Publications From Our Labs

DOP- 10/11/2021 Journal- International Journal of Theoretical Physics Abstract- In this paper, we propose a new theoretical scheme for quantum secure direct communication (QSDC) with user authentication. Different from the previous QSDC protocols, the present protocol uses only one orthogonal basis of single-qubit states to encode the secret message. Moreover, this is a one-time and one-way communication protocol, which uses qubits prepared in a randomly chosen arbitrary basis, to transmit the secret message. We discuss the security of the proposed protocol against some common attacks and show that no eavesdropper can get any information from the quantum and classical channels. We have also studied the performance of this protocol under realistic device noise. We have executed the protocol in IBMQ Armonk device and proposed a repetition code-based protection scheme that requires minimal overhead.

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DOP- 26/07/2022 Journal- Quantum Information Processing Abstract- Quantum secure direct communication (QSDC) and deterministic secure quantum communication (DSQC) are two important branches of quantum cryptography, where one can transmit a secret message securely without encrypting it by a prior key. In the practical scenario, an adversary can apply detector-side-channel attacks to get some non-negligible amount of information about the secret message. Measurement-device-independent (MDI) quantum protocols can remove this kind of detector-side-channel attack, by introducing an untrusted third party (UTP), who performs all the measurements during the protocol with imperfect measurement devices. In this paper, we put forward the first MDI-QSDC protocol with user identity authentication, where both the sender and the receiver first check the authenticity of the other party and then exchange the secret message. Then we extend this to an MDI quantum dialogue (QD) protocol, where both the parties can send their respective secret messages after verifying the identity of the other party. Along with this, we also report the first MDI-DSQC protocol with user identity authentication. Theoretical analyses prove the security of our proposed protocols against common attacks.
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DOP- 01/01/2021 Journal- Quantum Information and computation Abstract- Quantum conference is a proces s of securely exchanging messages between three or more parties, using quantum resources. A Measurement Device Independent Quantum Dialogue (MDI-QD) protocol, which is secure against information leakage, has been proposed (Quantum Information Processing 16.12 (2017): 305) in 2017, is proven to be insecure against intercept-and-resend attack strategy. We first modify this protocol and generalize this MDI-QD to a three-party quantum conference and then to a multi-party quantum conference. We also propose a protocol for quantum multi-party XOR computation. None of these three protocols proposed here use entanglement as a resource and we prove the correctness and security of our proposed protocols.

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DOP- 11/11/2022 Journal- IEEE Xplore Abstract- An important idea in quantum networks is that of employing virtual edges or “short-cuts” between quantum nodes. These edges, which are shared entangled pairs between two nodes that are not directly connected “physically”, are expected to reduce the average latency of entanglement distribution in quantum network routing. In this work, we show how to create such edges on an existing discrete event simulator for quantum networks called SeQUeNCe and study the impact that these edges have on latency. Additionally, we implement a distributed routing algorithm on the simulator and demonstrate its use in conjunction with the virtual edges. We observe a reduction in latency when short cuts are used, as is expected. Thus, with these modifications, we believe that SeQUeNCe (and other similar simulators) can be used for experimenting with advanced quantum networking protocols.

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DOP- 11/11/2022 Journal- IEEE Xplore Abstract- Quantum routing protocols seek to distribute entanglement across different nodes of a quantum network. A recently popular approach for quantum routing is to cut down the latency times for sharing entanglement by using virtual edges in addition to physical ones. While a physical edge is associated with the presence of a quantum channel, virtual edges correspond to pre-existing entanglement between some nodes which can be leveraged for entanglement swapping. Distributed routing protocols for quantum networks have been proposed and analyzed using this idea. These analyses have also been backed up by simulations. However, to the best of our knowledge, existing simulation approaches consider a static picture, where the demands for entangled pairs are presented upfront. In this paper, we study routing algorithms through time-driven simulations. Such an approach allows for the demands to emerge in real-time as the simulation proceeds, and therefore mimic realistic scenarios better. This also facilitates studying routing protocols in the presence of dynamic replenishment of entangled pairs and exposes issues like occurrence of deadlocks in the context of limited quantum resources. As a demonstration of the approach, we show simulation results that analyze the performance of various physical and virtual graph topologies in terms of average latency time. Finally, we show the change in performance and network saturation in the presence of replenishment of entanglement resources.

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