A Novel Approach Based on Quantum Key Distribution Using BB84 and E91 Protocol for Resilient Encryption and Eavesdropper Detection

Aim:

        To implement a secure, interactive, and educational Quantum Key Distribution (QKD) system using the SARG04 algorithm simulated with Qiskit and deployed as a full-stack web application (Flask + React + MySQL) for demonstrating real-time quantum key sharing and eavesdropper detection between Alice, Bob, and Eve.

Abstract:

         Quantum cryptography provides unconditional security based on quantum mechanics. This project implements the SARG04 Quantum Key Distribution (QKD) protocol using Qiskit quantum simulation and demonstrates secure key sharing between Alice and Bob while detecting potential eavesdropping by Eve. The system allows users to visualize photon states, basis selection, measurement results, eavesdropping effects, and final key generation.To make the workflow accessible for learners and researchers, the quantum logic is integrated into a full-stack web interface using Flask (backend), React (frontend), and MySQL (database). Users can interactively run QKD operations, observe quantum state collapse, monitor QBER values, and understand how the SARG04 algorithm enhances security over BB84 against photon-number–splitting attacks.The proposed platform serves both as a research demonstration and as an educational tool, bridging theoretical quantum communication with a real-time web-based simulation.

Proposed System:

       The proposed system uses the SARG04 protocol, which modifies the classical communication step of BB84 by using non-orthogonal state pairs instead of basis revelation. This prevents an attacker from gaining information even if multiple photons exist in a pulse. The protocol retains the same four quantum states but changes how the information is disclosed, making state identification harder for an eavesdropper. This approach overcomes BB84’s PNS weakness and avoids E91’s complexity while maintaining strong quantum security.

Advantages:

      SARG04 offers higher security with practical photon sources, better resistance to PNS attacks, and no need for entanglement. It is simpler to implement than E91 and more secure than BB84 under real-world conditions. It provides a balanced combination of practicality, robustness, and improved resistance to realistic quantum attacks.