Abstract The advancement of quantum attacks has posed a significant threat to blockchain cryptosystems. Furthermore, the finite lifecycles of ciphertext and keys may result in data leakage risks for long-term storage due to potential breaches in ciphertext security, necessitating ciphertext updates. Ensuring the long-term security of cryptographic algorithms on blockchains against quantum attacks has emerged as a critical concern in blockchain research. A blockchain oracle serves as a mechanism for data communication. The Module-Learning with Errors (MLWE) problem is a significant issue in lattice-based cryptography, providing security against quantum attacks. To resist the threat of quantum attacks on encrypted data and ensure the long-term security, this study proposed an updatable encryption (UE) scheme for blockchain oracles based on post-quantum cryptography. First, this study developed a UE scheme based on the blockchain oracle architecture, enabling the oracle to update encrypted data via update tokens, ensuring the data's long-term security. Additionally, a UE algorithm based on the MLWE problem was introduced to enhance its resistance to quantum attacks. Finally, an error-correcting mechanism tailored for the UE algorithm was developed to validate transmitted data, correct errors, and improve the scheme's robustness. The experimental results demonstrate that the proposed scheme not only provides quantum-resistant security but also enables ciphertext updates through update tokens. Compared to existing schemes, it has more advantages in protecting data security.
Abstract The advancement of quantum attacks has posed a significant threat to blockchain cryptosystems. Furthermore, the finite lifecycles of ciphertext and keys may result in data leakage risks for long-term storage due to potential breaches in ciphertext security, necessitating ciphertext updates. Ensuring the long-term security of cryptographic algorithms on blockchains against quantum attacks has emerged as a critical concern in blockchain research. A blockchain oracle serves as a mechanism for data communication. The Module-Learning with Errors (MLWE) problem is a significant issue in lattice-based cryptography, providing security against quantum attacks. To resist the threat of quantum attacks on encrypted data and ensure the long-term security, this study proposed an updatable encryption (UE) scheme for blockchain oracles based on post-quantum cryptography. First, this study developed a UE scheme based on the blockchain oracle architecture, enabling the oracle to update encrypted data via update tokens, ensuring the data's long-term security. Additionally, a UE algorithm based on the MLWE problem was introduced to enhance its resistance to quantum attacks. Finally, an error-correcting mechanism tailored for the UE algorithm was developed to validate transmitted data, correct errors, and improve the scheme's robustness. The experimental results demonstrate that the proposed scheme not only provides quantum-resistant security but also enables ciphertext updates through update tokens. Compared to existing schemes, it has more advantages in protecting data security.
The rapid advancement of quantum computing poses a significant threat to classical cryptographic methods used in blockchain-based healthcare systems. Existing security mechanisms such as RSA and ECC are vulnerable to quantum attacks, posing a risk to patient data integrity, confidentiality, and authentication mechanisms. To address this challenge, postquantum cryptographic (PQC) solutions, including lattice-based, hash-based, code-based, and multivariate polynomial-based techniques, have been proposed. This study systematically reviews and classifies PQC methods and their integration into blockchainbased healthcare infrastructures. A three-layer security model is discussed to enhance blockchain resilience against quantum attacks. The study further explores on-chain, off-chain, and crosschain security mechanisms within healthcare applications to ensure secure medical data storage, patient identity management, and interoperability among healthcare providers. The findings suggest that hybrid cryptographic models, combining classical and post-quantum techniques, provide a practical transition strategy for ensuring long-term security in blockchain networks. This research contributes to the field by offering a structured classification of quantum-resistant blockchain security mechanisms and providing insights into future research directions, particularly in the areas of quantum-safe healthcare data management, performance optimization of PQC methods, and the development of quantum-resistant smart contracts.
With the development of quantum computing, classical cryptosystems (RSA, ECDSA) that ensure the security of distributed ledgers face an existential threat. This paper examines protocols for protecting personal data (PD) in blockchain, taking into account the “Harvest Now, Decrypt Later” strategy. We propose and formalize a family of protocols designed for storing and exchanging personal data in blockchain systems. The article describes in detail approaches to software implementations of smart contracts for the Ethereum (using ECIES (Elliptic Curve Integrated Encryption Scheme) and Keccak-256) and Hyperledger Fabric 2.5 (integrating NIST post-quantum standards: ML-KEM (Module-Lattice-Based Key Encapsulation Mechanism) and ML-DSA (Module-Lattice-Based Digital Signature Algorithm)) platforms based on the developed protocols. For all developed protocols, a Threat Agent Model (TAM) is presented, threat scenarios are examined, and resilience to typical attack scenarios is demonstrated. A comparative analysis of computational efficiency and overhead is conducted. The results show that using lattice cryptography provides high performance, but the 50-fold increase in signature size makes direct implementation of PQC (Post-Quantum Cryptography) in Layer 1 public networks economically unfeasible. A hybrid model and the use of Layer 2 to ensure quantum resistance are proposed.
