Demonstration of quantum-digital payments

Peter Schiansky, Julia Kalb, Esther Sztatecsny, Marie Christine Roehsner, Tobias Guggemos, Alessandro Trenti, Mathieu Bozzio (Corresponding author), Philip Walther (Corresponding author)

Publications: Contribution to journalArticlePeer Reviewed


Digital payments have replaced physical banknotes in many aspects of our daily lives. Similarly to banknotes, they should be easy to use, unique, tamper-resistant and untraceable, but additionally withstand digital attackers and data breaches. Current technology substitutes customers’ sensitive data by randomized tokens, and secures the payment’s uniqueness with a cryptographic function, called a cryptogram. However, computationally powerful attacks violate the security of these functions. Quantum technology comes with the potential to protect even against infinite computational power. Here, we show how quantum light can secure daily digital payments by generating inherently unforgeable quantum cryptograms. We implement the scheme over an urban optical fiber link, and show its robustness to noise and loss-dependent attacks. Unlike previously proposed protocols, our solution does not depend on long-term quantum storage or trusted agents and authenticated channels. It is practical with near-term technology and may herald an era of quantum-enabled security.
Original languageEnglish
Article number3849
Number of pages7
JournalNature Communications
Issue number1
Publication statusPublished - 29 Jun 2023

Austrian Fields of Science 2012

  • 103026 Quantum optics

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