Quantum-Resistant Blockchain Protocols: A Future-Proof Architecture for Secure Distributed Ledgers

Abstract

Blockchain technologies underpin many of today’s decentralized applications, yet their long‐term
security is threatened by the advent of large‐scale quantum computing. Classical cryptographic primitives such as
RSA, Elliptic Curve Digital Signature Algorithm (ECDSA) and Diffie-Hellman key‐exchange are vulnerable to
quantum algorithms (e.g., Shor’s algorithm, Grover’s algorithm). This paper presents a comprehensive architecture
for quantum-resistant blockchain systems (QR-blockchains). We (1) analyse the quantum threat landscape and
identify vulnerability points in typical blockchain stacks; (2) survey and compare post-quantum cryptographic
(PQC) techniques (lattice-based, hash-based, code-based, multivariate) and their suitability for blockchain; (3)
propose a modular blockchain architecture with cryptographic agility, hybrid-signature support, quantum-resistant
consensus layers, and migration strategies; (4) evaluate performance trade-offs (key/sig sizes, throughput, latency,
storage overhead) and security implications; and (5) outline deployment challenges and future research directions.
Our work provides a blueprint for future-proofing distributed ledger systems in the quantum era.