Efficient Regular Modular Exponentiation Using Multiplicative Half-Size Splitting

Christophe Negre 1 Thomas Plantard 2
1 DALI - Digits, Architectures et Logiciels Informatiques
LIRMM - Laboratoire d'Informatique de Robotique et de Microélectronique de Montpellier, UPVD - Université de Perpignan Via Domitia
Abstract : In this paper, we consider efficient RSA modular exponentiations x^K \mod N which are regular and constant time. We first review the multiplicative splitting of an integer x modulo N into two half-size integers. We then take advantage of this splitting to modify the square-and-multiply exponentiation as a regular sequence of squarings always followed by a multiplication by a half-size integer. The proposed method requires around 16% less word operations compared to Montgomery-ladder, square-always and square-and-multiply-always exponentiations. These theoretical results are validated by our implementation results which show an improvement by more than 12% compared approaches which are both regular and constant time.
Document type :
Journal articles
Liste complète des métadonnées

Cited literature [19 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-01185249
Contributor : Christophe Negre <>
Submitted on : Friday, August 21, 2015 - 8:39:24 AM
Last modification on : Saturday, February 16, 2019 - 9:34:27 AM
Document(s) archivé(s) le : Wednesday, April 26, 2017 - 9:43:59 AM

File

regular-expo-with-half-size-mu...
Files produced by the author(s)

Licence


Distributed under a Creative Commons Attribution 4.0 International License

Identifiers

Collections

Citation

Christophe Negre, Thomas Plantard. Efficient Regular Modular Exponentiation Using Multiplicative Half-Size Splitting. Journal of Cryptographic Engineering, Springer, 2017, 7 (3), pp.245-253. ⟨10.1007/s13389-016-0134-5⟩. ⟨hal-01185249⟩

Share

Metrics

Record views

305

Files downloads

478