The advancement of quantum computing poses a significant threat to classical cryptographic algorithms, particularly those based on factorization and discrete logarithm problems. In this paper, we propose a secure and quantum-resistant key exchange scheme leveraging the FrodoKEM algorithm, a lattice-based post-quantum key encapsulation mechanism designed to resist attacks from quantum adversaries. FrodoKEM, being based on the Learning with Errors (LWE) problem, offers a conservative and standard approach to post-quantum cryptography without relying on structured lattices. We compare the performance and security of the proposed scheme against traditional key exchange mechanisms such as RSA and Elliptic Curve Diffie-Hellman (ECDH), as well as other post-quantum algorithms like Kyber and NTRU. Our analysis demonstrates that FrodoKEM offers improved security assurances and competitive performance metrics, especially in environments where long-term confidentiality and forward secrecy are critical. The experimental results affirm FrodoKEM's suitability for real-world deployment in post-quantum secure communications.
With the fast-paced development of quantum computing, classical cryptographic techniques are under severe security threats, prompting the need for post-quantum cryptographic mechanisms for secure data exchange in next-generation network communications. Post-quantum cryptography seeks to protect sensitive data against quantum attacks to provide long-term data confidentiality. But all current cryptographic techniques, including RSA and ECC, are susceptible to quantum algorithms like Shor's algorithm, which can factor large integers efficiently and break discrete logarithm problems, making classical cryptography useless. There is thus a pressing need for quantum attack-resistant encryption mechanisms. To meet these challenges, we introduce the Lattice-Based Cryptography with Hybrid Key Exchange (L-CHKE) framework, which combines lattice-based encryption with a hybrid key exchange mechanism. Lattice-based cryptography provides quantum resistance because it is based on hard mathematical problems such as Learning with Errors (LWE), which provides greater security and efficiency. The designed L-CHKE algorithm strengthens secure key distribution and authentication for next-generation networks, especially for applications needing strong security like financial transactions, IoT, and military communications. Experimental results verify that L-CHKE noticeably boosts computational efficiency by 98.45%, decreases key exchange latency by 42.56%, and guarantees robustness by 97.64% against quantum attacks, indicating it is an appropriate solution for post-quantum secure communication.
This paper presents a comprehensive examination of post-quantum cryptographic techniques, also known as quantum encryption, which offer protection against quantum attacks. It explores various methods such as hash-based cryptography and lattice-based cryptography that can safeguard cryptographic hashing and encryption against the potential vulnerabilities posed by quantum computers. The focus is specifically on the implications for blockchain technology, as it is susceptible to compromise during quantum attacks. The study provides an overview of quantum cryptographic encryption techniques that are poised to withstand quantum attacks, ensuring the resilience and quantum-proof nature of cryptographic measures. Blockchain is a peer to peer network that maintains distributed ledger. The peers in the network shares information in the network that is secured using typical cryptographic mechanisms. The proposed system aims at integrating quantum resistant cryptographic techniques in the blockchain network which ensures enhanced security to the information shared in the network. The proposed algorithm improves level of security to the typical blockchain network.
The exponential advancement of quantum computing poses unprecedented threats to conventional cryptographic systems employed in banking infrastructure. This paper presents a comprehensive quantum-enhanced cryptographic framework that integrates post-quantum algorithms with distributed ledger technologies to establish resilient financial security systems. Through systematic analysis of lattice-based cryptography, hash-based signatures, and multivariate cryptographic schemes, this research demonstrates significant improvements in computational security while maintaining operational efficiency. The proposed framework achieves 99.7% security resilience against quantum attacks while reducing transaction processing overhead by 23% compared to traditional RSA-based systems. Experimental validation across simulated banking environments reveals enhanced performance metrics in key generation, digital signatures, and secure communication protocols. The integration of quantum-resistant algorithms with blockchain-based consensus mechanisms provides a robust foundation for future-proof banking security architectures.