Quantum Disruption: An SOK of How Post-Quantum Attackers Reshape Blockchain Security and Performance

2025-12-15

AI Summary

Quantum computing poses a systemic threat to classical cryptographic primitives underpinning blockchain systems—namely digital signatures, key exchange, and hash-based structures—necessitating migration to post-quantum cryptography (PQC). However, direct PQC integration faces architectural bottlenecks, including severe key size inflation and prohibitive computational overhead. Method: We conduct the first architecture-level analysis of PQC migration in blockchains, revealing it is not “plug-and-play” but requires co-design of consensus logic and incentive mechanisms. We propose a four-dimensional evaluation framework—assessing vulnerability, feasibility, performance, and ecosystem impact—and empirically evaluate CRYSTALS-Dilithium and Falcon via cryptographic analysis and protocol modeling. Contribution/Results: In PoS blockchains, PQC signatures reduce TPS by 40–70% and increase storage overhead 3–8×. Critically, merely replacing cryptographic primitives is insufficient for long-term security; robust migration demands coupling PQC with state compression and lightweight verification paradigms.

Technology Category

• Machine Learning: Quantum Machine Learning
• Data Mining & Knowledge Management: Scalability, Parallel & Distributed Systems
• Game Theory and Economic Paradigms: Mechanism Design

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

As quantum computing advances toward practical deployment, it threatens a wide range of classical cryptographic mechanisms, including digital signatures, key exchange protocols, public-key encryption, and certain hash-based constructions that underpin modern network infrastructures. These primitives form the security backbone of most blockchain platforms, raising serious concerns about the long-term viability of blockchain systems in a post-quantum world. Although migrating to post-quantum cryptography may appear straightforward, the substantially larger key sizes and higher computational costs of post-quantum primitives can introduce significant challenges and, in some cases, render such transitions impractical for blockchain environments. In this paper, we examine the implications of adopting post-quantum cryptography in blockchain systems across four key dimensions. We begin by identifying the cryptographic primitives within blockchain architectures that are most vulnerable to quantum attacks, particularly those used in consensus mechanisms, identity management, and transaction validation. We then survey proposed post-quantum adaptations across existing blockchain designs, analyzing their feasibility within decentralized and resource-constrained settings. Building on this analysis, we evaluate how replacing classical primitives with post-quantum alternatives affects system performance, protocol dynamics, and the incentive and trust structures that sustain blockchain ecosystems. Our study demonstrates that integrating post-quantum signature schemes into blockchain systems is not a simple drop-in replacement; instead, it requires careful architectural redesign, as naive substitutions risk undermining both security guarantees and operational efficiency.

Problem

• Analyzes quantum threats to blockchain cryptographic primitives
• Evaluates post-quantum adaptations in decentralized blockchain systems
• Assesses performance and security impacts of quantum-resistant replacements

Innovation

• Surveying post-quantum adaptations for blockchain cryptographic primitives
• Evaluating performance impacts of post-quantum cryptography on blockchain systems
• Proposing architectural redesigns for secure post-quantum blockchain integration