Abstract
The k-SIDH protocol is a static-static isogeny-based key agreement protocol. At Mathcrypt 2018, Jao and Urbanik introduced a variant of this protocol which uses non-scalar automorphisms of special elliptic curves to improve its efficiency.
In this paper, we provide a new adaptive attack on Jao-Urbanik's protocol. The attack is a non-trivial adaptation of Galbraith-Petit-Shani-Ti's attack on SIDH (Asiacrypt 2016) and its extension to k-SIDH by Dobson-Galbraith-LeGrow-Ti-Zobernig (IACR eprint 2019).
Our attack provides a speedup compared to a naive application of Dobson et al's attack to Jao-Urbanik's scheme, exploiting its inherent structure. Estimating the security of k-SIDH and Jao-Urbanik's variant with respect to these attacks, k-SIDH provides better efficiency.
In this paper, we provide a new adaptive attack on Jao-Urbanik's protocol. The attack is a non-trivial adaptation of Galbraith-Petit-Shani-Ti's attack on SIDH (Asiacrypt 2016) and its extension to k-SIDH by Dobson-Galbraith-LeGrow-Ti-Zobernig (IACR eprint 2019).
Our attack provides a speedup compared to a naive application of Dobson et al's attack to Jao-Urbanik's scheme, exploiting its inherent structure. Estimating the security of k-SIDH and Jao-Urbanik's variant with respect to these attacks, k-SIDH provides better efficiency.
Original language | English |
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Title of host publication | Progress in Cryptology - AFRICACRYPT 2020 |
Subtitle of host publication | 12th International Conference on Cryptology in Africa, Cairo, Egypt, July 20 – 22, 2020, Proceedings |
Editors | Abderrahmane Nitaj, Amr Youssef |
Publisher | Springer |
Pages | 195-213 |
Number of pages | 19 |
Edition | 1 |
ISBN (Electronic) | 9783030519384 |
ISBN (Print) | 9783030519377 |
DOIs | |
Publication status | Published - 5 Jul 2020 |
Event | 12th International Conference on the Theory and Application of Cryptographic Techniques in Africa, AFRICACRYPT 2020 - Cairo, Egypt Duration: 20 Jul 2020 → 22 Jul 2020 |
Publication series
Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 12174 LNCS |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | 12th International Conference on the Theory and Application of Cryptographic Techniques in Africa, AFRICACRYPT 2020 |
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Country/Territory | Egypt |
City | Cairo |
Period | 20/07/20 → 22/07/20 |
Bibliographical note
Funding Information:We would like to thank David Jao and David Urbanik for their valuable comments and feedback on this work. Furthermore, we are grateful to Samuel Dobson, Steven D. Galbraith, Jason LeGrow, Yan Bo Ti, and Lukas Zobernig for their helpful clarifications regarding the DGLTZ attack. Work by the second and fourth authors was supported by an EPSRC New Investigator grant (EP/S01361X/1).
Publisher Copyright:
© Springer Nature Switzerland AG 2020.
Keywords
- Elliptic curves
- Isogenies
- k-SIDH
- Adaptive attack
ASJC Scopus subject areas
- Theoretical Computer Science
- Computer Science(all)