IEICE TRANSACTIONS on Fundamentals
Tight Security of Twin-DH Hashed ElGamal KEM in Multi-User Setting
Summary :
It is an important research area to construct a cryptosystem that satisfies the security for multi-user setting. In addition, it is desirable that such a cryptosystem is tightly secure and the ciphertext size is small. For IND-CCA public key encryption schemes for multi-user setting with constant-size ciphertexts tightly secure under the DH assumptions, in 2020, Y. Sakai and G. Hanaoka firstly proposed such a scheme (implicitly based on hybrid encryption paradigm) under the DDH assumption. More recently, Y. Lee et al. proposed such a hybrid encryption scheme (with slightly stronger security) where the assumption for the KEM part is weakened to the CDH assumption. In this paper, we revisit the twin-DH hashed ElGamal KEM with even shorter ciphertexts than those schemes, and prove that its IND-CCA security for multi-user setting is in fact tightly reducible to the CDH assumption.
- Publication
- IEICE TRANSACTIONS on Fundamentals Vol.E105-A No.3 pp.173-181
- Publication Date
- 2022/03/01
- Publicized
- 2021/08/30
- Online ISSN
- 1745-1337
- DOI
- 10.1587/transfun.2021CIP0008
- Type of Manuscript
- Special Section PAPER (Special Section on Cryptography and Information Security)
- Category
Authors
Yuji HASHIMOTO
The University of Tokyo,the National Institute of Advanced Industrial Science and Technology
Koji NUIDA
The University of Tokyo,the National Institute of Advanced Industrial Science and Technology
Goichiro HANAOKA
the National Institute of Advanced Industrial Science and Technology
Keyword
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Yuji HASHIMOTO, Koji NUIDA, Goichiro HANAOKA, "Tight Security of Twin-DH Hashed ElGamal KEM in Multi-User Setting" in IEICE TRANSACTIONS on Fundamentals,
vol. E105-A, no. 3, pp. 173-181, March 2022, doi: 10.1587/transfun.2021CIP0008.
Abstract: It is an important research area to construct a cryptosystem that satisfies the security for multi-user setting. In addition, it is desirable that such a cryptosystem is tightly secure and the ciphertext size is small. For IND-CCA public key encryption schemes for multi-user setting with constant-size ciphertexts tightly secure under the DH assumptions, in 2020, Y. Sakai and G. Hanaoka firstly proposed such a scheme (implicitly based on hybrid encryption paradigm) under the DDH assumption. More recently, Y. Lee et al. proposed such a hybrid encryption scheme (with slightly stronger security) where the assumption for the KEM part is weakened to the CDH assumption. In this paper, we revisit the twin-DH hashed ElGamal KEM with even shorter ciphertexts than those schemes, and prove that its IND-CCA security for multi-user setting is in fact tightly reducible to the CDH assumption.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/transfun.2021CIP0008/_p
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@ARTICLE{e105-a_3_173,
author={Yuji HASHIMOTO, Koji NUIDA, Goichiro HANAOKA, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={Tight Security of Twin-DH Hashed ElGamal KEM in Multi-User Setting},
year={2022},
volume={E105-A},
number={3},
pages={173-181},
abstract={It is an important research area to construct a cryptosystem that satisfies the security for multi-user setting. In addition, it is desirable that such a cryptosystem is tightly secure and the ciphertext size is small. For IND-CCA public key encryption schemes for multi-user setting with constant-size ciphertexts tightly secure under the DH assumptions, in 2020, Y. Sakai and G. Hanaoka firstly proposed such a scheme (implicitly based on hybrid encryption paradigm) under the DDH assumption. More recently, Y. Lee et al. proposed such a hybrid encryption scheme (with slightly stronger security) where the assumption for the KEM part is weakened to the CDH assumption. In this paper, we revisit the twin-DH hashed ElGamal KEM with even shorter ciphertexts than those schemes, and prove that its IND-CCA security for multi-user setting is in fact tightly reducible to the CDH assumption.},
keywords={},
doi={10.1587/transfun.2021CIP0008},
ISSN={1745-1337},
month={March},}
Copy
TY - JOUR
TI - Tight Security of Twin-DH Hashed ElGamal KEM in Multi-User Setting
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 173
EP - 181
AU - Yuji HASHIMOTO
AU - Koji NUIDA
AU - Goichiro HANAOKA
PY - 2022
DO - 10.1587/transfun.2021CIP0008
JO - IEICE TRANSACTIONS on Fundamentals
SN - 1745-1337
VL - E105-A
IS - 3
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - March 2022
AB - It is an important research area to construct a cryptosystem that satisfies the security for multi-user setting. In addition, it is desirable that such a cryptosystem is tightly secure and the ciphertext size is small. For IND-CCA public key encryption schemes for multi-user setting with constant-size ciphertexts tightly secure under the DH assumptions, in 2020, Y. Sakai and G. Hanaoka firstly proposed such a scheme (implicitly based on hybrid encryption paradigm) under the DDH assumption. More recently, Y. Lee et al. proposed such a hybrid encryption scheme (with slightly stronger security) where the assumption for the KEM part is weakened to the CDH assumption. In this paper, we revisit the twin-DH hashed ElGamal KEM with even shorter ciphertexts than those schemes, and prove that its IND-CCA security for multi-user setting is in fact tightly reducible to the CDH assumption.
ER -
English
