Blockchain Papers

Thomas den Hollander, Daniel Slamanig

No abstract is available for this record.

Wu-Sheng Wang, Masahito Hayashi

On-demand authentication is critical for scalable quantum systems, yet many existing quantum signature and message-authentication schemes are signer-initiated, requiring advance distribution of authentication material even when no verification occurs. We introduce verifier-initiated quantum digital signatures (VIQDS), in which the verifier requests authentication only when needed and the signer responds once; after issuance, verification proceeds without further interaction. Practically, shifting authentication to a verifier-driven, on-demand workflow reduces avoidable communication and storage overhead and aligns with deployments where verification is sporadic, such as distributed services and audit-oriented infrastructures. Our approach leverages quantum zero-knowledge techniques so that verification reveals nothing about the signer’s secret key beyond the fact that the signature is valid. We present a general conversion principle from suitable quantum proof protocols to VIQDS, together with a concrete realization based on elementary qubit platforms. Here, we show information-theoretic security against forgery and privacy against curious verifiers without computational hardness assumptions. The authors introduce a verifier-initiated quantum message-authentication method, in which authentication is requested only when needed. Their approach uses quantum zero knowledge techniques to protect information about the signer’s secret key while providing information-theoretic security against forgery

Al Thani, Jamil

This comprehensive technical specification details the ADN-NChain protocol, a first-of-its-kind Distributed Ledger Technology (DLT). It introduces a revolutionary self-repairing neural blockchain architecture, leveraging biologically-inspired genetic algorithms for state management and unprecedented network resilience to systemic and quantum threats. The whitepaper thoroughly covers the robust system design, the novel Proof-of-Resonance (PoR) consensus mechanism, and a future-proof post-quantum cryptography implementation (CRYSTALS-Dilithium) essential for securing the next generation of crypto-assets and decentralized applications (dApps). Performance metrics confirm high scalability (12,000+ TPS) and exceptional data integrity with a 99.9% automatic corruption repair success rate. This work is critical for researchers, investors, and developers focused on next-generation blockchain, Web3, cryptocurrency security, and Decentralized Finance (DeFi) solutions.

Chol Hyun Park, Misael Ocas Olguin

The arrival of quantum computing poses a huge threat to conventional public key cryptography used in blockchain systems such as Bitcoin. To address this challenge, we proposes and evaluates a quantum resistant sidechain framework that integrates post quantum digital signature schemes and quantum key distribution (QKD) protocols with the Bitcoin mainchain. Using a Python simulation environment, the performance of multiple signature algorithms. ECDSA as a baseline measurement, Falcon, CRYSTALS-Dilithium, and SPHINCS+ were analyzed in combination with quantum communication protocols BB84, E91, and SARG04. Experimental results show that ECDSA remains the fastest baseline scheme but lacks quantum resistance, while SPHINCS+ provides the highest security with an expected overhead of 93.5 %. Among quantum protocols, BB84 achieved the best overall efficiency across transaction sizes. The optimal integration pairs were BB84 and CRYSTALS-Dilithium combination for speed, security balance and SPHINCS+ and E91 for maximum quantum resilience. These findings demonstrate the practical feasibility of deploying post quantum cryptographic components in Bitcoin compatible sidechains, paving the way for future blockchain networks that remain secure in the post quantum era.

Xihan Zhao

With the rapid development of quantum computing technology, traditional encryption methods face severe security threats in multi-party privacy intersection protocols in federated learning. In this paper, we propose a new protocol based on post-quantum cryptography. Firstly, lattice-based homomorphic encryption and zero-knowledge proof technology are used to achieve key generation and parameter initialization against quantum attacks. Secondly, ciphertext data encoding is carried out to support homomorphic operations. Next, a zero-knowledge proof is used to verify the correctness of the ciphertext intersection calculation. Finally, the protocol is embedded into the federated learning workflow, adaptively adjusting the parameters. Experimental results show that the protocol achieves the NIST (National Institute of Standards and Technology) security level 3, and the privacy leakage rate is less than 1.2%, the communication and computational costs are controllable, and the protocol does not bring great influence to the accuracy of the federated learning model. The experimental results verify that the protocol can provide a reliable protection for the privacy of federated learning data in the quantum era.

