A theoretical model is under exploration towards the scope of developing a Quantum key distribution network. There is always a requirement of secured and confidential information processing so that the authentic and legitimate information one can get each time. Hence the quest for obtaining a perfect cypher continues. Considering the recent development in cryptography it was found that quantum mechanics exhibiting more solidarity when applied to cryptography and that generated a new dimension of secured information processing known as Quantum Cryptography. We propose a theoretical model of a network that will be used for quantum key distribution among users of the network as the extension of two-party E91 protocol for multiple users simultaneously. Applying the concept of parallel Hadamard transform with optical fiber channels gives us the platform of WDM multiplexing and de-multiplexing through the network.
A theoretical model is under exploration towards the scope of developing a Quantum key distribution network. There is always a requirement of secured and confidential information processing so that the authentic and legitimate information one can get each time. Hence the quest for obtaining a perfect cypher continues. Considering the recent development in cryptography it was found that quantum mechanics exhibiting more solidarity when applied to cryptography and that generated a new dimension of secured information processing known as Quantum Cryptography. We propose a theoretical model of a network that will be used for quantum key distribution among users of the network as the extension of two-party E91 protocol for multiple users simultaneously. Applying the concept of parallel Hadamard transform with optical fiber channels gives us the platform of WDM multiplexing and de-multiplexing through the network.
Quantum cryptography, exclusively known as Quantum key distribution (QKD), has attracted a lot of attention in the recent years with the discovery that it can provide absolute secrecy for communications.We report a new architecture for constructing a fiber-based network of quantum key distribution using optical wavelength division multiplexing in the fiber, and also using some wavelength protocols.The advantages are discussed in detail for demonstrating the experimental report in the way of feasibility for the proposed architecture.
Quantum Cryptography (QC) is the emerging field of the current world and the potential player of the future. Quantum Key Distribution (QKD) is the matured discipline of QC and available in the market to establish a secret key between parties. In order to achieve in multiparty, basically quantum entanglement has been applied over a theoretical settings. However, due to practical limitation, entanglement based research has a feasible difficulty with current technology. The thesis principal goal is to propose a framework for quantum protocol layer for secure key management without entanglement over multiparty environment. In the secret key management, conference key or Multiparty QKD (MQKD) and joint-venture key or Public Shared Secret Quantum Key (PSSQK) protocols acted as a top layer and quantum user authentication scheme as a middle layer and the standard QKD operation as a bottom layer. The proposed secrete key management protocols are based on secret key between parties using QKD, modified error correction code and linear independent matrix. These protocols require only classical communication and yield higher secret key rate regardless of distance and noise. The security analysis using guessing entropy has applied and results shows only negligible amount information can be extracted during eavesdropping. The challenge-challenge response technique has been applied to proposed quantum user authentication scheme for verification of quantum user. This is a bidirectional authentication scheme and requires both quantum and classical channel to execute and has two modes of operation, i.e., initial and session authentication.Due to deterministic key distribution orientation, the efficiency of protocol reaches up to 100% in terms of reduction of photon wastage during communication. Further, this scheme is resilient to various quantum security attacks However, this scheme requires noiseless quantum channel in order to detect the insider and outsider attacks during authentication. A GUI based discrete event simulation has developed using OptiSystem™ in order to test the practical feasibility of proposed quantum cryptography protocol layer. The polarized based discrete variable QKD protocols have been designed and analyzed. Due to lack of real receiver setup, the results have showed lower quantum bit error rate. Further, we analyzed the impact of polarization structure of qubit due to noise, loss and distance over fiber optics and free space. A multiparty QKD setuphas been designed based on frequency division multiplexing (FDM) centralized quantum channel server. This approach reduces the requirement of total quantum channel from N*(N-1)/2 to N and each party requires one quantum channel to communicate with all other parties. The bit commitment protocol and message authentication in the layer has considered for the future research direction.
Quantum cryptography applies the uncertainty principle and the no-cloning theorem of quantum mechanics to provide ultra-secure encryption key distribution between two parties. Present quantum cryptography technologies provide encryption key distribution between two parties. However, practical implementations encryption key distribution schemes require establishing secure quantum communications amongst multiple users. In this talk, we survey some of the state of the art quantum encryption deployment in communication networks. We will also discuss some common topologies that are being considered for multi-user quantum encryption networks. The performance of the multi-user quantum key distribution systems is then compared for four different optical network topologies: the Sagnac-based fiber ring, the wavelength routed, the passive star and the bus network. Their performances are compared and analyzed using quantum bit error rate analysis.
Quantum Key Distribution (QKD) provides promising secure communication, the crucial need for online security in Public Key Infrastructure (PKI). QKD is mainly used for distribution of keys securely between two parties and is a commercially available application of Quantum Cryptography (QC). QKD has the ability to enable the authenticated users to detect unwanted attempts by the intruder in trying to gain knowledge of the secret key. Through the fundamental nature of quantum mechanics, in Principle QKD has the distinction of being, unshakable. Quantum cryptography harnesses the counterintuitive behavior of elementary particles such as photons and ensures the confidentiality of information transmitted between two parties. There are many QKD protocols that provide a secure key which include BB84 protocol, BB92 protocol, SARG04 protocol, E91 protocol, COW protocol, DPS protocol ect. In this review the trends and challenges in Quantum Key Distribution is discussed. Also the contribution of QKD towards network security is presented by analyzing its strengths and weakness.
Quantum Key Distribution (QKD) exploits the rules of quantum mechanics to generate and securely distribute a random sequence of bits to two spatially separated clients. Typically a QKD system can support only a single pair of clients at a time, and so a separate quantum link is required for every pair of users. We overcome this limitation with the design and characterization of a multi-client entangled-photon QKD system with the capacity for up to 100 clients simultaneously. The time-bin entangled QKD system includes a broadband down-conversion source with two unique features that enable the multi-user capability. First, the photons are emitted across a very large portion of the telecom spectrum. Second, and more importantly, the photons are strongly correlated in their energy degree of freedom. Using standard wavelength division multiplexing (WDM) hardware, the photons can be routed to different parties on a quantum communication network, while the strong spectral correlations ensure that each client is linked only to the client receiving the conjugate wavelength. In this way, a single down-conversion source can support dozens of channels simultaneously--and to the extent that the WDM hardware can send different spectral channels to different clients, the system can support multiple client pairings. We will describe the design and characterization of the down-conversion source, as well as the client stations, which must be tunable across the emission spectrum.
With the rapid development of high-security applications such as finance, cloud computing, and key government services, network security issues have become increasingly prominent. Against this backdrop, quantum key distribution (QKD) technology has emerged as an important solution to address the security challenges of optical networks. Based on the principles of quantum mechanics, this technology can achieve unbreakable key distribution during communication, providing intrinsic security for the exchange of confidential information. It is currently one of the most promising long-term security protection technologies for optical networks.Due to the high cost of independently deploying quantum communication networks, integrating quantum channels with classical optical networks for transmission has become the most feasible solution at present. Meanwhile, the continuous development of technologies such as high-order modulation and wavelength division multiplexing has brought the transmission capacity of conventional single-mode fibers close to their theoretical Shannon limit, and mode division multiplexing(MDM) can effectively solve the problem of transmission capacity.However, quantum signals are highly susceptible to crosstalk caused by classical signals during the simultaneous transmission with classical signals. This paper conducts a simulation experiment on a quantum-classical fusion system based on MDM. The results show that the quantum signals are not significantly interfered with by the classical signals during simultaneous transmission, and this system is suitable as a simultaneous transmission scheme for large-scale networking of quantum secure communication.