



01315nas a2200145   4500008004100000245004100041210004100082260001500123300001100138490000600149520091300155100001601068700001701084856006801101       2017                        eng d00aRigidity of the magic pentagram game0 aRigidity of the magic pentagram game  c2017/11/02  a0150020 v33 a<p><span style="font-family: &quot;Lucida Grande&quot;, helvetica, arial, verdana, sans-serif; font-size: 14.4px;">A game is rigid if a near-optimal score guarantees, under the sole assumption of the validity of quantum mechanics, that the players are using an approximately unique quantum strategy. Rigidity has a vital role in quantum cryptography as it permits a strictly classical user to trust behavior in the quantum realm. This property can be traced back as far as 1998 (Mayers and Yao) and has been proved for multiple classes of games. In this paper we prove ridigity for the magic pentagram game, a simple binary constraint satisfaction game involving two players, five clauses and ten variables. We show that all near-optimal strategies for the pentagram game are approximately equivalent to a unique strategy involving real Pauli measurements on three maximally-entangled qubit pairs.</span></p>1 aKalev, Amir1 aMiller, Carl  uhttp://iopscience.iop.org/article/10.1088/2058-9565/aa931d/meta