Cryptology ePrint Archive: Report 2021/1314

High-order Table-based Conversion Algorithms and Masking Lattice-based Encryption

Jean-Sébastien Coron and François Gérard and Simon Montoya and Rina Zeitoun

Abstract: Masking is the main countermeasure against side-channel attacks on embedded devices. For cryptographic algorithms that combine Boolean and arithmetic masking, one must therefore convert between the two types of masking, without leaking additional information to the attacker. In this paper we describe a new high-order conversion algorithm between Boolean and arithmetic masking, based on table recomputation, and provably secure in the ISW probing model. We show that our technique is particularly efficient for masking structured LWE encryption schemes such as Kyber and Saber. In particular, for Kyber IND-CPA decryption, we obtain an order of magnitude improvement compared to existing techniques.

Category / Keywords: implementation / High-order masking, lattice-based cryptography, conversion algorithms

Date: received 29 Sep 2021, last revised 30 Sep 2021

Contact author: jscoron at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20210930:122031 (All versions of this report)

Short URL: ia.cr/2021/1314


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