https://eprint.iacr.org/2024/555 What a lovely hat Is it made out of tin foil? IACR Logo Cryptology ePrint Archive * Papers Updates from the last: + 7 days + 31 days + 6 months + 365 days + ------------------------------------------------------------- + Listing by year + All papers + Compact view + ------------------------------------------------------------- + How to cite + ------------------------------------------------------------- + Harvesting metadata * Submissions + Submit a paper + Revise or withdraw a paper + Acceptance and publishing conditions * About + Goals and history + News + Statistics + Contact Search Button [ ] Search Advanced search Paper 2024/555 Quantum Algorithms for Lattice Problems Yilei Chen[orcid], Tsinghua University, Shanghai Artificial Intelligence Laboratory, Shanghai Qi Zhi Institute Abstract We show a polynomial time quantum algorithm for solving the learning with errors problem (LWE) with certain polynomial modulus-noise ratios. Combining with the reductions from lattice problems to LWE shown by Regev [J.ACM 2009], we obtain polynomial time quantum algorithms for solving the decisional shortest vector problem (GapSVP) and the shortest independent vector problem (SIVP) for all $n$-dimensional lattices within approximation factors of $\tilde{\ Omega}(n^{4.5})$. Previously, no polynomial or even subexponential time quantum algorithms were known for solving GapSVP or SIVP for all lattices within any polynomial approximation factors. To develop a quantum algorithm for solving LWE, we mainly introduce two new techniques. First, we introduce Gaussian functions with complex variances in the design of quantum algorithms. In particular, we exploit the feature of the Karst wave in the discrete Fourier transform of complex Gaussian functions. Second, we use windowed quantum Fourier transform with complex Gaussian windows, which allows us to combine the information from both time and frequency domains. Using those techniques, we first convert the LWE instance into quantum states with purely imaginary Gaussian amplitudes, then convert purely imaginary Gaussian states into classical linear equations over the LWE secret and error terms, and finally solve the linear system of equations using Gaussian elimination. This gives a polynomial time quantum algorithm for solving LWE. Metadata Available format(s) [file-pdf]PDF Publication info Preprint. Contact author(s) chenyilei ra @ gmail com History 2024-04-10: approved 2024-04-10: received See all versions Short URL https://ia.cr/2024/555 License Creative Commons Attribution CC BY BibTeX [copy-outli]Copy to clipboard @misc{cryptoeprint:2024/555, author = {Yilei Chen}, title = {Quantum Algorithms for Lattice Problems}, howpublished = {Cryptology ePrint Archive, Paper 2024/555}, year = {2024}, note = {\url{https://eprint.iacr.org/2024/555}}, url = {https://eprint.iacr.org/2024/555} } IACR Logo Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.