Odnala Srinivas, Sanghamitra Mohanty, Nihar Ranjan Pradhan

This paper presents a quantum-enhanced blockchain architecture addressing the dual challenges of quantum vulnerability and scalability limitations in conventional distributed ledgers. We propose a novel framework integrating three key innovations the NIST-standardized Dilithium lattice-based cryptosystem for post-quantum encryption, quantum-resistant binary data structures (1011011 sequences) for integrity verification, and sharded post-quantum key management. Our experimental results demonstrate significant improvements over classical systems, achieving 2,542 TPS throughput (2.7× increase) and reducing cryptographic latency by 67% using BB84 quantum protocols. The architecture provides comprehensive protection against Shor’s and Grover’s algorithms while maintaining blockchain’s decentralized principles through a hybrid quantum-classical consensus mechanism. Comparative analysis reveals our solution outperforms both RSA (classical) and Kyber (hybrid) in all evaluated metrics, including encryption speed (325 MB/s) and key generation time (112 ms). This work establishes a practical pathway for transitioning blockchain infrastructures to quantum-resistant paradigms without compromising performance.

Yosef Bonaparte

Blockchain technology has emerged as the backbone of cryptocurrencies and decentralized finance, yet its long-term resilience is increasingly threatened by advances in quantum computing. Quantum algorithms, such as Shor’s algorithm, can undermine public-key cryptography, while Grover’s algorithm accelerates brute-force search, weakening proof-of-work schemes. In this paper, we propose a Quantum Blockchain Framework that integrates quantum communication protocols, quantum consensus mechanisms, and quantum-resistant cryptography. We construct a theoretical model of quantum-secured distributed ledgers, where qubits, entanglement, and quantum key distribution (QKD) enhance security and efficiency. Applications to cryptocurrency are explored, highlighting how quantum blockchain can mitigate security risks, improve consensus speed, and enable quantum-native digital assets.

Sergey V. Grebnev, Yevgenii Melnichuk, Irina Poltavskaya, Oleg Turchenko · 6 authors

No abstract is available for this record.

James Hsin-yu Chiang, Ivan Damgård, William R. Duro, Sunniva Engan · 6 authors

We propose efficient, post-quantum threshold ring signatures constructed from one-wayness of AES encryption and the VOLE-in-the-Head zero-knowledge proof system. Our scheme scales efficiently to large rings and extends the linkable ring signatures paradigm. We define and construct key-binding deterministic tags to achieve linkability. We then extend our threshold ring signatures to realize post-quantum anonymous ledger transactions in the spirit of Monero. Finally, our deterministic tags also enable succinct aggregation using approximate lower bound arguments of knowledge; this allows us to achieve succinct (approximate) multi-signatures without SNARKs. Our constructions assume symmetric key primitives only.

Efe Büke

The rapid evolution of financial technologies (FinTech) and digital assets—including cryptocurrencies, decentralized finance (DeFi), and tokenized capital markets—has created an unprecedented need for secure, scalable, and computationally efficient systems. This study examines the transformative potential of quantum computing in reshaping financial technology infrastructures and digital asset ecosystems. Traditional computational models, constrained by classical encryption limits and the exponential growth of financial data, face increasing inefficiencies in handling real-time risk assessment, portfolio optimization, and transaction verification. Quantum computing, with its capacity for superposition, entanglement, and parallel state evaluation, provides novel opportunities to redefine data security, financial modeling, and cryptographic mechanisms in the digital economy. The research explores how quantum algorithms—notably Quantum Approximate Optimization Algorithm (QAOA), Quantum Fourier Transform (QFT), and Grover’s search algorithm—can enhance financial operations such as market forecasting, fraud detection, and asset pricing. Additionally, it investigates quantum-resistant cryptography to safeguard digital asset networks against the vulnerabilities introduced by future quantum decryption capabilities. By integrating hybrid quantum–classical frameworks, this approach enables the development of sustainable, adaptive, and transparent financial systems. The findings highlight quantum computing’s potential to advance financial inclusion, increase transaction speed, and improve systemic resilience. As global financial markets transition toward quantum readiness, the convergence of FinTech and quantum innovation is expected to redefine how digital assets are managed, traded, and secured—marking a paradigm shift toward quantum financial intelligence.

