[Paper Review] Measurement-device-independent QSDC protocol using Bell and GHZ states on quantum simulator

Arunaday Gupta, Bikash K. Behera+1 more|arXiv (Cornell University)|Jul 1, 2020

Quantum Information and Cryptography21 references4 citations

TL;DR

This paper proposes a measurement-device-independent quantum secure direct communication (MDI-QSDC) protocol using Bell and GHZ entangled states, implemented on the IBM Quantum Experience platform. By leveraging entanglement swapping and a third-party measurement model, the protocol ensures security against measurement-device attacks and enables direct transmission of secret messages without key distribution, validated through quantum circuit simulations and inner product-based eavesdropping detection.

ABSTRACT

Secure cryptographic protocols are indispensable for modern communication systems. It is realized through an encryption process in cryptography. In quantum cryptography, Quantum Key Distribution (QKD) is a widely popular quantum communication scheme that enables two parties to establish a shared secret key that can be used to encrypt and decrypt messages. But security loopholes still exist in this cryptographic protocol, as an eavesdropper can in principle still intercept all the ciphertext to perform cryptanalysis and the key may get leaked to the eavesdropper, although it happens very rarely. However, there exists a more secure quantum cryptographic scheme known as Quantum Secure Direct Communication (QSDC) protocol that eliminates the necessity of key, encryption and ciphertext transmission. It is a unique quantum communication scheme where secret information is transmitted directly over a quantum communication channel. We make use of measurement-device-independent (MDI) protocol in this scheme where all the measurements of quantum states during communication are performed by a third party that can be untrusted or even an eavesdropper. This eliminates all loopholes in practical measurement devices. Here, we realize this MDI-QSDC protocol using Bell and GHZ states in the IBM Quantum Experience platform and implement swapping circuits for security check.

Motivation & Objective

• To develop a secure quantum communication protocol that eliminates the need for key distribution and ciphertext transmission.
• To address security vulnerabilities in practical quantum communication systems caused by measurement-device imperfections.
• To implement a measurement-device-independent (MDI) QSDC protocol using Bell and GHZ entangled states on a real quantum platform.
• To validate the protocol’s security through quantum circuit simulations and inner product-based eavesdropping detection.
• To demonstrate the feasibility of direct, secure message transmission using entanglement swapping and superdense coding on the IBM Quantum Experience.

Proposed method

• The protocol uses Bell and GHZ states as entangled resource states for secure communication between Alice and Bob.
• Entanglement swapping is applied via Bell basis measurements on a third party (Charlie), entangling Alice’s and Bob’s qubits.
• A swapping circuit is implemented to compute the inner product between initial and final quantum states, detecting eavesdropping attempts.
• Z-gate operations are applied on Alice’s qubits to encode messages, enabling superdense coding for direct transmission.
• GHZ basis measurements are performed by Charlie on the third-party qubits to collapse the state and reveal the encoded message.
• The protocol is simulated on the IBM Quantum Experience platform using real quantum circuits and histogram-based state verification.

Experimental results

Research questions

• RQ1 Can a measurement-device-independent QSDC protocol be effectively implemented using Bell and GHZ entangled states on a real quantum platform?
• RQ2 How can entanglement swapping be used to securely link remote qubits in a device-independent manner?
• RQ3 Can inner product-based swapping circuits reliably detect eavesdropping in a practical QSDC setup?
• RQ4 To what extent does the protocol maintain security against measurement-device attacks in a simulated environment?
• RQ5 How can superdense coding be integrated into the MDI-QSDC framework for direct message transmission?

Key findings

• The MDI-QSDC protocol successfully enables direct, secure transmission of secret messages without key distribution or ciphertext.
• Entanglement swapping between Bell and GHZ states results in remote entanglement between Alice and Bob, verified through quantum circuit simulations.
• The inner product calculation via swapping circuits effectively detects eavesdropping attempts, with results indicating no significant deviation when no eavesdropping occurs.
• Histogram plots from the IBM Quantum Experience confirm that Bob correctly decodes messages sent via superdense coding, validating the protocol’s functionality.
• The protocol demonstrates immunity to measurement-device attacks by delegating all measurements to an untrusted third party (Charlie).
• The implementation on IBM Quantum Experience confirms the feasibility of MDI-QSDC using standard quantum gates and measurement protocols.