Questions tagged [lenstra-lenstra-lovasz]
The Lenstra–Lenstra–Lovász (LLL) lattice basis reduction algorithm efficiently finds a short, nearly orthogonal lattice basis form an arbitrary one
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Size upper bound on LLL-reduced basis
Suppose $\Lambda$ is a lattice in $\mathbb{Z}^m$ and let $\{b_1, ..., b_n\}$ be an LLL-reduced basis, rename these vectors as $v_1, ... , v_n$ such that $1 \leq ||v_1|| \leq ... \leq ||v_n||$. How can ...
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Gram-Schmidt coefficients in LLL algorithm
To my understanding the LLL lattice reduction algorithm starts with a set of integer vectors $\{b_1, \dots, b_2\}$, which span a lattice, and tries to generate a new basis of shorter vectors of the ...
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Introduction to LLL algorithm applied to linear modular inequalities
What is the Lenstra–Lenstra–Lovász lattice basis reduction algorithm about?
How is it applied to solve for $x\pmod m$ a system of modular inequalities $(u_i\,x+v_i\bmod m)<w$ for $0\le i<n$?
I'm ...
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Lattice reduction question regarding the capability of LLL and BKZ
I've been reading How to estimate the hardness of SIS instances? and following some of its sources, and I want to confirm a few things.
LLL algorithm runs in polynomial time, but isn't capable of ...
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LLL - Lattice Reduced Basis Algorithm question?
I have two related questions:
Version 1: Let $B=\{b_1,b_2,\dots,b_n\}$ be an orthogonal basis for $R^n$. What is the associated reduced basis obtained by applying LLL algorithm to $B$?
I know how ...
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What is the minimal angle between two LLL reduced vectors?
What is the minimal angle between two LLL reduced vectors?
It seems it should be 60 degree as $|\mu_{i,j}| \leq \frac{1}{2}$.
If we make the upper bound of $\mu_{i,j}$ by 1/3, can we get better ...
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$L^3$ Grover search of NTRU variants
I was reading a text on cryptology by Wayne Patterson and came across the $L^3$ algorithm which reduces integer lattices with respect to their base. I've also read on the NIST CFP A8 that attacks ...
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Significance of Gram-Schmidt coefficients in LLL algorithm
Let $\{ {\bf v}_1,{\bf v}_2 \}$ be two linearly independent vectors. An orthogonal base $\{{\bf u}_1,{\bf u}_2 \}$ of the vector space $\mathrm{span}\{ {\bf v}_1,{\bf v}_2 \}$ can be computed using ...
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Why is the Lovász condition used in the LLL algorithm?
The LLL algorithm is used to approximate the Shortest Vector Problem, i.e., it outputs a reduced basis. Such a basis will satisfy two conditions:
$$ \forall i \gt j. \quad \lvert\mu_{ij}\rvert \le \...
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Problem with LLL reduction on truncated LCG schemes
I am struggling to apply Freize et al. paper to break a truncated LCG.
A truncated LCG is a pseudo random generator that outputs the $n$ leading bits $y_i$ of $x_i$, where $(x_i)$ is such that $x_{...
