Mythos attack on 3rd-round PQC algorithm candidate puts it out of commission
Anthropic's Mythos AI model identified a critical weakness in the HAWK digital signature algorithm, leading its developer to withdraw the scheme from the NIST post‑quantum cryptography competition. The attack, which required about 60 hours of compute and $100,000 in resources, effectively halved the algorithm's key strength by discovering a new method for finding automorphism symmetries. While the underlying mathematical problem remains considered safe, the finding highlights the growing role of AI in cryptanalysis and may affect the selection of future quantum‑resistant standards.
- ▪Anthropic's Mythos AI model uncovered a previously unknown attack on the HAWK signature scheme, prompting its withdrawal from the NIST PQC evaluation.
- ▪The attack reduced HAWK's effective key strength by about half and could be mitigated only by doubling the key size, making it less competitive.
- ▪The discovery was made using existing cryptographic techniques combined in a novel way, without introducing new mathematics.
- ▪The research required roughly 60 hours of computation and $100,000 in costs, demonstrating the feasibility of AI‑assisted cryptanalysis.
Ars Technica files mainly under tech. We currently carry 170 of its stories.
Story provenance
Source · retrieval · rights · ranking — open for full record
inspect →
Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | Ars Technica |
| Canonical URL | https://arstechnica.com/security/2026/07/mythos-uncovers-crypto-weaknesses-that-went-unknown-for-years/ |
| Publication time | Wed, 29 Jul 2026 22:07:06 +0000 |
| Retrieval time | 2026-07-30T00:08:16.814Z |
| Last seen | 2026-07-30T00:08:16.814Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | F6IRuiVwpNwN · 1 stories |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
AI-GENERATED CRYPTANALYSIS Mythos attack on 3rd-round PQC algorithm candidate puts it out of commission HAWK withstood years of testing that had yet to uncover a fatal weakness found through Mythos. Dan Goodin – Jul 29, 2026 6:07 pm | 16 Credit: Getty Images Credit: Getty Images Text settings Story text Size Small Standard Large Width * Standard Wide Links Standard Orange * Subscribers only Learn more Minimize to nav A quantum-resistant cryptography algorithm that was under consideration as an official US standard has been taken out of the running after an Anthropic security model helped find a flaw that rendered it broken. The algorithm is known as HAWK. It’s a digital signature scheme designed to withstand future attacks from quantum computers.
…
Excerpt limited to ~120 words for fair-use compliance. The full article is at Ars Technica.
Discussion
0 commentsMore from Ars Technica
