We construct the first fully homomorphic encryption (FHE) scheme that encrypts matrices and supports homomorphic matrix addition and multiplication. This is a natural extension of packed FHE and thus supports more complicated homomorphic operations. We optimize the bootstrapping procedure of Alperin-Sheriff and Peikert (CRYPTO 2014) by applying our scheme. Our optimization decreases the lattice approximation factor from Õ(n3) to Õ(n2.5). By taking a lattice dimension as a larger polynomial in a security parameter, we can also obtain the same approximation factor as the best known one of standard lattice-based public-key encryption without successive dimension-modulus reduction, which was essential for achieving the best factor in prior works on bootstrapping of standard lattice-based FHE.
Ryo HIROMASA
Kyoto University
Masayuki ABE
NTT Corporation
Tatsuaki OKAMOTO
NTT Corporation
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Ryo HIROMASA, Masayuki ABE, Tatsuaki OKAMOTO, "Packing Messages and Optimizing Bootstrapping in GSW-FHE" in IEICE TRANSACTIONS on Fundamentals,
vol. E99-A, no. 1, pp. 73-82, January 2016, doi: 10.1587/transfun.E99.A.73.
Abstract: We construct the first fully homomorphic encryption (FHE) scheme that encrypts matrices and supports homomorphic matrix addition and multiplication. This is a natural extension of packed FHE and thus supports more complicated homomorphic operations. We optimize the bootstrapping procedure of Alperin-Sheriff and Peikert (CRYPTO 2014) by applying our scheme. Our optimization decreases the lattice approximation factor from Õ(n3) to Õ(n2.5). By taking a lattice dimension as a larger polynomial in a security parameter, we can also obtain the same approximation factor as the best known one of standard lattice-based public-key encryption without successive dimension-modulus reduction, which was essential for achieving the best factor in prior works on bootstrapping of standard lattice-based FHE.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/transfun.E99.A.73/_p
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@ARTICLE{e99-a_1_73,
author={Ryo HIROMASA, Masayuki ABE, Tatsuaki OKAMOTO, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={Packing Messages and Optimizing Bootstrapping in GSW-FHE},
year={2016},
volume={E99-A},
number={1},
pages={73-82},
abstract={We construct the first fully homomorphic encryption (FHE) scheme that encrypts matrices and supports homomorphic matrix addition and multiplication. This is a natural extension of packed FHE and thus supports more complicated homomorphic operations. We optimize the bootstrapping procedure of Alperin-Sheriff and Peikert (CRYPTO 2014) by applying our scheme. Our optimization decreases the lattice approximation factor from Õ(n3) to Õ(n2.5). By taking a lattice dimension as a larger polynomial in a security parameter, we can also obtain the same approximation factor as the best known one of standard lattice-based public-key encryption without successive dimension-modulus reduction, which was essential for achieving the best factor in prior works on bootstrapping of standard lattice-based FHE.},
keywords={},
doi={10.1587/transfun.E99.A.73},
ISSN={1745-1337},
month={January},}
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TY - JOUR
TI - Packing Messages and Optimizing Bootstrapping in GSW-FHE
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 73
EP - 82
AU - Ryo HIROMASA
AU - Masayuki ABE
AU - Tatsuaki OKAMOTO
PY - 2016
DO - 10.1587/transfun.E99.A.73
JO - IEICE TRANSACTIONS on Fundamentals
SN - 1745-1337
VL - E99-A
IS - 1
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - January 2016
AB - We construct the first fully homomorphic encryption (FHE) scheme that encrypts matrices and supports homomorphic matrix addition and multiplication. This is a natural extension of packed FHE and thus supports more complicated homomorphic operations. We optimize the bootstrapping procedure of Alperin-Sheriff and Peikert (CRYPTO 2014) by applying our scheme. Our optimization decreases the lattice approximation factor from Õ(n3) to Õ(n2.5). By taking a lattice dimension as a larger polynomial in a security parameter, we can also obtain the same approximation factor as the best known one of standard lattice-based public-key encryption without successive dimension-modulus reduction, which was essential for achieving the best factor in prior works on bootstrapping of standard lattice-based FHE.
ER -