2013/06/25 by Yang Liu, Yuan Cao, Marcos Curty +19 · 1 citation
Computer Science · Physics and Astronomy · #Bit (key) #Causality (physics) #Cheating #Commitment scheme #Computer science #Computer security #Cryptography #Physics #Protocol (science) #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum cryptography #Quantum entanglement #Quantum information #Quantum information science #Quantum key distribution #Quantum mechanics #Theoretical computer science #Theoretical physics #Theory of relativity #quant-ph
paper · pdf · doi:10.1103/physrevlett.112.010504
published as Phys. Rev. Lett. 112, 010504 (2014) · 15 pages, 2 figures
arxiv created 2013/06/25 · openalex publication_date 2014/01/10 · arxiv updated 2015/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Quantum physics allows for unconditionally secure communication between parties that trust each other. However, when the parties do not trust each other such as in the bit commitment scenario, quantum physics is not enough to guarantee security unless extra assumptions are made. Unconditionally secure bit commitment only becomes feasible when quantum physics is combined with relativistic causality constraints. Here we experimentally implement a quantum bit commitment protocol with relativistic constraints that offers unconditional security. The commitment is made through quantum measurements in two quantum key distribution systems in which the results are transmitted via free-space optical communication to two agents separated with more than 20 km. The security of the protocol relies on the properties of quantum information and relativity theory. In each run of the experiment, a bit is successfully committed with less than 5.68×10(-2) cheating probability. This demonstrates the experimental feasibility of quantum communication with relativistic constraints.