English

Flexible quantum tokens in spacetime

Quantum Physics 2020-02-13 v2 Cryptography and Security

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.

Keywords

Cite

@article{arxiv.1908.08143,
  title  = {Flexible quantum tokens in spacetime},
  author = {Adrian Kent and Damián Pitalúa-García},
  journal= {arXiv preprint arXiv:1908.08143},
  year   = {2020}
}

Comments

Accepted manuscript. To appear in Physical Review A

R2 v1 2026-06-23T10:53:47.276Z