The blockchain technology has become a foundation of decentralized digital infrastructures, allowing secure, transparent, and tamper-resistant transactions in the finance and governance systems as well as supply chains ecosystems. But, existing blockchain systems are critically dependent on classical cryptography including RSA, ECDSA and hash-based primitives, which are becoming more susceptible to new entrant quantum computing. The quantum algorithm, especially Shor and Grover ones are a real challenge to the digital signatures, key exchange systems, and consensus integrity, which makes the sustainability of blockchain systems a serious concern in the long term.The practical approach of achieving quantum-resilient security without the use of quantum hardware-specific devices has seen considerable popularity in the form of Post-Quantum Cryptography (PQC). Although the literature is mostly concentrated on algorithm design, there is little work on the topic of architectural implementation of PQC in the framework of decentralized blockchain solutions. This chapter offers a systematic discussion on quantum threats, review of the most prominent families of PQC algorithms and suggests suitable deployment-related options to deploy quantum-safe cryptographic tools to blockchain systems. The chapter identifies trade-offs between security, scalability, and performance through comparative assessment and real-world case analysis, including PQC testnets in development and enterprise blockchain projects. The most important contribution of this work is the ability to introduce the gap between theory of cryptographic developments and the aspects of practical blockchain implementation challenges, providing an overall framework of the transition towards quantum-resilient distributed systems. The results would assist the researchers, practitioners and policy makers, to develop a future-proof blockchain architecture that would be in place to withstand digital trust in post-quantum age.
The blockchain technology has become a foundation of decentralized digital infrastructures, allowing secure, transparent, and tamper-resistant transactions in the finance and governance systems as well as supply chains ecosystems. But, existing blockchain systems are critically dependent on classical cryptography including RSA, ECDSA and hash-based primitives, which are becoming more susceptible to new entrant quantum computing. The quantum algorithm, especially Shor and Grover ones are a real challenge to the digital signatures, key exchange systems, and consensus integrity, which makes the sustainability of blockchain systems a serious concern in the long term.The practical approach of achieving quantum-resilient security without the use of quantum hardware-specific devices has seen considerable popularity in the form of Post-Quantum Cryptography (PQC). Although the literature is mostly concentrated on algorithm design, there is little work on the topic of architectural implementation of PQC in the framework of decentralized blockchain solutions. This chapter offers a systematic discussion on quantum threats, review of the most prominent families of PQC algorithms and suggests suitable deployment-related options to deploy quantum-safe cryptographic tools to blockchain systems. The chapter identifies trade-offs between security, scalability, and performance through comparative assessment and real-world case analysis, including PQC testnets in development and enterprise blockchain projects. The most important contribution of this work is the ability to introduce the gap between theory of cryptographic developments and the aspects of practical blockchain implementation challenges, providing an overall framework of the transition towards quantum-resilient distributed systems. The results would assist the researchers, practitioners and policy makers, to develop a future-proof blockchain architecture that would be in place to withstand digital trust in post-quantum age.
The advent of quantum computing poses an existential threat to contemporary cryptographic standards, particularly those securing decentralized blockchain networks and cloud infrastructures.Classical public-key cryptosystems such as RSA, ECC, and DH, which rely on factorization and discrete logarithm problems, are rendered obsolete by Shor's algorithm, necessitating the transition toward post-quantum cryptographic (PQC) solutions.This study explores the integration of PQC algorithms, including lattice-based, hash-based, code-based, multivariate, and isogeny-based cryptographic mechanisms, within blockchain-ledger technologies and cloud architectures to ensure long-term security against quantum adversaries.A comparative analysis is conducted to evaluate computational efficiency, key size implications, communication overhead, and security resilience under quantum attack models.The research highlights the adaptation of PQC within blockchain consensus mechanisms, smart contract execution, and cryptographic primitives such as digital signatures, zero-knowledge proofs, and secure multi-party computation (MPC).Additionally, it examines the impact of PQC on cloud security, addressing challenges in quantum-safe key exchange protocols, homomorphic encryption for secure computations, and cross-platform interoperability within hybrid quantum-classical cloud ecosystems.Real-world implementations and benchmarking data provide insights into the feasibility of large-scale adoption, shedding light on standardization efforts by NIST and industry consortia.The study concludes with future directions, emphasizing the need for efficient PQC algorithm optimization, lightweight cryptographic frameworks for IoT-driven blockchain applications, and scalable post-quantum identity management systems.By establishing quantum-resistant security frameworks, this research underscores the imperative need for early adoption to mitigate cryptographic vulnerabilities in the impending post-quantum era.
