RT Journal Article T1 Revisiting multivariate ring learning with errors and Its applications on lattice-based cryptography A1 Pedrouzo Ulloa, Alberto A1 Troncoso Pastoriza, Juan Ramón A1 Gama, Nicolas A1 Georgieva, Mariya A1 Perez Gonzalez, Fernando K1 1201 Álgebra K1 3304 Tecnología de Los Ordenadores K1 1203.17 Informática AB The “Multivariate Ring Learning with Errors” problem was presented as a generalization of Ring Learning with Errors (RLWE), introducing efficiency improvements with respect to the RLWE counterpart thanks to its multivariate structure. Nevertheless, the recent attack presented by Bootland, Castryck and Vercauteren has some important consequences on the security of the multivariate RLWE problem with “non-coprime” cyclotomics; this attack transforms instances of m-RLWE with power-of-two cyclotomic polynomials of degree n=∏ini into a set of RLWE samples with dimension maxi{ni}. This is especially devastating for low-degree cyclotomics (e.g., Φ4(x)=1+x2). In this work, we revisit the security of multivariate RLWE and propose new alternative instantiations of the problem that avoid the attack while still preserving the advantages of the multivariate structure, especially when using low-degree polynomials. Additionally, we show how to parameterize these instances in a secure and practical way, therefore enabling constructions and strategies based on m-RLWE that bring notable space and time efficiency improvements over current RLWE-based constructions. PB Mathematics SN 22277390 YR 2021 FD 2021-04-14 LK http://hdl.handle.net/11093/2112 UL http://hdl.handle.net/11093/2112 LA eng NO Mathematics, 9(8): 858 (2021) NO Agencia Estatal de Investigación (España) | Ref. PID2019-105717RB-C21 DS Investigo RD 03-oct-2024