@inproceedings{3fba5b7c2cde4460b1468790fc5b4e67,
title = "The beauty and the beasts—The hard cases in LLL reduction",
abstract = "In this paper, we will systematically study who indeed are the hard lattice cases in LLL reduction. The “hard” cases here mean for their special geometric structures, with a comparatively high “failure probability” that LLL can not solve SVP even by using a powerful relaxation factor. We define the perfect lattice as the “Beauty”, which is given by basis of vectors of the same length with the mutual angles of any two vectors to be exactly 60°. Simultaneously the “Beasts” lattice is defined as the lattice close to the Beauty lattice. There is a relatively high probability (e.g. 15.0% in 3 dimensions) that our “Beasts” bases can withstand the exact-arithmetic LLL reduction (relaxation factors δ close to 1), comparing to the probability (corresponding <0.01%) when apply same LLL on random bases from TU Darmstadt SVP Challenge. Our theoretical proof gives us a direct explanation of this phenomenon. Moreover, we give rational Beauty bases of 3 and 8 dimensions, an irrational Beauty bases of general high dimensions. We also give a general way to construct Beasts lattice bases from the Beauty ones. Experimental results show the Beasts bases derived from Beauty can withstand LLL reduction by a stable probability even for high dimensions. Our work in a way gives a simple and direct way to explain how to build a hard lattice in LLL reduction.",
keywords = "Hard cases, Lattice, LLL reduction, Post-quantum cryptography",
author = "Saed Alsayigh and Jintai Ding and Tsuyoshi Takagi and Yuntao Wang",
note = "Publisher Copyright: {\textcopyright} Springer International Publishing AG 2017.; 12th International Workshop on Security, IWSEC 2017 ; Conference date: 30-08-2017 Through 01-09-2017",
year = "2017",
doi = "10.1007/978-3-319-64200-0_2",
language = "English",
isbn = "9783319641997",
series = "Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)",
publisher = "Springer Verlag",
pages = "19--35",
editor = "Satoshi Obana and Koji Chida",
booktitle = "Advances in Information and Computer Security - 12th International Workshop on Security, IWSEC 2017, Proceedings",
}