Paper 2026/1992 Original: eprint.iacr.org/2026/1992 ↗

Bridging the Cryptographic Transition: A Unified Framework for Post-Quantum Key Exchange

Abstract

In a widely publicized recent announcement, Google established a formal 2029 deadline for completing its post-quantum cryptography (PQC) migration---one that deliberately preempts the 2035 deadline set by NIST and the US federal government to complete the deprecation of classical public-key algorithms. Google cited faster-than-expected progress across three fronts: quantum computing hardware development; quantum error correction; and revised estimates of the resources required for quantum computers to break current cryptographic schemes; as motivation for setting an ambitious internal target ahead of the regulatory horizon. This tightened deadline places particular pressure on existing cryptographic protocols that rely on classical key exchange primitives for secure communication. Our work aims to ease this transition by constructing a unified, formally analyzed security framework for migrating classical key exchange constructions to their post-quantum counterparts.