Quantum key distribution (QKD) is a technology for distributing cryptographic keys between two communication parties based on the quantum physics for the secure communication. A trusted nodebased key relay technique is integrated with QKD to overcome the technical limitations of QKD and to enable key distribution between two arbitrary communication parties in the trusted node network, which we refer to as the QKD network. In addition, secret sharing technology has been integrated with the QKD network to realize secure data storage and secure data communication, which we call a quantum secure cloud. This paper presents the development and evaluation of the proof-of-concept (PoC) system for the QKD network and quantum secure cloud, specially applied to the genome medicine domain. The PoC system was developed at Tohoku University and Toshiba sites to address the “cancer clinical sequencing” use-case. We evaluated three practical scenarios with the PoC system: (1) real-time transmission of genome analysis data, (2) “expert panel”, an online video conference for medical experts' discussion, and (3) distributed backup of genome analysis data. To support these scenarios, we developed three new functions: (1) a function for monitoring output data and pipeline processing of data encryption/decryption and transmission for secure large-scale data transfer, (2) a key management system function to achieve both large-scale data transmission and low-latency data communication, and (3) a function for preemptive key data reading and direct access to storage devices to enable high-speed data transmission and distributed data backup using a secret sharing scheme. These scenarios and functions were evaluated and demonstrated using real or simulated genome data. The evaluation results reveal that QKD network and quantum secure cloud technologies can be applied to cancer clinical sequencing as a use-case of the genome medicine domain.
Quantum key distribution (QKD) is a technology for distributing cryptographic keys between two communication parties based on the quantum physics for the secure communication. A trusted nodebased key relay technique is integrated with QKD to overcome the technical limitations of QKD and to enable key distribution between two arbitrary communication parties in the trusted node network, which we refer to as the QKD network. In addition, secret sharing technology has been integrated with the QKD network to realize secure data storage and secure data communication, which we call a quantum secure cloud. This paper presents the development and evaluation of the proof-of-concept (PoC) system for the QKD network and quantum secure cloud, specially applied to the genome medicine domain. The PoC system was developed at Tohoku University and Toshiba sites to address the “cancer clinical sequencing” use-case. We evaluated three practical scenarios with the PoC system: (1) real-time transmission of genome analysis data, (2) “expert panel”, an online video conference for medical experts' discussion, and (3) distributed backup of genome analysis data. To support these scenarios, we developed three new functions: (1) a function for monitoring output data and pipeline processing of data encryption/decryption and transmission for secure large-scale data transfer, (2) a key management system function to achieve both large-scale data transmission and low-latency data communication, and (3) a function for preemptive key data reading and direct access to storage devices to enable high-speed data transmission and distributed data backup using a secret sharing scheme. These scenarios and functions were evaluated and demonstrated using real or simulated genome data. The evaluation results reveal that QKD network and quantum secure cloud technologies can be applied to cancer clinical sequencing as a use-case of the genome medicine domain.
Secure storage and secondary use of individual human genome data is increasingly important for genome research and personalized medicine. Currently, it is necessary to store the whole genome sequencing information (FASTQ data), which enables detections of de novo mutations and structural variations in the analysis of hereditary diseases and cancer. Furthermore, bioinformatics tools to analyze FASTQ data are frequently updated to improve the precision and recall of detected variants. However, existing secure secondary use of data, such as multi-party computation or homomorphic encryption, can handle only a limited algorithms and usually requires huge computational resources. Here, we developed a high-performance one-stop system for large-scale genome data analysis with secure secondary use of the data by the data owner and multiple users with different levels of data access control. Our quantum secure cloud system is a distributed secure genomic data analysis system (DSGD) with a "trusted server" built on a quantum secure cloud, the information-theoretically secure Tokyo QKD Network. The trusted server will be capable of deploying and running a variety of sequencing analysis hardware, such as GPUs and FPGAs, as well as CPU-based software. We demonstrated that DSGD achieved comparable throughput with and without encryption on the trusted server Therefore, our system is ready to be installed at research institutes and hospitals that make diagnoses based on whole genome sequencing on a daily basis.
Abstract Supercomputers, quantum computers, other computers, and algorithmic advancements that can break cryptographic systems currently in use are becoming a reality. For information that requires long-term confidentiality (e.g. national security, military security, genomic data etc.), the threat of eavesdropping must be seriously considered. The leakage of such information would not only cause temporary confusion but would also have serious repercussions for future generations. Part of such important data are already being exchanged over the Internet using cryptography that is not resistant to quantum computers. Considering the possibility of harvest attacks on information that must be kept secret for centuries, developing a technology that can immediately eliminate the risk of eavesdropping in principle is desirable. In response to these demands, we previously developed an information-theoretically secure method for data transmission, storage, recovery, and authentication with a single password using a quantum key distribution network called a quantum secure cloud. We now apply this technology to develop an information-theoretically secure long-distance data-relay function and succeed in developing a distributed data-relay simulator that is compatible with current quantum key distribution networks. The throughput of this protocol is more than 10 Mbps for 10 MB data, so it can be applied to practical use.
