A Blockchain-Assisted Fair Exchange Signature Protocol Using Quantum Key Distribution for Metaverse Environment

The metaverse has profoundly altered the conventional online landscape and has attracted significant interest from researchers and industry professionals. As the metaverse changes quickly, it needs strong and safe cryptographic solutions to make sure that transactions are fair and safe in its highly connected world. This paper presents a novel blockchain-assisted fair exchange signature protocol leveraging quantum key distribution (QKD) to ensure security against both classical and quantum adversaries. The suggested protocol combines blockchain technology with quantum key distribution to create an exchange framework that can’t be changed, is clear, and can’t be tampered with. It also uses quantum mechanics to create keys that are always safe. By incorporating a fair exchange mechanism, the protocol guarantees that either both parties fulfill their obligations or neither party benefits, addressing trust issues in decentralized metaverse transactions. Furthermore, we provide a detailed analysis of the protocol’s security, efficiency, and scalability, highlighting its resistance to quantum attacks and its suitability for real-time applications in the metaverse. Simulation results demonstrate that the protocol significantly enhances exchange fairness, minimizes latency, and ensures robust authentication, making it a promising candidate for securing transactions in next-generation digital ecosystems. Web 3.0 technologies provide a resolution by facilitating a decentralized metaverse ecology. The suggested protocol utilizes quantum fundamentals to facilitate safe communication, while the incorporation of quantum cryptography with Web 3.0 improves the efficiency, security, and authenticity of metaverse environments. We test the proposed quantum signature scheme both theoretically and practically using QuantumSim simulations, demonstrating strong signature performance in comparison to other schemes. The results indicate a computational cost of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.815 ms$ </tex-math></inline-formula>, and communication costs of 1312 bits, demonstrating the protocol’s resilience and performance by conducting a thorough safety and efficiency analysis and demonstrating compliance with essential security features, including unforgeability, undeniability, verifiability, and traceability.