Paper 2023/1528

Unmodified Half-Gates is Adaptively Secure - So is Unmodified Three-Halves

Xiaojie Guo, State Key Laboratory of Cryptology, Nankai University
Kang Yang, State Key Laboratory of Cryptology
Xiao Wang, Northwestern University
Yu Yu, Shanghai Jiao Tong University, Shanghai Qi Zhi Institute
Zheli Liu, Nankai University
Abstract

Adaptive security is a crucial property for garbling schemes in pushing the communication of garbled circuits to an offline phase when the input is unknown. In this paper, we show that the popular half-gates scheme by Zahur et al. (Eurocrypt'15), without any modification, is adaptively secure in the non-programmable random permutation model (npRPM). Since real implementations of selective-secure half-gates are already based on npRPM, our result shows that these implementations are already adaptively secure under the same condition where selective security is proven. Additionally, we expand our analysis to cover the recent three-halves construction by Rosulek and Roy (Crypto'21). As a byproduct, we discuss some optimizations and separation when considering the programmable random permutation model instead.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
Keywords
Garbled CircuitAdaptive SecurityIdeal Models
Contact author(s)
xiaojie guo @ mail nankai edu cn
yangk @ sklc org
wangxiao @ northwestern edu
yuyu @ yuyu hk
liuzheli @ nankai edu cn
History
2024-01-16: last of 2 revisions
2023-10-06: received
See all versions
Short URL
https://ia.cr/2023/1528
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2023/1528,
      author = {Xiaojie Guo and Kang Yang and Xiao Wang and Yu Yu and Zheli Liu},
      title = {Unmodified Half-Gates is Adaptively Secure - So is Unmodified Three-Halves},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/1528},
      year = {2023},
      url = {https://eprint.iacr.org/2023/1528}
}
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