Quantum key distribution (QKD), a cryptography technology providing information theoretic security based on physical laws, has moved from the research stage to the engineering stage. Although the communication distance is subject to a limitation attributable to the QKD fundamentals, recent research and development of “key relaying” over a “QKD network” is overcoming this limitation. However, there are still barriers to widespread use of QKD integrated with conventional information systems: applicability and development cost. In order to break down these barriers, this paper proposes a new solution for developing secure network infrastructure based on QKD technology to accommodate multiple applications. The proposed solution introduces 3 functions: (1) a directory mechanism to manage multiple applications hosted on the QKD network, (2) a key management method to share and to allocate the keys for multiple applications, and (3) a cryptography communication library enabling existing cryptographic communication software to be ported to the QKD network easily. The proposed solution allows the QKD network to accommodate multiple applications of various types, and moreover, realizes applicability to conventional information systems easily. It also contributes to a reduction in the development cost per information system, since the development cost of the QKD network can be shared between the multiple applications. The proposed solution was implemented with a network emulating QKD technology and evaluated. The evaluation results show that the proposed solution enables the infrastructure of a single QKD network to host multiple applications concurrently, fairly, and effectively through a conventional application programming interface, OpenSSL API. In addition, the overhead of secure session establishment by the proposed solution was quantitatively evaluated and compared.
Secure communication makes the widespread use of telecommunication networks and services possible. With the constant progress of computing and mathematics, new cryptographic methods are being diligently developed. Quantum Key Distribution (QKD) is a promising technology that provides an Information-Theoretically Secure (ITS) solution to the secret-key agreement problem between two remote parties. QKD networks based on trusted relay nodes are built to provide service to a larger number of parties at arbitrary distances. They function as an add-on technology to traditional networks, generating, managing, distributing, and supplying ITS cryptographic keys. Since key resources are limited, integrating QKD network services into critical infrastructures necessitates effective key management. As a result, this article provides a comprehensive review of key management approaches for trusted-relay QKD networks. They are analyzed to facilitate the identification of potential strategies and accelerate the future development of QKD networks.
The increasing reliance on optical communication networks for high-speed data transmission has amplified concerns regarding secure information exchange in the era of quantum computing. Classical cryptographic protocols such as RSA and ECC, though widely deployed, are vulnerable to attacks from large-scale quantum computers executing Shor’s algorithm. Quantum Key Distribution (QKD) has emerged as a revolutionary cryptographic paradigm that leverages the principles of quantum mechanics to enable theoretically unbreakable key exchange. This paper investigates the integration of QKD into optical communication networks, focusing on protocol design, implementation challenges, and potential scalability. Through scenario-based evaluation, the study highlights the trade-offs between quantum security and practical deployment constraints such as channel loss, photon detector efficiency, and key generation rates. Results from simulated models demonstrate that while QKD can achieve provable security in metropolitan-area networks, long-distance transmission requires advanced techniques such as quantum repeaters and trusted nodes. This work concludes that QKD offers a promising pathway toward quantum-safe communication but necessitates
We propose a secure and scalable file-encryption scheme for cloud systems by integrating Post-Quantum Cryptography (PQC), Quantum Key Distribution (QKD), and Advanced Encryption Standard (AES) within a distributed architecture. While prior studies have primarily focused on secure key exchange or authentication protocols (e.g., layered PQC-QKD key distribution), our scheme extends beyond key management by implementing a distributed encryption architecture that protects large-scale files through integrated PQC, QKD, and AES. To support high-throughput encryption, our proposed scheme partitions the target file into fixed-size subsets and distributes them across slave nodes, each performing parallel AES encryption using a locally reconstructed key from a PQC ciphertext. Each slave node receives a PQC ciphertext that encapsulates the AES key, along with a PQC secret key masked using QKD based on the BB84 protocol, both of which are centrally generated and managed by the master node for secure coordination. In addition, an encryption and transmission pipeline is designed to overlap I/O, encryption, and communication, thereby reducing idle time and improving resource utilization. The master node performs centralized decryption by collecting encrypted subsets, recovering the AES key, and executing decryption in parallel. Our evaluation using a real-world medical dataset shows that the proposed scheme achieves up to 2.37× speedup in end-to-end runtime and up to 8.11× speedup in encryption time over AES (Original). In addition to performance gains, our proposed scheme maintains low communication cost, stable CPU utilization across distributed nodes, and negligible overhead from quantum key management.