TY - GEN
T1 - Cryptanalysis of GiophantusTM Schemes against Hybrid Attack
AU - Wang, Yuntao
AU - Ikematsu, Yasuhiko
AU - Akiyama, Koichiro
AU - Takagi, Tsuyoshi
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Number 19F19378, 19K20266, JST CREST Grant Number JPMJCR14D6, Japan.
Publisher Copyright:
© 2020 ACM.
PY - 2020/10/5
Y1 - 2020/10/5
N2 - The hybrid attack was proposed by Howgrave-Graham in CRYPTO2007, which was originally designed for the cryptanalysis of NTRU cryptosystems. In this paper, based on Howgrave-Graham's attack model, we propose a simulator of hybrid attack to evaluate the hardness of the unique shortest vector problem. By a dynamical computation, our algorithm can trade off the cost between reduction and MitM, while both of them run in exponential time. Further, we adapt our simulator to Giophantus™, Giophantus+ and Giophantus-cryptosystems, proposed by Akiyama et al. in SAC2017, SCIS2019 and SCIS2020, respectively. Our analysis shows that by the hybrid attack, the security levels can be reduced by at most 19 bits for Giophantus' parameters proposed in NIST Post Quantum Cryptography (PQC) standardization 1st round submission. Meanwhile, the parameter sets of Giophantus+ and Giophantus-are secure against the hybrid attack.
AB - The hybrid attack was proposed by Howgrave-Graham in CRYPTO2007, which was originally designed for the cryptanalysis of NTRU cryptosystems. In this paper, based on Howgrave-Graham's attack model, we propose a simulator of hybrid attack to evaluate the hardness of the unique shortest vector problem. By a dynamical computation, our algorithm can trade off the cost between reduction and MitM, while both of them run in exponential time. Further, we adapt our simulator to Giophantus™, Giophantus+ and Giophantus-cryptosystems, proposed by Akiyama et al. in SAC2017, SCIS2019 and SCIS2020, respectively. Our analysis shows that by the hybrid attack, the security levels can be reduced by at most 19 bits for Giophantus' parameters proposed in NIST Post Quantum Cryptography (PQC) standardization 1st round submission. Meanwhile, the parameter sets of Giophantus+ and Giophantus-are secure against the hybrid attack.
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U2 - 10.1145/3384940.3388958
DO - 10.1145/3384940.3388958
M3 - Conference contribution
AN - SCOPUS:85095602443
T3 - APKC 2020 - Proceedings of the 7th ACM Workshop on ASIA Public-Key Cryptography, Co-located with AsiaCCS 2020
SP - 28
EP - 35
BT - APKC 2020 - Proceedings of the 7th ACM Workshop on ASIA Public-Key Cryptography, Co-located with AsiaCCS 2020
PB - Association for Computing Machinery, Inc
T2 - 7th ACM Workshop on Asia Public-Key Cryptography, APKC 2020, held in conjunction with the 15th ACM ASIA Conference on Computer and Communications Security, ACM ASIACCS 2020
Y2 - 6 October 2020
ER -