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.
https://hal.archives-ouvertes.fr/hal-01185249
Contributeur : Christophe Negre
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Soumis le : vendredi 21 août 2015 - 08:39:24
Dernière modification le : jeudi 24 mai 2018 - 15:59:23
Document(s) archivé(s) le : mercredi 26 avril 2017 - 09:43:59
