Architecting Quantum-Resilient Blockchains: A Systems Framework for Post-Quantum Security, Governance, and Migration

Quantum computing poses a significant threat to blockchain systems that rely on elliptic curve cryptography and other classical security mechanisms. Algorithms such as Shor’s and Grover’s can weaken or completely break the cryptographic foundations of current blockchain networks, exposing them to risks including private key recovery, transaction forgery, consensus manipulation, and harvest-now-decrypt-later attacks. This paper presents a systems framework for designing quantum-resilient blockchains by integrating post-quantum cryptographic standards, threat modeling, architectural redesign, governance mechanisms, and migration planning. The study evaluates major post-quantum cryptographic primitives, assesses their suitability for blockchain environments, and proposes a layered architecture grounded in crypto-agility, defense-in-depth, and forward secrecy. A structured migration strategy is also introduced to support the transition of existing blockchain networks toward post-quantum security while maintaining operational continuity and stakeholder trust. The framework provides practical guidance for researchers, developers, and policymakers preparing blockchain ecosystems for the post-quantum era.