Paper 2024/2078

Strongly Secure Universal Thresholdizer

Ehsan Ebrahimi, University of Luxembourg
Anshu Yadav, Institute of Science and Technology Austria
Abstract

A universal thresholdizer (UT), constructed from a threshold fully homomorphic encryption by Boneh et. al , Crypto 2018, is a general framework for universally thresholdizing many cryptographic schemes. However, their framework is insufficient to construct strongly secure threshold schemes, such as threshold signatures and threshold public-key encryption, etc. In this paper, we strengthen the security definition for a universal thresholdizer and propose a scheme which satisfies our stronger security notion. Our UT scheme is an improvement of Boneh et. al ’s construction at the level of threshold fully homomorphic encryption using a key homomorphic pseudorandom function. We apply our strongly secure UT scheme to construct strongly secure threshold signatures and threshold public-key encryption.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
A major revision of an IACR publication in ASIACRYPT 2024
Contact author(s)
ehsan ebrahimi @ uni lu
anshu yadav06 @ gmail com
History
2024-12-27: approved
2024-12-26: received
See all versions
Short URL
https://ia.cr/2024/2078
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2024/2078,
      author = {Ehsan Ebrahimi and Anshu Yadav},
      title = {Strongly Secure Universal Thresholdizer},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/2078},
      year = {2024},
      url = {https://eprint.iacr.org/2024/2078}
}
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