A short impossibility proof of quantum bit commitment

作者：Chiribella Giulio^*; D' Ariano Giacomo Mauro; Perinotti Paolo; Schlingemann Dirk; Werner Reinhard

来源：Physics Letters A, 2013, 377(15): 1076-1087.

DOI：10.1016/j.physleta.2013.02.045

• Quantum protocols
• Quantum combs
• Quantum bit commitment

Bit commitment protocols, whose security is based on the laws of quantum mechanics alone, are generally held to be impossible on the basis of a concealment-bindingness tradeoff (Lo and Chau, 1997 [1], Mayers, 1997 [2]). A strengthened and explicit impossibility proof has been given in D%26apos;Ariano et al. (2007) [3] in the Heisenberg picture and in a C*-algebraic framework, considering all conceivable protocols in which both classical and quantum information is exchanged. In the present Letter we provide a new impossibility proof in the Schrodinger picture, greatly simplifying the classification of protocols and strategies using the mathematical formulation in terms of quantum combs (Chiribella et al., 2008 [4]), with each single-party strategy represented by a conditioned comb. We prove that assuming a stronger notion of concealment-for each classical communication history, not in average-allows Alice%26apos;s cheat to pass also the worst-case Bob%26apos;s test. The present approach allows us to restate the concealment-bindingness tradeoff in terms of the continuity of dilations of probabilistic quantum combs with the metric given by the comb discriminability-distance.

• 出版日期2013-6-17
• 单位清华大学