Efe Büke

The exponential growth of digital finance—encompassing online banking, digital assets, decentralized finance (DeFi), and algorithmic trading—has intensified the need for robust cybersecurity frameworks. However, the rise of quantum computing presents a dual challenge: while it enables revolutionary advances in data analytics and optimization, it simultaneously threatens the cryptographic foundations of contemporary financial systems. This research explores the emerging field of quantum cybersecurity and its implications for safeguarding financial infrastructures in the post-quantum era. Traditional encryption methods such as RSA, ECC, and Diffie–Hellman key exchange are vulnerable to quantum attacks, particularly through Shor’s algorithm and Grover’s search algorithm, which can efficiently break asymmetric and symmetric cryptographic schemes. The study evaluates quantum-resistant cryptographic protocols—including lattice-based, hash-based, and multivariate polynomial encryption—as viable solutions for ensuring financial data integrity, transaction confidentiality, and regulatory compliance in quantum-vulnerable environments. Furthermore, it investigates Quantum Key Distribution (QKD) and Quantum Random Number Generation (QRNG) as hardware-assisted techniques for achieving unconditional security in financial communications and transaction authentication. By integrating quantum cryptography, hybrid encryption, and AI-driven threat modeling, this work outlines a roadmap for financial institutions transitioning toward quantum-secure infrastructures. The findings demonstrate that quantum cybersecurity is not merely a defensive measure but a transformative enabler for resilient digital finance, aligning with global efforts to achieve technological sovereignty, financial stability, and sustainable innovation in the era of quantum computing.

Deni Teminyan

Decentralized finance (DeFi) uses smart contracts to automate payments, lending, and asset management, but current blockchains often suffer from slow, expensive, and energy-hungry execution. In this project, I explore a quantum-enhanced optimization framework for smart contract–based financial services. The main idea is to treat gas use, transaction ordering, and resource allocation as optimization problems that can be tackled by hybrid quantum–classical algorithms. Using a conceptual model, I map smart contract execution to cost functions suitable for the Quantum Approximate Optimization Algorithm (QAOA) and the Variational Quantum Eigensolver (VQE). I then compare, at a qualitative level, how these quantum-inspired approaches differ from classical heuristics in terms of expected throughput, latency, and cost. A focused literature review on quantum computing, blockchain scalability, and quantum-safe cryptography provides context for these ideas. The results suggest that quantum-enhanced optimization could reduce gas fees, improve transaction scheduling, and support more efficient consensus under heavy load. The project also discusses the need for post-quantum security so that future quantum computers do not undermine blockchain trust. Overall, the work outlines how quantum computing might contribute to faster, safer, and more sustainable automated financial systems.

Sai Srinivas Vellela, Lakshma Reddy Vuyyuru, Sudhir Kumar Jidugu, M. Purnachandra Rao · 6 authors

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.

Liviu Ionut Epure

The convergence of quantum physics and machine learning presents unprecedented opportunities for developing ultra-secure authentication systems. This comprehensive paper investigates the integration of quantum random number generators (QRNGs) with advanced machine learning architectures, including quantum neural networks (QNNs), long short-term memory (LSTM) networks, and hybrid quantumclassical models, to establish authentication mechanisms with information-theoretic security guarantees. We provide rigorous theoretical foundations spanning quantum entropy theory, min-entropy estimation, and randomness certification, complemented by detailed analyses of contemporary QRNG hardware implementations including photonic integrated circuits achieving generation rates exceeding 20 Gbps. The paper explores deep learning architectures for biometric authentication, demonstrating how QNN-enhanced systems achieve superior performance through quantum superposition and entanglement. Furthermore, we examine the application of quantum entropy sources in zero-knowledge proof protocols, particularly zk-SNARKs and zk-STARKs, addressing post-quantum security concerns. Through comprehensive mathematical formulations, algorithmic implementations, and security analyses, we establish that hybrid quantum-classical authentication systems combining QRNG-derived cryptographic keys with ML-based behavioral authentication provide provably secure, practical solutions for next-generation cybersecurity applications. Experimental results from current quantum hardware platforms validate theoretical predictions and demonstrate real-world applicability.

