Post-Quantum Hybrid Key Exchange in Network Runtimes: Architectural Foundations for Modern Systems

Moving to post-quantum cryptography is an immediate operational need rather than a distant goal. Recent empirical benchmarks from NowSecure evaluating over 136,000 mobile and enterprise applications reveal that 97% of software currently lacks post-quantum readiness, leaving systems dangerously exposed to "Harvest Now, Decrypt Later" (HNDL) attacks. Hostile actors are actively capturing encrypted network traffic today to decrypt it once quantum computers are ready. With Shor's algorithm, a quantum machine can cut the time needed to break classical public-key encryption from thousands of years down to a few hours. Since new lattice-based algorithms have not yet been tested in production for decades, like older methods, the Internet Engineering Task Force (IETF) and the Java Community Process have introduced hybrid key exchange standards. However, most current migration guides only talk about replacing cipher names in code and ignore the packet fragmentation and memory slowdowns caused by large post-quantum keys. In this paper, we present the building blocks of our framework, PQ-STRATA (Post-Quantum Systems Transport and Runtime Adaptation). PQ-STRATA pairs automated Abstract Syntax Tree (AST) discovery with an offline, privacy-compliant (DPDP/GDPR) local language model (Gemma) for secure code remediation. Furthermore, our framework keeps production systems fast by tuning infrastructure layers, integrating ETSI-compliant Quantum Key Distribution (QKD), and isolating High-Frequency Trading (HFT) data paths.