Provable Lattice Reduction of $\mathbb Z^n$ with Blocksize $n/2$

ePrint Report: Provable Lattice Reduction of $\mathbb Z^n$ with Blocksize $n/2$

Léo Ducas

The Lattice Isomorphism Problem (LIP) is the computational task of recovering, assuming it exists, a orthogonal linear transformation sending one lattice to another. For cryptographic purposes, the case of the trivial lattice $\mathbb Z^n$ is of particular interest ($\mathbb Z$LIP). Heuristic analysis suggests that the BKZ algorithm with blocksize $\beta = n/2 + o(n)$ solves such instances (Ducas, Postlethwaite, Pulles, van Woerden, ASIACRYPT 2022).


In this work, …

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