@inproceedings{00e0925e39824099b7585c0f2f4eae6a,
title = "A lattice attack on homomorphic NTRU with non-invertible public keys",
abstract = "In 2011, Stehl{\'e} and Steinfeld modified the original NTRU to get a provably IND-CPA secure NTRU under the hardness assumption of standard worst-case problems over ideal lattices. In 2012, L{\'o}pez-Alt et al. proposed the first multikey fully homomorphic encryption scheme based on the IND-CPA secure NTRU. Interestingly, this homomorphic NTRU and subsequent homomorphic variants of NTRU removed the condition {\textquoteleft}invertible public key{\textquoteright} of the underlying IND-CPA secure NTRU. In this paper, we investigate the security influence of using non-invertible public key in the homomorphic NTRU. As a result, we present how to mount a lattice attack to message recovery for the homomorphic NTRU when the public key is non-invertible. Our result suggests that using invertible public keys in the homomorphic NTRU is necessary for its security.",
keywords = "Homomorphic NTRU, IND-CPA security, Lattices, LLL algorithm, NTRU",
author = "Soyoung Ahn and Lee, {Hyang Sook} and Seongan Lim and Ikkwon Yie",
note = "Funding Information: Acknowledgement. Hyang-Sook Lee and Seongan Lim were supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2015R1A2A1A15054564). Seongan Lim was also supported by Basic Science Research Program through the NRF funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2016R1D1A1B01008562). Ikkwon Yie was supported by Basic Science Research Program through the NRF funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2017R1D1A1B03034721). Funding Information: Hyang-Sook Lee and Seongan Lim were supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2015R1A2A1A15054564). Seongan Lim was also supported by Basic Science Research Program through the NRF funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2016R1D1A1B01008562). Ikkwon Yie was supported by Basic Science Research Program through the NRF funded by the Ministry of Science, ICT and Future Planning (Grant Number: 2017R1D1A1B03034721). Publisher Copyright: {\textcopyright} Springer International Publishing AG, part of Springer Nature 2018.; 19th International Conference on Information and Communications Security, ICICS 2017 ; Conference date: 06-12-2017 Through 08-12-2017",
year = "2018",
doi = "10.1007/978-3-319-89500-0_22",
language = "English",
isbn = "9783319894997",
series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",
publisher = "Springer Verlag",
pages = "248--254",
editor = "Sihan Qing and Dongmei Liu and Chris Mitchell and Liqun Chen",
booktitle = "Information and Communications Security - 19th International Conference, ICICS 2017, Proceedings",
}