Ejiro U, Osiobe, Waleed A., Hammood, Safia, Malallah, Nyore E., Osiobe · 6 authors

Quantum mechanics principles underpin quantum computing, signaling a major shift in how we process information. While it offers immense processing power and potential advantages, it also presents significant challenges for the cryptocurrency industry. This sector has grown rapidly, supporting decentralized finance and empowering users worldwide, but it also attracts malicious actors looking to exploit its vulnerabilities. Traditional cryptography remains strong, yet increasingly sophisticated computational attacks threaten security. As the cryptocurrency market expands, quantum computing offers both opportunities, such as improved transaction security, and risks, like easier decryption for hackers. Understanding quantum technology’s benefits and challenges is crucial as it develops. Currently, data is protected by traditional cryptography, but future, more powerful quantum computers could weaken this security. This article explores potential uses of quantum computing in daily life and business, explains its functions simply, and discusses societal impacts. Its goal is to help students and general readers understand how quantum technology might transform our world through clear language and real-life examples. Topics include the basics of quantum computing, its present and future applications across industries, and its societal effects. We provide a thorough analysis of how quantum computing could reshape society through mathematical insights, practical examples, and future perspectives.

Rajesh Kumar

This research introduces a post-quantum crypto-infrastructure exploiting the CRYSTALS-Kyber lattice based key encapsulation and the CRYSTALS-Dilithium digital signature cryptography supporting the real time payment transactions against quantum computing based attacks. Besides, based on the open quantum safe library OpenQuantumSafe and TensorFlow Federated, a hybrid classical-quantum federated key management protocol for payment systems is built. With the system, transaction validation can be checked without decryption based on HOMORPHIC encryption using Microsoft SEAL toolkit with sub-200ms latency. For anomaly detection application in neural network, LSTM auto-encoder can detect quantum based attacks with an accuracy of 97.4%. Implementation on AWS Braket Simulator for Verification against Shor algorithm Quantum Resistance and Grover algorithm. The model delivered Redis heavily boronated, for high speed key caching, and Apache Kafka, for asynchronous streaming of transactions at a speed of 50,000 transactions per second. Securely storing the cryptographic keys using an integration with HSM PKCS#11 hardware interface Blockchain anchoring with Hyperledger Fabric: GDPR compliance audit trail immutability with zero-knowledge-proofs (libsnark).

Mishall Al-Zubaidie, Tuqa Ghani Tregi

The rapid progress of quantum computing poses significant challenges to traditional cryptographic mechanisms, necessitating the adoption of post-quantum cryptography (PQC) solutions. This paper proposes a Quantum-Enhanced Security for Smart Meters (QESM) system to protect power plant data in smart cities, integrating Kyber for secure key exchange, FALCON (Fast-Fourier Transform over Lattice-based Cryptography) for quantum-resistant digital signatures, and ZKP (Zero-Knowledge Proof) for effective verification without revealing sensitive data to secure power plant data against quantum attacks. To evaluate the security of the proposed system, we analyze its resistance to various quantum threats, including Shor’s algorithm, Grover’s algorithm, quantum key analysis, quantum reversal encryption, quantum amplification, quantum switching, and quantum collision attacks. In the current study, accurate measures were used and the average was approximately 7.065 (bits/byte) for randomness, the average execution time was 6.202 milliseconds, the average memory consumption was approximately 4.343 KB, 6.4 Completeness was equal to 1 and unforgeability was 100%. As for the average throughput, it was approximately 485,605 operations per second. That shows the QESM system provides strong security and efficiency, making it a viable solution for protecting the electricity infrastructure in smart cities in the quantum era.

Mario Yaksetig, Jiayu Xu

No abstract is available for this record.

Allan Edgard Silva Freitas

Quantum computing threatens foundational cryptographic assumptions in today’s distributed ledgers, while application demands outgrow the throughput and latency ceilings of single-chain blockchains. Directed acyclic graph (DAG) ledgers unlock parallelism but raise new questions about ordering, security, and light-client viability. This position paper argues for a postquantum (PQ) DAG ledger that matches DAG concurrency with PQ-secure consensus and transactions, plus a privacy-preserving identity/reputation layer. We sketch the architecture, situate it against the literature, and enumerate some open challenges to be addressed for deployment at scale. A carefully engineered PQ DAG can provide credible security and performance in a quantum-enabled adversarial landscape.

