Matthew Green: "I think we might lose public key cryptography"

Cryptographer Matthew Green warned that advances in mathematics and related research could undermine public-key cryptography, specifically encryption, prompting concern about whether widely used asymmetric primitives might become insecure. The comment came amid discussion about recent math breakthroughs and questions about undisclosed attacks, with observers asking how many novel vulnerabilities might exist now but remain unreleased and what the landscape could look like in one or five years. Several participants urged close attention to guidance from defense and standards bodies such as DoD, NSA, and NIST. The exchange generated large public engagement, reflecting alarm in the community about potential near‑term disruption to systems that rely on asymmetric encryption.

Responses stressed that the claim is speculative and highlighted limits from complexity theory - invoking P vs NP - and pointed to existing fallback approaches, including post‑quantum families and hash‑based schemes like SHRINCS for use cases such as signatures. Green later clarified he meant encryption rather than every public‑key primitive. The substantive takeaway is a sharp, public warning that research breakthroughs could force accelerated migration and contingency planning for cryptographic infrastructure, even as experts debate how likely a wholesale collapse of asymmetric schemes really is.