# A new paper by Daniel Simon might indicate lattice based crypto (ML-KEM etc) breaks with quantum computers

**URL:** https://discuss.privacyguides.net/t/a-new-paper-by-daniel-simon-might-indicate-lattice-based-crypto-ml-kem-etc-breaks-with-quantum-computers/39691
**Category:** News
**Tags:** article
**Created:** 2026-08-07T10:23:36Z
**Posts:** 19
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## Post 1 by @maqp — 2026-08-07T10:23:36Z

The paper in question:

> **[A Polynomial-Time Quantum Algorithm for the Dihedral Coset Problem](https://eprint.iacr.org/2026/1591)**
>
> We present a polynomial-time quantum algorithm for the Dihedral Coset Problem (DCP). The algorithm is based on Regev's polynomial-time reduction of the Dihedral Subgroup Problem (DSP) to the modular subset sum problem, but uses a different technique...

The author also developed Simon’s algorithm that inspired the Shor’s algorithm. The paper hasn’t been peer-reviewed yet.

There’s some analysis by Marin Ivenzic [Simon Claims Polynomial-Time DCP Quantum Algorithm](https://postquantum.com/security-pqc/simon-quantum-algorithm-lattice-pqc/)

Also [a Reddit thread](https://www.reddit.com/r/crypto/comments/1vgylui/a_polynomialtime_quantum_algorithm_for_the/).

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