Dr. Robert Campbell, Sr.

The transition to post-quantum cryptography poses an unprecedented challenge for Bitcoin and Ethereum, as it involves implementing a defensive downgrade that imposes immediate, severe costs with no tangible benefits. While quantum computers capable of breaking secp256k1 require between 523–2,500 logical qubits, with the author deriving 523 logical qubits as an algorithmic lower bound (not inclusive of arithmetic and ancilla qubits) for a canonical Shor/phase-estimation circuit using the formula QL = 2⌈log2(n)⌉ + 2 + ⌈log2(2 + 1/(2ε))⌉ for ε = 0.001, and conservative estimates ranging up to 2,500 logical qubits based on comprehensive resource models—significantly less than the 2,100–2,400 logical qubits es- timated for general elliptic curves—current systems achieve only ∼100 logical qubits. IBM’s quantum roadmap projects 500–1,000 logical qubits by 2029, placing the critical threshold within 4–10 years depending on which estimate proves accurate. This timeline collides with the reality that convincing decentralized communities to accept 50% capacity loss and 2– 3× fee increases may take 10–15 years in themselves, based on historical governance patterns where even beneficial upgrades required 2–5+ years. Current testnet implementations on per- missioned systems show measurable performance degradation. Critically, this data comes from fundamentally different architectures than permissionless networks, which will likely experience 30–50% additional performance degradation due to global verification requirements, heterogeneous hardware, and compounding propagation delays. This methodological limitation—extrapolating from permissioned to permissionless systems—represents a critical infrastructure failure that introduces massive uncertainty into migration planning. Com- pounding this challenge, secp256k1 is not officially approved by NIST under FIPS 186-5 or SP 800-186, creating additional regulatory vulnerabilities. Beyond transient impacts, PQC creates permanent state bloat, with quantum-resistant accounts requiring 59 times more storage (1,952 bytes / 33 bytes = 59.2× for ML-DSA-65), thereby accelerating centralization- tion. This paper presents a comprehensive framework acknowledging these harsh realities. While we propose specific BIP/EIP implementations and optimization strategies that might achieve 50–60% capacity retention, we recognize that the quantum threat timeline may now be shorter than even the minimum viable migration period. Unlike beneficial upgrades like SegWit (which took 20 months for activation and 5+ years for 50% adoption despite offering improvements), PQC migration is a purely defensive measure imposing only costs. The stark reality: blockchain communities must choose between accepting immediate emergency action or facing quantum vulnerability by 2029.

Rabees Paroshan, Srivaitheeswari.M, Abhishek Kumar.S.A, S. Pavithra

Quantum computing has positioned itself as a serious threat to traditional cryptography, undermining the very foundation of present-day methods of transaction and the popularly used digital payment systems. Here lies an interest in proposing a platform that can remedy these quantum-age risks present in payment mechanisms. The intended aim thus becomes that of building a secure and scalable payment system that uses quantum computing algorithms to train AI models for fraud detection in real-time, QKD to manage key security, and PQC to securely encrypt transaction data. For privacy, ZKP will be used to verify the transaction without revealing any details from it. Also, the platform will integrate multichain blockchains with quantum sharding, allowing separate processing, and distribution of transaction storage. Experimental results have shown that the proposed platform can resist quantum attacks, attain more accuracy in ratio detection, and improve the transaction speed more than the average blockchain solutions. The novelty of this research stands on the enhanced multichain blockchain architecture and improved Zero-Knowledge Proof protocols, which improve scalability and privacy. By bringing multichain architecture, quantum computing, QKD, and PQC into one model, this platform sets the benchmark for a secure, scalable, and affordable digital payment system.

