The post-quantum patent landscape is dominated by the names you would expect — Intel, IBM, banks, specialist crypto firms. It is therefore worth noting a deep, sustained family that traces largely to a single named inventor, John A. Nix, whose two-KEM key-establishment work this desk has covered before. In 2024 that family added several more granted patents.

Three stand out. US12003629B2, “Secure server digital signature generation for post-quantum cryptography key encapsulations” (June 2024), ties server-side signing to PQC key encapsulation. US12088706B2, “Device securing communications using two post-quantum cryptography key encapsulation mechanisms” (September 2024), continues the signature two-KEM hedge directly. And US12047516B2, “Combined digital signature algorithms for security against quantum computers” (July 2024), applies the same hedging instinct to signatures.

“A network and a device can support a secure session with both (i) multiple post-quantum cryptography (PQC) key encapsulation mechanisms (KEM) and (ii) forward secrecy.”— U.S. Patent No. 12,003,629 source

The unifying idea across the family is refusal to bet on a single post-quantum primitive. The earlier work combined two key encapsulation mechanisms so that breaking one did not break the shared secret; the combined-signature grant extends that to signatures, where two algorithms are composed so a future break of one does not forge the whole. The CPC tags cluster around H04L 9/0852 and the signature codes — the heart of quantum-resistant key establishment and authentication.

This hedging philosophy is exactly what the standards community worries about in practice. The newly standardized post-quantum algorithms have not endured decades of attack, so a structural defense — combine two independent primitives, require both to be broken — is a hedge against any single scheme proving weaker than believed. The family stakes that hedge across both encryption and signatures.

Per the desk's rules: these are issued grants (B2), not applications, so the claims cleared examination; and they describe methods, not shipped products. The recurrence of one inventor across half a decade of grants is the noteworthy pattern.

For the portfolio reader, this is a reminder that influential cryptography IP does not only come from corporate labs. A focused individual inventor, filing persistently in a narrow, important niche — hedged post-quantum key establishment — can assemble a family that anyone building hybrid PQC systems will eventually have to reckon with.