Quantum secured blockchain framework for enhancing post quantum data security.

Area of Science:

• Cybersecurity
• Quantum Computing
• Blockchain Technology

Background:

• Classical cryptographic primitives (RSA, ECDSA, SHA-256) are vulnerable to quantum algorithms like Shor's and Grover's.
• Existing blockchain security strategies often address isolated components, lacking end-to-end quantum threat protection.
• Traditional consensus mechanisms (Proof-of-Work, Proof-of-Stake) face amplified vulnerabilities with quantum adversaries.

Purpose of the Study:

• To introduce QuantumShield-BC, a comprehensive blockchain framework designed to counter quantum computing threats.
• To integrate post-quantum cryptography, quantum key distribution (QKD), and a novel quantum consensus mechanism (Q-BFT).
• To ensure end-to-end security, scalability, and performance for blockchain networks in a post-quantum era.

Main Methods:

• Implementation of post-quantum cryptographic signatures for secure transaction signing.
• Integration of quantum key distribution (QKD) for tamper-proof key exchange.
• Development of a Quantum Byzantine Fault Tolerance (Q-BFT) consensus mechanism utilizing quantum random number generation (QRNG).

Main Results:

• QuantumShield-BC demonstrates perfect security against simulated Shor's and Grover's algorithm attacks.
• The framework achieves 0% Sybil attack effectiveness, eliminating replay and man-in-the-middle (MITM) vulnerabilities.
• Experimental results show high throughput (>7,000 TPS with 100 validators) and low consensus latency.

Conclusions:

• QuantumShield-BC provides a robust, modular, and future-proof blockchain solution against quantum threats.
• The framework is suitable for critical infrastructure and digital trust ecosystems requiring high assurance and scalability.
• QuantumShield-BC offers a practical, high-performance, and interoperable post-quantum blockchain framework.