Post-quantum Attacks Reshape Blockchain, Threatening Security and Performance
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The increasing potential of quantum computing presents a fundamental threat to the cryptographic foundations of modern digital infrastructure, including the blockchain technologies that underpin many secure transactions. Tushin Mallick, Maya Zeldin, and Murat Cenk, from Northeastern University and Ripple Inc, alongside Cristina Nita-Rotaru of Northeastern University, investigate how these emerging quantum capabilities reshape blockchain security and performance. Their work addresses a critical challenge: simply replacing existing cryptographic tools with quantum-resistant alternatives is not enough, and can even introduce new vulnerabilities or severely impact operational efficiency.
This research systematically examines the specific points of weakness within blockchain architectures and evaluates how different post-quantum cryptographic adaptations affect system performance, trust mechanisms, and the overall viability of decentralised networks, offering crucial insights for building truly quantum-resistant blockchain systems. Blockchain Security and Post-Quantum Cryptography This comprehensive study explores the evolving landscape of blockchain technology, with a particular focus on the critical need for post-quantum cryptography (PQC) and improved scalability. Researchers investigated several major blockchains, assessing their vulnerabilities to potential attacks from future quantum computers and evaluating potential solutions to enhance both performance and security. The work represents a thorough examination of the field, laying the groundwork for further investigation and development. The study highlights the significant threat that quantum computers pose to current blockchain cryptography, as most platforms rely on algorithms susceptible to attacks from Shor’s algorithm. A central theme is the urgent need to transition to PQC algorithms, designed to resist attacks from both classical and quantum computers. Researchers examined various PQC approaches and their potential implementation across different blockchain networks. The study also identifies scalability as a major obstacle to wider blockchain adoption, noting limitations in transaction throughput and storage capacity. The research provides a comparative analysis of prominent blockchains, including Bitcoin, Ripple (XRP), and Algorand, assessing each platform’s strengths, weaknesses, and approaches to both PQC and scalability. The study acknowledges the importance of Layer-2 scaling solutions as a means of improving throughput without altering the core blockchain structure. Researchers also note the increasing storage demands of blockchain networks, which present challenges for node operators and network decentralization. Blockchain Cryptography and Post-Quantum Vulnerability Assessment This research undertakes a detailed evaluation of post-quantum (PQC) preparedness across seven prominent blockchain platforms, selected for their diverse architectural designs and significant presence within the blockchain ecosystem. Researchers meticulously examined these platforms, representing proof-of-work, proof-of-stake, byzantine fault tolerance, and proof-of-history consensus mechanisms, to assess their resilience against emerging quantum threats. The work focuses on identifying cryptographic components vulnerable to quantum attacks and evaluating the feasibility of integrating proposed PQC solutions within existing blockchain designs. To achieve this, the team conducted a detailed survey of each blockchain’s cryptographic foundations and consensus protocols, pinpointing specific areas susceptible to attacks from quantum algorithms. This involved analyzing how each platform currently utilizes digital signatures, key exchange protocols, and hash-based constructions, and then assessing the potential impact of quantum computing on these core functionalities. The study then evaluated countermeasures proposed by each blockchain, including the adoption of lattice-based signature schemes and Winternitz One-Time Signature schemes for account recovery. Furthermore, the research rigorously analyzed the performance implications of adopting PQC signature schemes, specifically focusing on throughput, latency, and block interval.
The team investigated how larger signature and public key sizes, characteristic of many PQC algorithms, affect on-chain data size, network propagation speeds, and overall ledger growth. Simulations and analyses were conducted to determine how these factors impact the number of transactions per block and the potential for degradation in system efficiency and scalability.
Blockchain Security Transitions to Post-Quantum Cryptography This work examines the implications of adopting post-quantum cryptography within blockchain systems, focusing on four key areas of impact. The study identifies vulnerabilities within existing blockchain architectures, particularly in consensus mechanisms, identity management, and transaction validation, and surveys proposed adaptations to post-quantum primitives. Researchers demonstrate that simply replacing current cryptographic tools with post-quantum alternatives is insufficient, requiring careful architectural redesign to maintain both security and operational efficiency. The analysis of seven prominent blockchains reveals the cryptographic foundations underpinning their operation. Bitcoin relies on ECDSA for transaction authentication and SHA-256 for its Proof-of-Work puzzle, while Ethereum utilizes ECDSA, BLS, and KZG commitments alongside Keccak-256 hashing and VDFs within its Proof-of-Stake consensus. Algorand employs FALCON signatures and SHA-256 hashing with a Pure Proof-of-Stake mechanism, and Solana uses EdDSA and W-OTS signatures with Keccak-256 hashing and Proof of History. Avalanche utilizes ECDSA and SHA-256/Ripemd160 with its Snowman consensus, while Monero employs EdDSA and Keccak-256 with Proof of Work. XRPL uses EdDSA and ECDSA with SHA-256 and RPCA. Ethereum’s transition to Proof-of-Stake in September 2022 is highlighted, demonstrating a shift towards more energy-efficient consensus. Researchers note that Ethereum finalizes blocks approximately every 6. 4 minutes after two-thirds of validators attest to their correctness. Ethereum supports two account types, Externally Owned Accounts and Contract Accounts, forming the basis for decentralized applications. Researchers also note that Ethereum supports zk-SNARKs for enhanced privacy and scalability, and account abstraction for flexible verification logic.
Blockchain Security Requires Architectural Redesign The emergence of quantum computing presents a significant challenge to the security of blockchain systems, which currently rely on cryptographic methods vulnerable to quantum attacks.
This research demonstrates that simply replacing existing cryptographic primitives with post-quantum alternatives is insufficient; a more comprehensive redesign of blockchain architectures is necessary. The study identifies vulnerabilities within key blockchain components, including consensus mechanisms, identity management, and transaction validation, and analyzes how post-quantum adaptations impact system performance and operational efficiency. Findings reveal that integrating post-quantum signature schemes introduces trade-offs affecting scalability, latency, and the incentive structures that underpin blockchain ecosystems. Researchers determined that maintaining both security and performance requires careful consideration of protocol design and governance, extending beyond mere cryptographic substitution. While acknowledging that transitioning to post-quantum cryptography is complex, the work emphasizes the need for coordinated standardization, hybrid cryptographic infrastructures, and a sustained balance between security, performance, and decentralization. The authors note that the analysis focuses on current blockchain designs and that future innovations may offer alternative solutions. Further research is needed to explore the long-term implications of post-quantum cryptography and to develop practical strategies for mitigating the risks posed by quantum computers to blockchain security. 👉 More information 🗞 Quantum Disruption: An SOK of How Post-Quantum Attackers Reshape Blockchain Security and Performance 🧠 ArXiv: https://arxiv.org/abs/2512.13333 Tags: