See Physical Review Letters and the following releases for more details:
physik.univie.ac.at/news/news-detailansicht/news/quantenzertifikat-eine-kommunikationsaufgabe-zur-pruefung-der-nichtklassizitaet/ and
www.iqoqi-vienna.at/detail/news/quantum-certified-a-communication-task-to-test-non-classicality/