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Optimized Method for Computing Odd-Degree Isogenies on Edwards Curves

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Advances in Cryptology – ASIACRYPT 2019 (ASIACRYPT 2019)

Part of the book series: Lecture Notes in Computer Science ((LNSC,volume 11922))

Abstract

In this paper, we present an efficient method to compute arbitrary odd-degree isogenies on Edwards curves. By using the w-coordinate, we optimized the isogeny formula on Edwards curves by Moody and Shumow. We demonstrate that Edwards curves have an additional benefit when recovering the coefficient of the image curve during isogeny computation. For \(\ell \)-degree isogeny where \(\ell =2s+1\), our isogeny formula on Edwards curves outperforms Montgomery curves when \(s \ge 2\). To better represent the performance improvements when w-coordinate is used, we implement CSIDH using our isogeny formula. Our implementation is about 20% faster than the previous implementation. The result of our work opens the door for the usage of Edwards curves in isogeny-based cryptography, especially for CSIDH which requires higher degree isogenies.

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2017R1A2B4011599).

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References

  1. Azarderakhsh, R., Bakos Lang, E., Jao, D., Koziel, B.: EdSIDH: supersingular isogeny Diffie-Hellman key exchange on Edwards curves. In: Chattopadhyay, A., Rebeiro, C., Yarom, Y. (eds.) SPACE 2018. LNCS, vol. 11348, pp. 125–141. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-05072-6_8

    Chapter  Google Scholar 

  2. Azarderakhsh, R., et al.: Supersingular isogeny key encapsulation. Submission to the NIST Post-Quantum Standardization Project (2017)

    Google Scholar 

  3. 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

    Chapter  Google Scholar 

  4. Bernstein, D.J., Lange, T.: Inverted Edwards coordinates. In: Boztaş, S., Lu, H.-F.F. (eds.) AAECC 2007. LNCS, vol. 4851, pp. 20–27. Springer, Heidelberg (2007). https://doi.org/10.1007/978-3-540-77224-8_4

    Chapter  Google Scholar 

  5. Bos, J.W., Friedberger, S.J.: Arithmetic considerations for isogeny-based cryptography. IEEE Trans. Comput. 68(7), 979–990 (2019)

    Article  MathSciNet  Google Scholar 

  6. Bröker, R.: Constructing supersingular elliptic curves. J. Comb. Number Theory 1(3), 269–273 (2009)

    MathSciNet  MATH  Google Scholar 

  7. Mendel, F., Nad, T., Schläffer, M.: Finding SHA-2 characteristics: searching through a minefield of contradictions. In: Lee, D.H., Wang, X. (eds.) ASIACRYPT 2011. LNCS, vol. 7073, pp. 288–307. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-25385-0_16

    Chapter  Google Scholar 

  8. Childs, A., Jao, D., Soukharev, V.: Constructing elliptic curve isogenies in quantum subexponential time. J. Math. Cryptol. 8(1), 1–29 (2014)

    Article  MathSciNet  Google Scholar 

  9. 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

    Chapter  Google Scholar 

  10. Costello, C., Longa, P., Naehrig, M.: SIDH library (2016–2018). https://github.com/Microsoft/PQCrypto-SIDH

  11. 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

    Chapter  Google Scholar 

  12. Couveignes, J.M.: Hard homogeneous spaces (2006). https://eprint.iacr.org/2006/291

  13. De Feo, L., Kieffer, J., Smith, B.: Towards practical key exchange from ordinary isogeny graphs. In: Peyrin, T., Galbraith, S. (eds.) ASIACRYPT 2018. LNCS, vol. 11274, pp. 365–394. Springer, Cham (2018). https://doi.org/10.1007/978-3-030-03332-3_14

    Chapter  Google Scholar 

  14. Farashahi, R.R., Hosseini, S.G.: Differential addition on twisted Edwards curves. In: Pieprzyk, J., Suriadi, S. (eds.) ACISP 2017. LNCS, vol. 10343, pp. 366–378. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-59870-3_21

    Chapter  Google Scholar 

  15. Hisil, H., Wong, K.K.-H., Carter, G., Dawson, E.: Twisted Edwards curves revisited. In: Pieprzyk, J. (ed.) ASIACRYPT 2008. LNCS, vol. 5350, pp. 326–343. Springer, Heidelberg (2008). https://doi.org/10.1007/978-3-540-89255-7_20

    Chapter  Google Scholar 

  16. Jao, D., De Feo, L.: Towards quantum-resistant cryptosystems from supersingular elliptic curve isogenies. In: Yang, B.-Y. (ed.) PQCrypto 2011. LNCS, vol. 7071, pp. 19–34. Springer, Heidelberg (2011). https://doi.org/10.1007/978-3-642-25405-5_2

    Chapter  MATH  Google Scholar 

  17. Kim, S., Yoon, K., Kwon, J., Hong, S., Park, Y.H.: Efficient isogeny computations on twisted Edwards curves. Secur. Commun. Netw. 2018, 1–11 (2018)

    Google Scholar 

  18. Kim, S., Yoon, K., Kwon, J., Park, Y.H., Hong, S.: New hybrid method for isogeny-based cryptosystems using Edwards curves. IEEE Trans. Inf. Theory (2019). https://doi.org/10.1109/TIT.2019.2938984

  19. 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

    Chapter  Google Scholar 

  20. Meyer, M., Reith, S., Campos, F.: On hybrid SIDH schemes using Edwards and Montgomery curve arithmetic (2017). https://eprint.iacr.org/2017/1213

  21. Moody, D., Shumow, D.: Analogues of Vélu’s formulas for isogenies on alternate models of elliptic curves. Math. Comput. 85(300), 1929–1951 (2016)

    Article  Google Scholar 

  22. Moriya, T., Onuki, H., Takagi, T.: How to construct CSIDH on Edwards curves. Cryptology ePrint Archive, Report 2019/843 (2019). https://eprint.iacr.org/2019/843

  23. 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)

    Article  MathSciNet  Google Scholar 

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Acknowledgement

We thank the anonymous reviewers for their useful and constructive comments.

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Correspondence to Young-Ho Park .

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Kim, S., Yoon, K., Park, YH., Hong, S. (2019). Optimized Method for Computing Odd-Degree Isogenies on Edwards Curves. In: Galbraith, S., Moriai, S. (eds) Advances in Cryptology – ASIACRYPT 2019. ASIACRYPT 2019. Lecture Notes in Computer Science(), vol 11922. Springer, Cham. https://doi.org/10.1007/978-3-030-34621-8_10

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  • DOI: https://doi.org/10.1007/978-3-030-34621-8_10

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  • Online ISBN: 978-3-030-34621-8

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