Decentralized Quantum Networks: Challenges and Solutions

B. Prajwal, A. Asha Kumari, E. Saravana Kumar

K. Kalaiselvi, A. Bhuvaneswari, Ravi Srivel +3 more

S. Rajkumar, K. Kavitha

Quantum networks promise unparalleled security benefits, leveraging the principles of quantum mechanics for secure communication. However, practical challenges, such as key distribution and authentication, remain pivotal concerns. Blockchain technology, with its decentralized and immutable nature, provides a compelling solution for enhancing the security of quantum networks. This review paper explores the integration of blockchain with quantum networks, highlighting its role in secure key distribution and authentication mechanisms. We examine existing models, challenges, and future directions in the field, offering insights into how blockchain can fortify quantum communication networks against emerging threats.

Juan Carlos Boschero, Niels M. P. Neumann, Ward van der Schoot +2 more

Jian Li, Zheng Peng, Zhonghui Li +4 more

In recent years, multi-hop Quantum Key Distribution (QKD) network has been proven as a promising solution through rigorous practices to provide end-to-end key exchange service for arbitrary communication parties. However, existing decentralized solutions still face critical challenges including consistency and fairness that stem from storable nature of quantum key material. Thus, in this paper, we first devise a Key Management and Service (KM&S) framework for decentralized multi-hop QKD networks, which provides functional decoupling and pipeline processing to guarantee flexibility and compatibility for practical implementation. After that, to address consistency and fairness challenges during end-to-end key exchange service, we focus on two aspects including local key management and end-to-end congestion control, and respectively propose an elastic key supply rate control scheme named AUTO and a Capacity Probing-driven Backpressure Flow Control (CP-BFC) scheme. Furthermore, we construct an experiment platform equipped with realistic QKD devices based on China metropolitan QKD network topology to implement the proposed framework and schemes, and conduct extensive experiments compared to representative schemes in existing studies. The experimental results show that AUTO&CP-BFC significantly outperforms representative schemes in terms of consistency and fairness.

Woonghee Lee, Dong-Hee Kim, Junbeom Hur

While the quantum Internet leverages quantum mechanics to achieve unprecedented security against security threats such as eavesdropping, challenges remain, particularly in trust establishment. Traditional methods using a trusted third party in the conventional Internet system may be inadequate in decentralized or ad-hoc networks. Whereas, blockchain technology offers a decentralized solution, making it a promising solution. However, no studies have been conducted to evaluate the blockchain consensus protocols in diverse quantum Internet scenarios. This study assesses the-state-of-art Byzantine Fault Tolerance consensus protocol, ParBFT, with regard to the scal-ability and resilience through the quantum Internet simulation. Moreover, this study explores the potential enhancement to better meet the unique demands of high-latency or unstable networks.