Cryptology ePrint Archive: Report 2022/008
Beating Classical Impossibility of Position Verification
Jiahui Liu and Qipeng Liu and Luowen Qian
Abstract: Chandran et al. (SIAM J. Comput.'14) formally introduced the cryptographic task of position verification, where they also showed that it cannot be achieved by classical protocols. In this work, we initiate the study of position verification protocols with classical verifiers. We identify that proofs of quantumness (and thus computational assumptions) are necessary for such position verification protocols. For the other direction, we adapt the proof of quantumness protocol by Brakerski et al. (FOCS'18) to instantiate such a position verification protocol. As a result, we achieve classically verifiable position verification assuming the quantum hardness of Learning with Errors.
Along the way, we develop the notion of 1-of-2 non-local soundness for a natural non-local game for 1-of-2 puzzles, first introduced by Radian and Sattath (AFT'19), which can be viewed as a computational unclonability property. We show that 1-of-2 non-local soundness follows from the standard 2-of-2 soundness (and therefore the adaptive hardcore bit property), which
could be of independent interest.
Category / Keywords: cryptographic protocols / cryptographic protocol, position verification, quantum cryptography, proof of quantumness, non-locality
Original Publication (in the same form): ITCS 2022
Date: received 3 Jan 2022
Contact author: jiahui at cs utexas edu, qipengliu0 at gmail com, luowenq at bu edu
Available format(s): PDF | BibTeX Citation
Version: 20220107:165317 (All versions of this report)
Short URL: ia.cr/2022/008
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