TY - GEN
T1 - Group Key Exchange from CSIDH and Its Application to Trusted Setup in Supersingular Isogeny Cryptosystems
AU - Moriya, Tomoki
AU - Takashima, Katsuyuki
AU - Takagi, Tsuyoshi
N1 - Funding Information:
Acknowlegements. This work was supported by JST CREST Grant Number JPMJCR14D6, Japan.
Publisher Copyright:
© 2020, Springer Nature Switzerland AG.
PY - 2020
Y1 - 2020
N2 - In this paper, we propose a multi-party (group) key exchange protocol based on CSIDH (Commutative Supersingular Isogeny Diffie–Hellman), which is a post-quantum Diffie-Hellman type key exchange protocol from a commutative group action. The proposed group key exchange protocol called G-CSIDH uses the same size prime modulus p as that in CSIDH for the same security level, and the security of G-CSIDH is reduced to the security of CSIDH. In addition, we propose the trusted protocol of generating public parameters of supersingular isogeny cryptosystems by using the proposed G-CSIDH. Trust in the setup based on G-CSIDH is reduced to the security of G-CSIDH, and then that of CSIDH. The trusted protocol can be applied to any supersingular isogeny cryptosystem, which uses a supersingular elliptic curve as a public parameter.
AB - In this paper, we propose a multi-party (group) key exchange protocol based on CSIDH (Commutative Supersingular Isogeny Diffie–Hellman), which is a post-quantum Diffie-Hellman type key exchange protocol from a commutative group action. The proposed group key exchange protocol called G-CSIDH uses the same size prime modulus p as that in CSIDH for the same security level, and the security of G-CSIDH is reduced to the security of CSIDH. In addition, we propose the trusted protocol of generating public parameters of supersingular isogeny cryptosystems by using the proposed G-CSIDH. Trust in the setup based on G-CSIDH is reduced to the security of G-CSIDH, and then that of CSIDH. The trusted protocol can be applied to any supersingular isogeny cryptosystem, which uses a supersingular elliptic curve as a public parameter.
KW - CSIDH
KW - Group key exchange
KW - Isogeny-based cryptography
UR - http://www.scopus.com/inward/record.url?scp=85085258098&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85085258098&partnerID=8YFLogxK
U2 - 10.1007/978-3-030-42921-8_5
DO - 10.1007/978-3-030-42921-8_5
M3 - Conference contribution
AN - SCOPUS:85085258098
SN - 9783030429201
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 86
EP - 98
BT - Information Security and Cryptology - 15th International Conference, Inscrypt 2019, Revised Selected Papers
A2 - Liu, Zhe
A2 - Yung, Moti
PB - Springer
T2 - 15th International Conference on Information Security and Cryptology, Inscrypt 2019
Y2 - 6 December 2019 through 8 December 2019
ER -