Presentation 2020-05-20
[Invited Talk] How to Construct CSIDH on Edwards Curves (from CT-RSA 2020)
Tomoki Moriya, Hiroshi Onuki, Tsuyoshi Takagi,
PDF Download Page PDF download Page Link
Abstract(in Japanese) (See Japanese page)
Abstract(in English) CSIDH is an isogeny-based key-exchange protocol, that is one of the candidates for post-quantum cryptography. It is based on an ideal class group action on $mathbb{F}_p$-isomorphism classes of supersingular elliptic curves. In order to calculate the class group action, we need to take points defined over $mathbb{F}_{p^2}$. The original CSIDH algorithm only requires a calculation over $mathbb{F}_p$ by using Montgomery curves. If we try to do a similar calculation by using a $w$-coordinate on Edwards curves, we have to consider points defined over $mathbb{F}_{p^4}$. Therefore, it is not a trivial task to calculate the class group action on Edwards curves. In this presentation, I propose a new method to construct CSIDH by using the $w$-coordinate on Edwards curves, and give the computational complexity of this new algorithm.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) Isogeny-based cryptography / Montgomery curves / Edwards curves / CSIDH / Post-quantum cryptography
Paper # ISEC2020-8
Date of Issue 2020-05-13 (ISEC)

Conference Information
Committee ISEC
Conference Date 2020/5/20(1days)
Place (in Japanese) (See Japanese page)
Place (in English) Online
Topics (in Japanese) (See Japanese page)
Topics (in English)
Chair Shiho Moriai(NICT)
Vice Chair Shoichi Hirose(Univ. of Fukui) / Tetsuya Izu(Fujitsu Labs.)
Secretary Shoichi Hirose(NICT) / Tetsuya Izu(Tsukuba Univ.)
Assistant Dai Yamamoto(Fujitsu Labs.) / Yuuji Suga(IIJ)

Paper Information
Registration To Technical Committee on Information Security
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) [Invited Talk] How to Construct CSIDH on Edwards Curves (from CT-RSA 2020)
Sub Title (in English)
Keyword(1) Isogeny-based cryptography
Keyword(2) Montgomery curves
Keyword(3) Edwards curves
Keyword(4) CSIDH
Keyword(5) Post-quantum cryptography
1st Author's Name Tomoki Moriya
1st Author's Affiliation The University of Tokyo(UTokyo)
2nd Author's Name Hiroshi Onuki
2nd Author's Affiliation The University of Tokyo(UTokyo)
3rd Author's Name Tsuyoshi Takagi
3rd Author's Affiliation The University of Tokyo(UTokyo)
Date 2020-05-20
Paper # ISEC2020-8
Volume (vol) vol.120
Number (no) ISEC-28
Page pp.pp.31-31(ISEC),
#Pages 1
Date of Issue 2020-05-13 (ISEC)