On November 6, 2026, Google DeepMind announced that AI agents had uncovered two distinct weaknesses in legacy 1024-bit RSA cryptosystems — a result that would have taken human researchers considerably longer to find.
The key word here is legacy. RSA-1024 was deprecated years ago and is no longer used in modern secure systems. But it persists in older infrastructure, industrial equipment, and embedded systems that haven't been updated. That's where these findings matter.
What was found
DeepMind's agents, guided by human cryptanalysis experts, identified two separate flaws:
- A signature forgery weakness that is estimated to be roughly 1,600 times more efficient than brute-force approaches — meaning an attacker could forge RSA-1024 signatures far more cheaply than previously understood.
- A batch factoring shortcut that reduces the cost of factoring 1024-bit keys by approximately 30 times when multiple keys share structure, as often happens in bulk device provisioning.
Pushmeet Kohli, DeepMind's VP of Science, was explicit on scope: modern 2048-bit keys remain unaffected. This is not a break of RSA as used in TLS, SSH, or current certificate infrastructure.
Why AI found it faster
The AI agents were deployed in an adversarial search mode: given the mathematical structure of RSA-1024, they explored the space of potential attack vectors more systematically than a human team could over months of analysis. The process still required human cryptographers to validate the findings and structure the problem correctly — but the search itself ran in weeks, not years.
This is consistent with a broader trend: AI is increasingly useful not at replacing cryptographers, but at dramatically compressing the time it takes to explore a large problem space under expert guidance.
What you should do
If you're responsible for infrastructure, the action item is straightforward: audit your systems for RSA-1024 key usage. This applies especially to embedded devices, IoT hardware, and any legacy VPN or certificate authority still issuing 1024-bit keys. Migrate to RSA-2048 or, better, to elliptic-curve cryptography (ECDSA/Ed25519), which provides stronger guarantees at smaller key sizes.
For everyone else: RSA-1024 has been on the "do not use" list for over a decade. DeepMind's announcement is a timely reminder of why that guidance exists — and a striking demonstration of what AI-assisted cryptanalysis can accomplish.
Sources: OfficeChai · DEV Community · Crypto Briefing · RuntimeWire