Efficient Quantum Key Distribution Using Balanced Incomplete Block Designs

Quantum Key Distribution (QKD) is a critical technology for secure communication in the quantum era, with the BB84 protocol being one of the most widely adopted methods for sharing secret keys. However, random qubit distribution in the BB84 protocol presents challenges, such as inefficient qubit usage, higher error rates, and potential security vulnerabilities. This paper introduces a Efficient Quantum Key Distribution Using Balanced Incomplete Block Designs (BIBD) to optimize qubit distribution. By leveraging BIBD properties, the scheme achieves more efficient and balanced qubit allocation, enhancing security by increasing the key generation rate and improving resistance to eavesdropping attacks. Theoretical analysis and simulation results show that this scheme enhances scalability and key generation rates while maintaining robust security guarantees, making it suitable for large-scale quantum communication systems.