Imperfect 1-Out-of-2 Quantum Oblivious Transfer: Bounds, a Protocol, and its Experimental Implementation

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F21%3A73607440" target="_blank" >RIV/61989592:15310/21:73607440 - isvavai.cz</a>

Result on the web

<a href="https://journals.aps.org/prxquantum/pdf/10.1103/PRXQuantum.2.010335" target="_blank" >https://journals.aps.org/prxquantum/pdf/10.1103/PRXQuantum.2.010335</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PRXQuantum.2.010335" target="_blank" >10.1103/PRXQuantum.2.010335</a>

Result language

angličtina

Original language name

Imperfect 1-Out-of-2 Quantum Oblivious Transfer: Bounds, a Protocol, and its Experimental Implementation

Original language description

Oblivious transfer is an important primitive in modern cryptography. Applications include secure multiparty computation, oblivious sampling, e-voting, and signatures. Information-theoretically secure perfect 1-out-of 2 oblivious transfer is impossible to achieve. Imperfect variants, where both participants&apos; ability to cheat is still limited, are possible using quantum means while remaining classically impossible. Precisely what security parameters are attainable remains unknown. We introduce a theoretical framework for studying semirandom quantum oblivious transfer, which is shown to be equivalent to regular oblivious transfer in terms of cheating probabilities. We then use it to derive bounds on cheating. We also present a protocol with lower cheating probabilities than previous schemes, together with its optical realization. We show that a lower bound of 2/3 on the minimum achievable cheating probability can be directly derived for semirandom protocols using a different method and definition of cheating than used previously. The lower bound increases from 2/3 to approximately 0.749 if the states output by the protocol are pure and symmetric. The oblivious transfer scheme we present uses unambiguous state elimination measurements and can be implemented with the same technological requirements as standard quantum cryptography. In particular, it does not require honest participants to prepare or measure entangled states. The cheating probabilities are 3/4 and approximately 0.729 for sender and receiver, respectively, which is lower than in existing protocols. Using a photonic testbed, we have implemented the protocol with honest parties, as well as optimal cheating strategies. Because of the asymmetry of the receiver&apos;s and sender&apos;s cheating probabilities, the protocol can be combined with a &quot;trivial&quot; protocol to achieve an overall protocol with lower average cheating probabilities of approximately 0.74 for both sender and receiver. This demonstrates that, interestingly, protocols where the final output states are pure and symmetric are not optimal in terms of average cheating probability.

Czech name

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Czech description

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Type

J_ost - Miscellaneous article in a specialist periodical

CEP classification

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OECD FORD branch

10306 - Optics (including laser optics and quantum optics)

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

PRX Quantum

ISSN

2691-3399

e-ISSN

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Volume of the periodical

2

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

21

Pages from-to

"010335-1"-"010335-21"

UT code for WoS article

000674691500002

EID of the result in the Scopus database

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