The research of Quantum Key Distribution (QKD) has progressed apace in recent years, among which decoy QKD using an effective classical process to obtain secure key without perfect quantum devices has been largely concerned. In this article, an overview of decoy quantum key distribution is provided. We primarily focus on the model of implementing decoy idea, which mainly includes decoy devices at the source side and the detector side. Then related experimental realizations of decoy idea is introduced, and some defects remained to be solved are emphasized. Then, we discuss the future of decoy QKD and finally come to a conclusion.
The research of Quantum Key Distribution (QKD) has progressed apace in recent years, among which decoy QKD using an effective classical process to obtain secure key without perfect quantum devices has been largely concerned. In this article, an overview of decoy quantum key distribution is provided. We primarily focus on the model of implementing decoy idea, which mainly includes decoy devices at the source side and the detector side. Then related experimental realizations of decoy idea is introduced, and some defects remained to be solved are emphasized. Then, we discuss the future of decoy QKD and finally come to a conclusion.
Quantum Key Distribution (QKD) is an innovative technology which exploits the laws of quantum physics to generate and distribute shared secret key for use in cryptographic devices. Quantum Key Distribution offers the advantage of ‘unconditionally secure’ key generation with the unique ability to detect eavesdropping on the key distribution channel and shows promise for high-security applications such as those found in banking, government, and military environments. However, Quantum Key Distribution is a nascent technology where realized systems suffer from implementation non-idealities, which may significantly impact system performance and security. In this article, we discuss the modeling of a decoy state enabled Quantum Key Distribution system built to study the impact of these practical limitations. Specifically, we present a thorough background on the decoy state protocol, detailed discussion of the modeled decoy state enabled Quantum Key Distribution system, and evidence for component and sub-system verification, as well as, multiple examples of system-level validation. Additionally, we bring attention to practical considerations associated with implementing the decoy state protocol security condition gained from these research activities.
Quantum Key Distribution (QKD) supports the negotiation and sharing of private keys with unconditional security between authorized parties. Over the years, theoretical advances and experimental demonstrations have successfully transitioned QKD from laboratory research to commercial applications. As QKD expands its reach globally, it encounters challenges such as performance limitations, cost, and practical security concerns. Nonetheless, innovations in satellite-based QKD and the development of new protocols are paving the way towards a worldwide network. In this review, we provide an overview of QKD implementations, with a focus on protocols, devices, and quantum channels. We discuss the challenges of practical QKD and explore long-haul QKD. Additionally, we highlight the future research directions that are expected to significantly advance the realization of a global QKD network.
Due to the imperfect single photon source and the loss channel in real-life quantum key distribution systems,most current quantum communication experiments based on attenuated laser pulses are insecure under photon number splitting attack.Decoy state method,which is proposed as a useful and effective way to unconditionally secure quantum key distribution grounded on current technology,has become an important branch of quantum communication in recent years.Combined with the general model of quantum key distribution system,a comprehensive review is presented about typical schemes of decoy state method.Then the experimental research on decoy state method is reviewed briefly and the future direction is prospected in the end.
Quantum key distribution (QKD) is a straightforward cryptographic protocol for secure communication using quantum mechanics principles. This book chapter provides an introduction to QKD protocols based on theoretical principles, applicability, and recent advancements. The chapter provides an overview of the most popular BB84 protocol and its extensions, including measurement-device-independent QKD (MDI-QKD) and twin-field QKD (TF-QKD). The chapter includes continuous-variable QKD (CV-QKD) and its applicability to real networks. Security attacks, including side-channel attacks and photon-number splitting (PNS) attacks, are addressed with a focus on countermeasures, including decoy-state techniques and device-independent protocols. Application of QKD for network security, cloud computing, and critical infrastructure is addressed. Integration of QKD with classical cryptography techniques, post-quantum cryptography, and innovative quantum network topologies is addressed to investigate applicability for large-scale implementation. The chapter discusses recent advancements in superconducting nanowire single-photon detectors, quantum memory-assisted QKD, and free-space QKD in atmospheric channels. It also discusses innovative reconciliation techniques, authentication schemes, future developments, and deployment challenges and provides valuable information for researchers and practitioners.
It is a common belief that both the sender and receiver’s laboratory will be secured which will limit the feasibility of Quantum key distribution (QKD). Due to unavailability of a perfect single photon device, Eve can intercept the data during key generation process as well as distribution at sender’s laboratory. This imperfect photon source usually generates some multi-photons (decoy state) which create an open door for eavesdropping. These decoy states, which are more realistic than single photon states, are vulnerable using Photon Number Splitting Attack. This limitation in a long distance secure communication can be overcome by conceiving the idea of a perfect device independent protocol. This chapter deals with the various decoy state protocol methods and their limitations. The chronological developments of decoy state protocol for secure communication using various medium like fiber, free space, sea water, etc., has been discussed here.
To increase dramatically the distance and the secure key generation rate of quantum key distribution (QKD), the idea of quantum decoys--signals of different intensities--has recently been proposed. Here, we present the first experimental implementation of decoy state QKD. By making simple modifications to a commercial quantum key distribution system, we show that a secure key generation rate of 165 bit/s, which is 1/4 of the theoretical limit, can be obtained over 15 km of a telecommunication fiber. We also show that with the same experimental parameters, not even a single bit of secure key can be extracted with a non-decoy-state protocol. Compared to building single photon sources, decoy state QKD is a much simpler method for increasing the distance and key generation rate of unconditionally secure QKD.