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A Quantum Money Solution to the Blockchain Scalability Problem

Coladangelo, Andrea and Sattath, Or (2020) A Quantum Money Solution to the Blockchain Scalability Problem. Quantum, 4 . Art. No. 297. ISSN 2521-327X.

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We put forward the idea that classical blockchains and smart contracts are potentially useful primitives not only for classical cryptography, but for quantum cryptography as well. Abstractly, a smart contract is a functionality that allows parties to deposit funds, and release them upon fulfillment of algorithmically checkable conditions, and can thus be employed as a formal tool to enforce monetary incentives. In this work, we give the first example of the use of smart contracts in a quantum setting. We describe a simple hybrid classical-quantum payment system whose main ingredients are a classical blockchain capable of handling stateful smart contracts, and quantum lightning, a strengthening of public-key quantum money introduced by Zhandry [55]. Our hybrid payment system employs quantum states as banknotes and a classical blockchain to settle disputes and to keep track of the valid serial numbers. It has several desirable properties: it is decentralized, requiring no trust in any single entity; payments are as quick as quantum communication, regardless of the total number of users; when a quantum banknote is damaged or lost, the rightful owner can recover the lost value.

Item Type:Article
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URLURL TypeDescription Paper
Coladangelo, Andrea0000-0002-6773-2711
Sattath, Or0000-0001-7567-3822
Additional Information:This Paper is published in Quantum under the Creative Commons Attribution 4.0 International (CC BY 4.0) license. Copyright remains with the original copyright holders such as the authors or their institutions. Published: 2020-07-16. A.C is supported by the Simons Institute for the Theory of Computing. O.S. is supported by the Israel Science Foundation (ISF) grant No. 682/18 and 2137/19, and by the the Cyber Security Research Center at Ben-Gurion University.
Funding AgencyGrant Number
Simons Institute for the Theory of ComputingUNSPECIFIED
Israel Science Foundation682/18
Israel Science Foundation2137/19
Ben-Gurion UniversityUNSPECIFIED
Record Number:CaltechAUTHORS:20200806-102928042
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104773
Deposited By: Tony Diaz
Deposited On:06 Aug 2020 18:06
Last Modified:06 Aug 2020 18:06

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