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DeepMind AI agents find two weaknesses in legacy 1024-bit RSA — 2048-bit and larger still fine

SummaryHuman-guided agents reproduced a 1024-bit signature-oracle root with 3.5× less CPU than the prior academic run, and a new batch factoring method cuts average cost per extra 1024-bit key by about 30×. Paper: does not threaten deployed 2048+ RSA.

· MODEL Editors · 1 min read

Some links may be affiliate links. Disclosure

MODEL news card on a cream background. Small red kicker: RESEARCH. Large red figure: 3.5×. Headline: AI agents cut 1024-bit RSA attack cost. MODEL wordmark bottom left; Source: Google DeepMind bottom right.
DeepMind AI agents vs legacy 1024-bit RSA. 2048+ still fine. Not tested by MODEL. Illustration by MODEL. Original. Image source.

Google DeepMind published working papers showing that human-guided AI agents found two major weaknesses that affect legacy 1024-bit RSA cryptosystems — not modern 2048-bit and larger deployments. Pushmeet Kohli (VP Science) posted the explainer; co-authors include Dj Dvijotham and Abhradeep Thakurta, with collaborators Nadia Heninger (UCSD/Inria) and Emmanuel Thomé (Inria).

What the agents did. Two cooperating agents designed, ran, and debugged a 1024-bit computation (~33,500 new lines of code) in under about four days with roughly 20 human messages, peaking near 300k CPU cores.

Result 1 — signatures / padding. Once an attacker controls roughly half the signed block or more, PKCS-style padding adds no protection versus an unrestricted oracle. Agents reproduced a 1024-bit benchmark root with 3.5× less CPU time than the prior academic run (391 vs ~1,380 core-years) and under 1/1000 of the compute needed to break the key itself. For short 32-byte digests, a new algorithm improves about 1,600× (theoretical estimate) on 1024-bit.

Result 2 — batch factoring. A new algorithm cuts the average cost of factoring each additional 1024-bit key out of many by about 30× versus previous batch methods.

Who it's for: security researchers, crypto engineers measuring hardness, and anyone still running or auditing 1024-bit RSA.

Caveats (from the paper / posts). Results do not threaten deployed cryptosystems based on 2048-bit and larger RSA. The signature-oracle model assumes billions of chosen signing queries offline — not a casual internet attack. This is research, not a public product. MODEL has not tested it.

Disclosure: Not sponsored. No affiliate links. Not tested by MODEL.

MODEL Editors

Sources

  1. Faster Affine Root and a 1024-bit Computation (working paper PDF)

    Google DeepMind

  2. Fan Factories (working paper PDF)

    Google DeepMind

  3. DeepMind announcement

    @GoogleDeepMind on X

  4. Pushmeet Kohli explains (X Article)

    @Pushmeet on X

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