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IEEE International Conference on Computing, Applications and Systems (COMPAS)

Simulation of E91 Quantum Key Distribution Protocol Using Qiskit

Naheen Mohd. Kadir, Md. Ali Hossain

Published Oct 23, 2025• 0 citations
Publisher

Abstract

We use the Qiskit quantum computing framework to simulate the E91 Quantum Key Distribution (QKD) protocol. By measuring entangled photon pairs, the E91 protocol uses quantum entanglement to safely transfer cryptographic keys between Alice and Bob. In order to investigate the key generation rates, Bell’s inequality violation, and the protocol’s resilience to eavesdropping, we simulate the protocol in this work using IBM’s quantum simulator. The findings demonstrate that the E91 protocol may effectively create a secure key by taking advantage of quantum entanglement and identifying any eavesdropping attempts by breaking Bell’s inequality, with a calculated Bell’s parameter of S = 2.47, exceeding the classical limit which is 2. Additionally, key extraction is shown to be possible by the analysis of measurement results, where the key creation rate improves with the number of entangled particles, achieving a key generation rate of 1.59 bps for 25 singlet states, 5.37 bps for 100 singlet states, 10.52 bps for 250 singlet states, and 12.24 bps for 500 singlet states, with corresponding key lengths of 7, 25, 57, and 106 bits, respectively.

DOI
10.1109/compas67506.2025.11381830

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We use the Qiskit quantum computing framework to simulate the E91 Quantum Key Distribution (QKD) protocol. By measuring entangled photon pairs, the E91 protocol uses quantum entanglement to safely transfer cryptographic keys between Alice and Bob. In order to investigate the key generation rates, Bell’s inequality violation, and the protocol’s resilience to eavesdropping, we simulate the protocol in this work using IBM’s quantum simulator. The findings demonstrate that the E91 protocol may effectively create a secure key by taking advantage of quantum entanglement and identifying any eavesdropping attempts by breaking Bell’s inequality, with a calculated Bell’s parameter of S = 2.47, exceeding the classical limit which is 2. Additionally, key extraction is shown to be possible by the analysis of measurement results, where the key creation rate improves with the number of entangled particles, achieving a key generation rate of 1.59 bps for 25 singlet states, 5.37 bps for 100 singlet states, 10.52 bps for 250 singlet states, and 12.24 bps for 500 singlet states, with corresponding key lengths of 7, 25, 57, and 106 bits, respectively.
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