Chen, Chi-Sheng, Aidan Hung-Wen Tsai

This study presents a comprehensive empirical comparison between quantum machine learning (QML) and classical machine learning (CML) approaches in Automated Market Makers (AMM) and Decentralized Finance (DeFi) trading strategies through extensive backtesting on 10 models across multiple cryptocurrency assets. Our analysis encompasses classical ML models (Random Forest, Gradient Boosting, Logistic Regression), pure quantum models (VQE Classifier, QNN, QSVM), hybrid quantum-classical models (QASA Hybrid, QASA Sequence, QuantumRWKV), and transformer models. The results demonstrate that hybrid quantum models achieve superior overall performance with 11.2\% average return and 1.42 average Sharpe ratio, while classical ML models show 9.8\% average return and 1.47 average Sharpe ratio. The QASA Sequence hybrid model achieves the highest individual return of 13.99\% with the best Sharpe ratio of 1.76, demonstrating the potential of quantum-classical hybrid approaches in AMM and DeFi trading strategies.

Mohammed Ziaul Haider, Tayyaba Noreen, Mishah Uzziél Salman, Marcos Dias de Assunção · 5 authors

Cross-chain bridges and oracle DAOs represent some of the most vulnerable components of decentralized systems, with more than 2.8 billion lost due to trust failures, opaque validation behavior, and weak incentives. Current oracle designs are based on multisigs, optimistic assumptions, or centralized aggregation, exposing them to attacks and delays. Moreover, predictable committee selection enables manipulation, which threatens data integrity across chains. We propose V-ZOR, a verifiable oracle relay that integrates zero-knowledge proofs, quantum-grade randomness, and cross-chain restaking to mitigate these risks. Each oracle packet includes a Halo 2 proof verifying that the reported data was correctly aggregated using a deterministic median. To prevent committee manipulation, VZOR reseeds its VRF using auditable quantum entropy, ensuring unpredictable and secure selection of reporters. Reporters stake once on a shared restaking hub; any connected chain can submit a fraud proof to trigger slashing, removing the need for multisigs or optimistic assumptions. A prototype in Sepolia and Scroll achieves sub-300k gas verification, one-block latency, and a $\mathbf{1 0} \times$ increase in collusion cost. V-ZOR demonstrates that combining ZK attestation with quantum-randomized restaking enables a trust-minimized, high-performance oracle layer for cross-chain DeFi.

Jamil Abedalrahim Jamil Alsayaydeh, Mohd Faizal Yusof, Nor Adnan Yahaya, Viacheslav Kovtun · 5 authors

In today's digital world, cryptocurrencies like Bitcoin can secure transactions without banks. However, the rise of quantum computing poses significant threats to their security, as traditional cryptographic methods may be easily compromised. In addition, the existing algorithms face difficulties like slow transaction speeds, interoperability issues between different cryptocurrencies, and privacy concerns. Hence, Quantum Crypto Guard for Secure Transactions (QCG-ST), a novel blockchain framework, is introduced, offering enhanced security and efficiency for cryptocurrency transactions. The QCG-ST employs lattice-based cryptography to provide robust protection against quantum threats and incorporates a new consensus mechanism to increase the transaction speed and reduce energy consumption. The QCG-ST system uses lattice-based encryption that is based on the Ring Learning With Errors (Ring-LWE) issue to protect itself from quantum assaults. It uses sharding, a Proof-of-Stake (PoS) consensus method, and a threshold signature scheme (TSS) to make the system more scalable and use less energy. Zero-knowledge proofs (ZKPs) are used to check transactions without giving out private information. We offer a cross-chain atomic swap protocol that uses hashed time-lock contracts to make sure that it works on all platforms. Blockchain transaction data utilized in testing originated from the Bitcoin Historical Dataset available on Kaggle, and quantum resistance has been assessed using the Qiskit Aer simulator. It evaluated the framework's performance to that of traditional methods like Payment Channel-Lightning Network (PC-LN), Variational Quantum Eigensolver (VQE), and Cross-Chain Transaction with Hyperledger (CCT-H). Results show that QCG-ST does far better than traditional systems in terms of transaction success rate (up to 98.5%), speed, energy efficiency, latency, and throughput, especially when tested in a quantum-simulated environment. This study completes in an essential vacuum in blockchain technology by suggesting a strong, quantum-resistant, privacy-protecting architecture that can handle the problems that could arise up in decentralized digital banking in the future.