Korean Pre-AGI AI startup VIDRAFT has announced the successful demonstration of quantum cryptanalysis targeting symmetric-key cipher structures, using IBM's 156-qubit quantum computer. The company shared results showing that hidden periods within specific cryptographic structures could be recovered directly on real quantum hardware — a meaningful step forward in applied quantum security research.
According to a report by 이코노미스트, the experiments focused on two well-known symmetric-key cipher architectures: the Even-Mansour construction and a three-round reduced Feistel structure. Rather than attacking production-grade encryption systems, VIDRAFT framed the work as a proof-of-concept aimed at exploring how quantum algorithms perform against the internal mathematical structures underlying these cipher designs.
The team applied Simon's algorithm — a quantum algorithm known for its exponential speedup in identifying hidden periodicities — to the Even-Mansour construction, successfully recovering hidden periods across a range of input sizes. For the reduced Feistel structure, the experiments were conducted at two different block sizes, and hidden periods were identified in both configurations. To strengthen confidence in the results, a self-verification procedure was incorporated into each experimental instance: for every run, a distinct secondary key was recovered alongside the hidden period, allowing the team to cross-check outcomes against actual quantum hardware outputs.
VIDRAFT noted that comparable demonstrations on publicly accessible real quantum hardware had, for years, remained limited to much smaller input sizes, making this the largest-scale public demonstration of its kind to date.
Importantly, the company was careful to contextualize the significance of these results. The experiments did not break AES, DES, or any cryptographic system currently deployed in financial or enterprise environments. The Feistel structure tested was a simplified, reduced-round variant — not the full DES standard. Additionally, the experiments were carried out without quantum error correction, relying instead on noise mitigation techniques. VIDRAFT explicitly stated that the results should not be interpreted as quantum computers outperforming classical computers in a general sense; rather, the value lies in running quantum cryptanalytic algorithms at a larger scale than previously demonstrated on noisy, real-world quantum hardware.
Alongside the experimental findings, VIDRAFT released a publicly accessible quantum cryptanalysis toolkit covering five cipher structures: linear ciphers, block ciphers using Substitution-Permutation Networks (SPN), Even-Mansour, CBC-MAC, and Feistel constructions. The tool is browser-based and is designed to let users interactively explore how quantum algorithms operate against each of these structures.
CEO Kim Min-sik commented that quantum computers, once fully mature, are expected to become indispensable tools for tackling complex scientific challenges across drug discovery, advanced materials, and cybersecurity. He reaffirmed the company's intention to continue pursuing empirical research that combines AI and quantum computing.
VIDRAFT, which develops AI applications for pharmaceuticals, materials science, and public administration — built on its proprietary Darwin language model family and AETHER architecture — indicated it plans to pursue academic publication and independent external validation of these experimental results.
As post-quantum cryptography standards continue to take shape globally, research that stress-tests the real-world capabilities of quantum hardware against classical cryptographic primitives — however preliminary — offers a grounded picture of where the technology actually stands today.
Source: 이코노미스트 (2026-07-08) — original article