Flexible quantum tokens in spacetime

Abstract

S-money [Proc. R. Soc. A 475, 20190170 (2019)] schemes define virtual tokens designed for networks with relativistic or other trusted signalling constraints. The tokens allow near-instant verification and guarantee unforgeability without requiring quantum state storage. We present refined two stage S-money schemes. The first stage, which may involve quantum information exchange, generates private user token data. In the second stage, which need only involve classical communications, users determine the valid presentation point, without revealing it to the issuer. This refinement allows the user to determine the presentation point anywhere in the causal past of all valid presentation points. It also allows flexible transfer of tokens among users without compromising user privacy.

arXiv commentAccepted manuscript. To appear in Physical Review A

References in corpus (8)

• Unconditionally Secure Bit Commitment by Transmitting Measurement Outcomes
• Experimental bit commitment based on quantum communication and special relativity
• Unforgeable Noise-Tolerant Quantum Tokens
• Secure bit commitment from relativistic constraints
• Security Details for Bit Commitment by Transmitting Measurement Outcomes
• Practical and unconditionally secure spacetime-constrained oblivious transfer
• One-out-of-$m$ spacetime-constrained oblivious transfer
• S-money: virtual tokens for a relativistic economy

Cited by in corpus (5)

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• Quantum cryptography beyond key distribution: theory and experiment
• Practical quantum tokens without quantum memories and experimental tests
• Cryptanalysis and improvement of Wu-Cai-Wu-Zhang's quantum private comparison protocol