The concept of blockchain technology has transformed the digital ecosystem to allow decentralized, transparent and immutable transactions in various sectors. Its security is closely dependent on classical cryptography like ECDSA and RSA to perform digital signatures and SHA-256 to achieve consensus, which are becoming more susceptible to quantum computing. The cryptographic principles underpinning blockchain could be compromised with the emergence of the quantum algorithms of Shor and Grover, endangering the integrity of transactions, authentication and consensus protocols. This paper discusses the implications that quantum computing could have on blockchain security, analyses vulnerabilities of current cryptographic primitives and assesses post-quantum cryptographic (PQC) protocols, including lattice-based protocols, hash-based protocols, and code-based protocols. To guarantee backwards compatibility, as well as a gradual upgrade process to quantum-resistant protocols, a hybrid migration approach that involves transactions with two signatures is suggested. Experimental analysis shows that PQC integration attains reasonable performance trade-offs, that preserve verification costs, block size growth, and throughput effects within feasible limits, and that zero-loss resilience is achieved during reorganization tests. The conclusion is that blockchains with PQC support can reach post-quantum levels of security without major operation interruption, and they provide a viable roadmap to moving towards distributed ledger systems that are future-ready.
The fast-growing development of quantum computing is a great threat to classical cryptographic protocols underpinning the security of blockchain networks. The use of quantum attacks on algorithms, like RSA and Elliptic Curve Cryptography (ECC) used to perform digital signatures and verify transactions, is susceptible to the quantum attack, especially the Shor algorithm. This is an emerging risk that casts doubt on long term reliability and trustworthiness of blockchain systems in their various applications in the fields of finance to the field of healthcare. To overcome this difficulty, new cryptographic primitives exist, developed by the field of post quantum cryptography (PQC), which resist quantum computational power, such as lattice based, hash based, multivariate and code based. This paper examines how quantum-resistant cryptographic algorithms can be implemented into blockchain architecture, and how their security, scalability, and performance impacts can be assessed. Moreover, there are hybrid schemes that adapt classical and quantum safe schemes are taken as the transitional schemes to make backward compatibility. This study identifies practical avenues towards realising quantum resilient blockchain systems that are capable of supporting security in the post quantum era by analysing and comparing their possible implementations.
Classical blockchain cryptographic primitives are susceptible to quantum computing technology due to its unprecedented growth because it has the potential to make current blockchain encryption techniques obsolete against quantum attacks. Shor algorithm can perform transactional hijacking and forge digital signatures to impersonate blockchain users. On the other hand, Grover algorithm can perform 51% attack and can accelerate brute force attack by detecting hash collisions to replace the blocks of a blockchain. With the advent of this threat, in attempt to mitigate the effects of quantum attacks on blockchain technology, the concept of post-quantum cryptography (PQC) or quantum resistant cryptography (QRC) has emerged. PQC involves cryptographic algorithms or cryptosystems that are robust against quantum attacks and are also applicable in blockchain for post quantum decentralization. In this article, we provide a brief overview of quantum threats to classical blockchain technology. We identify and discuss some important requirements for the implementation of PQC. Moreover, we also identify and explain notable unresolved challenges in implementing PQC algorithms. We also determine critical research questions for each identified challenge that are imperative to confer and requires discussion and interpretation by the researchers of this field.
As quantum computing advances, classical public-key cryptosystems face escalating risks, driving global standardization efforts by NIST, ETSI, and ISO. This paper provides a comprehensive review of recent developments in post-quantum cryptography (PQC), focusing on lattice-based, hash-based, and multivariate approaches. We examine their security foundations, implementation challenges, and applicability across domains such as finance, blockchain, and the Internet of Things (IoT). A core contribution is the proposed Hybrid Cryptographic Framework (HCF), which combines classical and quantum-resistant primitives to enable a secure and interoperable migration path. The framework integrates hybrid key exchange, dual-signature schemes, and PQC-compatible Merkle trees, and is supported by a discrete multi-objective optimization model for selecting algorithms under real-world constraints. The paper also discusses deployment challenges, including hardware acceleration, side-channel resistance, and legacy compatibility. Real-world case studies illustrate how leading institutions are piloting PQC integration in practice. Finally, we propose a strategic roadmap for PQC adoption, incorporating adaptive triggers based on quantum capabilities and evolving threat models. By aligning cryptographic design with international standards and practical system requirements, this work offers guidance for building resilient, quantum-safe infrastructures.
Classical blockchain cryptographic primitives are susceptible to quantum computing technology due to its unprecedented growth because it has the potential to make current blockchain encryption techniques obsolete against quantum attacks. Shor algorithm can perform transactional hijacking and forge digital signatures to impersonate blockchain users. On the other hand, Grover algorithm can perform 51% attack and can accelerate brute force attack by detecting hash collisions to replace the blocks of a blockchain. With the advent of this threat, in attempt to mitigate the effects of quantum attacks on blockchain technology, the concept of post-quantum cryptography (PQC) or quantum resistant cryptography (QRC) has emerged. PQC involves cryptographic algorithms or cryptosystems that are robust against quantum attacks and are also applicable in blockchain for post quantum decentralization. In this article, we provide a brief overview of quantum threats to classical blockchain technology. We identify and discuss some important requirements for the implementation of PQC. Moreover, we also identify and explain notable unresolved challenges in implementing PQC algorithms. We also determine critical research questions for each identified challenge that are imperative to confer and requires discussion and interpretation by the researchers of this field.