International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

Shohei Egashira

Publications

Year
Venue
Title
2021
JOFC
Fine-Grained Cryptography Revisited
Shohei Egashira Yuyu Wang Keisuke Tanaka
Fine-grained cryptographic primitives are secure against adversaries with bounded resources and can be computed by honest users with less resources than the adversaries. In this paper, we revisit the results by Degwekar, Vaikuntanathan, and Vasudevan in Crypto 2016 on fine-grained cryptography and show constructions of three key fundamental fine-grained cryptographic primitives: one-way permutation families , hash proof systems (which in turn implies a public-key encryption scheme against chosen chiphertext attacks ), and trapdoor one-way functions . All of our constructions are computable in $$\textsf {NC}^1$$ NC 1 and secure against ( non-uniform ) $$\textsf {NC}^1$$ NC 1 circuits under the widely believed worst-case assumption $$\textsf {NC}^1\subsetneq {\oplus \textsf {L/poly}}$$ NC 1 ⊊ ⊕ L / poly .
2019
ASIACRYPT
Fine-Grained Cryptography Revisited
Shohei Egashira Yuyu Wang Keisuke Tanaka
Fine-grained cryptographic primitives are secure against adversaries with bounded resources and can be computed by honest users with less resources than the adversaries. In this paper, we revisit the results by Degwekar, Vaikuntanathan, and Vasudevan in Crypto 2016 on fine-grained cryptography and show the constructions of three key fundamental fine-grained cryptographic primitives: one-way permutations, hash proof systems (which in turn implies a public-key encryption scheme against chosen chiphertext attacks), and trapdoor one-way functions. All of our constructions are computable in $$\mathsf {NC^1}$$ and secure against (non-uniform) $$\mathsf {NC^1}$$ circuits under the widely believed worst-case assumption $$\mathsf {NC^1}\subsetneq \mathsf{\oplus L/poly}$$.

Coauthors

Keisuke Tanaka (2)
Yuyu Wang (2)