Abstract
Isogeny-based cryptography, such as commutative supersingular isogeny Diffie-Hellman (CSIDH), has been shown to be promising candidates for post-quantum cryptography. However, their speeds have remained unremarkable. For example, computing odd-degree isogenies between Montgomery curves is a dominant computation in CSIDH. To increase the speed of this isogeny computation, this study proposes a new technique called the “2-ADD-Skip method,” which reduces the required number of points to be computed. This technique is then used to develop a novel algorithm for isogeny computation. It is found that the proposed algorithm requires fewer field arithmetic operations for the degrees of \(\ell \ge 19\) compared with the algorithm of Meyer et al., which utilizes twisted Edwards curves. Further, a prototype CSIDH-512 implementation shows that the proposed algorithm can give a 6.7% speedup over the implementation by Meyer et al. Finally, individual experiments for each degree of isogeny show that the proposed algorithm requires the lowest number of clock cycles among existing algorithms for \(19 \le \ell \le 373\).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
De Feo, L., Jao, D., Plût, J.: Towards quantum-resistant cryptosystems from supersingular elliptic curve isogenies. J. Math. Cryptol. 8(3), 209–247 (2014)
Castryck, W., Lange, T., Martindale, C., Panny, L., Renes, J.: CSIDH: an efficient post-quantum commutative group action. In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018. LNCS, vol. 11274, pp. 395–427. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-03332-3_15
Jao, D., et al.: Supersingular isogeny key encapsulation. Submission to the NIST Post- Quantum Cryptography Standardization project. https://sike.org
Alagic, G., et al.: Status report on the first round of the NIST post-quantum cryptography standardization process. NISTIR 8240 (2019)
Meyer, M., Reith, S.: A faster way to the CSIDH. In: Chakraborty, D., Iwata, T. (eds.) INDOCRYPT 2018. LNCS, vol. 11356, pp. 137–152. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-05378-9_8
Meyer, M., Campos, F., Reith, S.: On lions and elligators: an efficient constant-time implementation of CSIDH. In: Ding, J., Steinwandt, R. (eds.) PQCrypto 2019. LNCS, vol. 11505, pp. 307–325. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-25510-7_17
Hutchinson, A., LeGrow, J.T., Koziel, B., Azarderakhsh, R.: Further optimizations of CSIDH: a systematic approach to efficient strategies, permutations, and bound vectors. IACR Cryptol. ePrint Arch. 2019, 1121 (2019)
Nakagawa, K., Onuki, H., Takayasu, A., Takagi, T.: \(L_1\)-norm ball for CSIDH: optimal strategy for choosing the secret key space. IACR Cryptol. ePrint Arch. 2020, 181 (2020)
Cervantes-Vázquez, D., Chenu, M., Chi-Domínguez, J.-J., De Feo, L., Rodríguez-Henríquez, F., Smith, B.: Stronger and faster side-channel protections for CSIDH. In: Schwabe, P., Thériault, N. (eds.) LATINCRYPT 2019. LNCS, vol. 11774, pp. 173–193. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-30530-7_9
Bernstein, D.J., Lange, T., Martindale, C., Panny, L.: Quantum circuits for the CSIDH: optimizing quantum evaluation of isogenies. In: Ishai, Y., Rijmen, V. (eds.) EUROCRYPT 2019. LNCS, vol. 11477, pp. 409–441. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-17656-3_15
Bernstein, D.J., De Feo, L., Leroux, A., Smith, B.: Faster computation of isogenies of large prime degree. IACR Cryptol. ePrint Arch. 2020, 341 (2020)
Onuki, H., Aikawa, Y., Yamazaki, T., Takagi, T.: (Short paper) a faster constant-time algorithm of CSIDH keeping two points. In: Attrapadung, N., Yagi, T. (eds.) IWSEC 2019. LNCS, vol. 11689, pp. 23–33. Springer, Cham (2019). https://doi.org/10.1007/978-3-030-26834-3_2
Costello, C., Hisil, H.: A simple and compact algorithm for SIDH with arbitrary degree isogenies. In: Takagi, T., Peyrin, T. (eds.) ASIACRYPT 2017. LNCS, vol. 10625, pp. 303–329. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-70697-9_11
Montgomery, P.L.: Speeding the Pollard and elliptic curve methods of factorization. Math. Comput. 48, 243–264 (1987)
Costello, C., Longa, P., Naehrig, M.: Efficient algorithms for supersingular isogeny Diffie-Hellman. In: Robshaw, M., Katz, J. (eds.) CRYPTO 2016. LNCS, vol. 9814, pp. 572–601. Springer, Heidelberg (2016). https://doi.org/10.1007/978-3-662-53018-4_21
Bernstein, D.J., Birkner, P., Joye, M., Lange, T., Peters, C.: Twisted Edwards curves. In: Vaudenay, S. (ed.) AFRICACRYPT 2008. LNCS, vol. 5023, pp. 389–405. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-68164-9_26
Castryck, W., Galbraith, S.D., Farashahi, R.R.: Efficient arithmetic on elliptic curves using a mixed Edwards-Montgomery representation. IACR Cryptol. ePrint Arch. 2008, 218 (2008)
Vélu, J.: Isogènies entre courbes elliptiques. C R Acad. Sci. Paris Sér. A-B 273, A238–A241 (1971)
Couveignes, J.M.: Hard homogeneous spaces. IACR Cryptol. ePrint Arch. 2006, 291 (2006)
Rostovtsev, A., Stolbunov, A.: Public-key cryptosystem based on isogenies. IACR Cryptol. ePrint Arch. 2006, 145 (2006)
Stolbunov, A.: Constructing public-key cryptographic schemes based on class group action on a set of isogenous elliptic curves. Adv. Math. Commun. 4(2), 215–235 (2010)
Renes, J.: Computing isogenies between montgomery curves using the action of (0, 0). In: Lange, T., Steinwandt, R. (eds.) PQCrypto 2018. LNCS, vol. 10786, pp. 229–247. Springer, Cham (2018). https://doi.org/10.1007/978-3-319-79063-3_11
Moody, D., Shumow, D.: Analogues of Vélu’s formulas for isogenies on alternate models of elliptic curves. Math. Comput. 85(300), 1929–1951 (2016)
Acknowledgments
This work was supported by JSPS KAKENHI Grant Number JP19J10400, enPiT (Education Network for Practical Information Technologies) at MEXT, and Innovation Platform for Society 5.0 at MEXT.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Switzerland AG
About this paper
Cite this paper
Kodera, K., Cheng, CM., Miyaji, A. (2020). Efficient Algorithm for Computing Odd-Degree Isogenies on Montgomery Curves. In: You, I. (eds) Information Security Applications. WISA 2020. Lecture Notes in Computer Science(), vol 12583. Springer, Cham. https://doi.org/10.1007/978-3-030-65299-9_20
Download citation
DOI: https://doi.org/10.1007/978-3-030-65299-9_20
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-65298-2
Online ISBN: 978-3-030-65299-9
eBook Packages: Computer ScienceComputer Science (R0)