Matthew Green has been writing a rather pessimistic series of posts about the potential for AI systems to vastly outperform humans in cryptanalysis of both symmetric and public-key ciphers.
I am more optimistic than he is. That is, I have stronger faith in the over-engineering cryptographers tend to do. I am trying to write this up in more detail.
Dave Sanford • October 14, 2026 11:38 AM
If AIs can solve the Navier-Stokes existence and smoothness problem, they can probably do this. I’m concerned that AI-driven offensive and defensive cryptanalysis could spark a new arms race.
Study4Pass • October 14, 2026 12:46 PM
Your optimism about over-engineering is reassuring, but it raises a question for me: does that margin protect us mainly against incremental improvements, or also against a genuinely novel attack idea? Human cryptanalysis has historically advanced in jumps — differential, linear, side channels — not just faster brute force. If AI’s edge is in combining techniques and searching spaces humans would never explore by hand, the worry isn’t that it out-computes us, but that it finds a structural shortcut we assumed was impractical to discover. I’m curious whether your longer write-up will address how much of that safety margin is mathematical versus merely ‘nobody has found the trick yet.’ As someone studying cryptography fundamentals through Study4Pass, this distinction between a cipher being strong and being merely unbroken so far is the part I find hardest to internalize.
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Sidebar photo of Bruce Schneier by Joe MacInnis.
Ferentarius • October 14, 2026 10:40 AM
Re: “I’m not going to get a prize for being right, and everyone will make fun of me for being wrong“
To be right is a barren victory, and to be wrong is a public crucifixion. Life is a theater where applause and ridicule are equally hollow; the only authentic moment is the one in which we recoil from both.