The Quantum Cryptography Approach: Unleashing the Potential of Quantum Key Reconciliation Protocol for Secure Communication

TL;DR

The paper addresses secure quantum key distribution under device imperfections by introducing a non-leaking key verification method based on polynomial interpolation, enabling Eve detection without exposing key material. It modifies BB84 so that only Alice reveals the relevant encoding basis, and uses set generation and polynomial interpolation to verify and reconcile keys while avoiding information leakage. The approach is implemented and evaluated on IBMQ backends (45-qubit target; 7-qubit demonstration in simulation) and analyzed under Pauli, depolarizing, and measurement noise, showing robustness and a nonzero key-generation probability even at high noise. The results advance practical QKD by reducing leakage, enabling reliable key verification, and highlighting performance under realistic noise models, with potential for deployment in integrated quantum networks.

Abstract

Quantum cryptography is the study of delivering secret communications across a quantum channel. Recently, Quantum Key Distribution (QKD) has been recognized as the most important breakthrough in quantum cryptography. This process facilitates two distant parties to share secure communications based on physical laws. The BB84 protocol was developed in 1984 and remains the most widely used among BB92, Ekert91, COW, and SARG04 protocols. However the practical security of QKD with imperfect devices have been widely discussed, and there are many ways to guarantee that generated key by QKD still provides unconditional security. This paper proposed a novel method that allows users to communicate while generating the secure keys as well as securing the transmission without any leakage of the data. In this approach sender will never reveal her basis, hence neither the receiver nor the intruder will get knowledge of the fundamental basis.Further to detect Eve, polynomial interpolation is also used as a key verification technique. In order to fully utilize the quantum computing capabilities provided by IBM quantum computers, the protocol is executed using the Qiskit backend for 45 qubits. This article discusses a plot of % error against alpha (strength of eavesdropping). As a result, different types of noise have been included, and the success probability of the desired key bits has been determined. Furthermore, the success probability under depolarizing noise is explained for different qubit counts.Last but not least, even when the applied noise is increased to maximum capacity, a 50% probability of successful key generation is still observed in an experiment.

Figures (13)

• Figure 1: The proposed methodology is an appropriate technique for both the sender and receiver sides to generate safe secret keys
• Figure 2: Set Generation for key verification
• Figure 3: Arrangement of $4*N$ bits in $M$ rows and m columns after set generation where each row has $s$ no. of chunks each containing $n$ bits
• Figure 4: Random selection of indices for the equation generation
• Figure 5: Alice randomly generating her bits and her encoding bases