On the Security of Time-Lock Puzzles and Timed Commitments
On the Security of Time-Lock Puzzles and Timed Commitments
复制标题
论时间锁难题和限时承诺的安全性
DOI:
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发表时间:
2020
期刊:
影响因子:
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通讯作者:
Jiayu Xu
中科院分区:
文献类型:
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作者:
Jonathan Katz;J. Loss;Jiayu Xu
. Time-lock puzzles—problems whose solution requires some amount of sequential effort—have recently received increased interest (e.g., in the context of verifiable delay functions). Most constructions rely on the sequential-squaring conjecture that computing g 2 T mod N for a uniform g requires at least T (sequential) steps. We study the security of time-lock primitives from two perspectives: 1. We give the first hardness result about the sequential-squaring conjecture in a non-generic model of computation. Namely, in a quantitative version of the algebraic group model (AGM) that we call the strong AGM, we show that any speed up of sequential squaring is as hard as factoring N . 2. We then focus on timed commitments , one of the most important primitives that can be obtained from time-lock puzzles. We extend existing security definitions to settings that may arise when using timed commitments in higher-level protocols, and give the first construction of non-malleable timed commitments. As a building block of independent interest, we also define (and give constructions for) a related primitive called timed public-key encryption .
DOI:
10.1007/978-3-030-90456-2_15
发表时间:
2021
期刊:
TCC'21
影响因子:
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作者:
Cody Freitag;Ilan Komargodski;Rafael Pass;Naomi Sirkin
通讯作者:
Naomi Sirkin
DOI:
10.1007/978-3-030-26948-7_22
发表时间:
2019
期刊:
影响因子:
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作者:
Giulio Malavolta;Sri Aravinda Krishnan Thyagarajan
通讯作者:
Sri Aravinda Krishnan Thyagarajan