arXiv:2012.09350.

Recording of the talk