We introduce a new integral method for Quantum Key Distribution to perform sifting, reconciliation and amplification processes to establish a cryptographic key through the use of binary structures called frames which are capable to increase quadratically the secret key rate. The method can be implemented with the usual optical Bennett-Brassard (BB84) equipment allowing strong pulses in the quantum regime.
We introduce a new integral method for Quantum Key Distribution to perform sifting, reconciliation and amplification processes to establish a cryptographic key through the use of binary structures called frames which are capable to increase quadratically the secret key rate. The method can be implemented with the usual optical Bennett-Brassard (BB84) equipment allowing strong pulses in the quantum regime.
We present an error reconciliation method for Quantum Key Distribution (QKD) that corrects 100% of errors generated in regular binary frames transmitted over a noisy quantum channel regardless of the quantum channel error rate. In a previous investigation, we introduced a novel distillation QKD algorithm whose secret key rate descends linearly with respect to the channel error rate. Now, as the main achievement of this work, we demonstrate an improved algorithm capable of retaining almost all the secret information enclosed in the regular binary frames. Remarkably, this technique increases quadratically the secret key rate as a function of the double matching detection events and doubly quadratically in the number of the quantum pulses. Furthermore, this reconciliation method opens up the opportunity to use less attenuated quantum pulses, would allow greater QKD distances at drastically increased secret key rate. Since our method can be implemented as a software update, we hope that quantum key distribution technology would be fast deployed over global data networks in the quantum era.
Quantum cryptography is a paradigm for the establishment of secret keys and data confidentiality, which represents an alternative in the quantum era because its security properties are based on the principles of quantum physics. Unfortunately, errors that occur during transmission and detection of quantum states have made it difficult to implement this technology globally. However, a new cryptographic key quantum distribution scheme based on non-orthogonal state pairs has recently been published which considerably outperforms known schemes. This article describes the fundamentals of this protocol which are represented as an algorithm and the pseudo-code of the most relevant functions of the system is shown; The current development of the software for the distillation of non-orthogonal quantum states by means of binary frames is presented, which demonstrates the transmission control, reconciliation and privacy amplification of the shared secret bits. Likewise, we present the results obtained from the computer system and its interpretation in relation to the efficiency of the protocol, which exceeds 50% channel error rates and a quadratic growth of the length of the secret key as a function of the number of double detection events. Objectives: Demonstrate the effectiveness of the non-orthogonal state distillation protocol through binary frames using the software developed. Methodology: For the development of this project, the following methodology has been carried out (see Figure 1). Contribution: The results of this software guide tests for quantum distillation in an experimental communications environment in order to provide a useful solution in the era of quantum information transmission and communication technologies.
In this work, we introduce a new method for the establishment of a symmetric secret key through the reconciliation process in QKD systems that, we claim, is immune to the error rate of the quantum channel and, therefore, has an efficiency of 100% since it does not present losses during the distillation of secret keys. Furthermore, the secret rate is scaled to the square of the number of pulses on the destination side. The method only requires a single data exchange from Bob over the classic channel. We affirmed that our results constitute a milestone in the field of QKD and error correction methods at a crucial moment in the development of classical and quantum cryptanalytic algorithms. We believe that the properties of our method can be evaluated directly since it does not require the use of complex formal-theoretical techniques. For this purpose, we provide a detailed description of the reconciliation algorithm. The strength of the method against PNS and IR attacks is discussed. Furthermore, we define a method to analyze the security of the reconciliation approach based on frames that are binary arrays of 2×2. As a result, we came to the conclusion that the conjugate approach can no longer be considered secure, while we came up with a way to increase the secret gain of the method with measured bits.
Cryptography is being introduced to secure data. Through Classical Cryptographic technique, we can encrypt our data and secure secret key also. But classical cryptography is based on mathematical techniques where reversing one-way function is possible with sufficient computing power and time. So, Quantum Cryptography is introduced to overcome those drawbacks of traditional classical cryptography. It is based on the values of quantum mechanics and photon. Scientists and researchers have brought up a new key distribution protocol based on Quantum Cryptography is called Quantum Key Distribution (QKD) Protocol. The first QKD protocol BB84 was introduced by Charles Bennett and Gilles Brassard in 1984. After that several QKD protocols have been created. In this paper we have improved BB84 Protocol by removing the drawbacks of the existing algorithm towards Eavesdropping which may not be detected or disclosing large portion of secret key. Steps of the existing BB84 algorithm along with the modified one is described in detail with example and pseudo code. Limitations of BB84 and comparative study of both the existing and the improved one based on their security has been made and described in this current work.
Irrespective of the duration for which the classical system based on bits remains secure, the imminent advent of quantum systems demands a robust cryptographic mechanism to safeguard both manifest data and the existing system’s structure and infrastructure against various threats. Quantum mechanics may provide a solution in the form of quantum key distribution (QKD), a set of processes designed to generate and exchange cryptographic keys between two parties. Each unique method and algorithm within QKD can be characterized as a protocol. In 1984, Charles Bennett and Gilles Brassard introduced the first QKD protocol, BB84. Subsequent QKD protocols have been developed based on different principles, including Heisenberg’s uncertainty principle, polarization, entanglement, and the non-cloning theory. Other scientists have enhanced some QKD protocols, leading to variations with different names. However, not all these protocols can be implemented in classical systems, as they specifically require a quantum system. The current challenge revolves around the complex and pressing need to develop a QKD protocol that can function effectively on classical systems, quantum systems, or both. In the chapter, QKD protocols are comprehensively examined, with each protocol being meticulously reviewed through technical steps elucidating how the protocol facilitates the exchange of secret keys. Each QKD protocol is dissected to unveil its underlying mechanisms, providing a detailed exploration of the cryptographic procedures involved in generating and exchanging secure cryptographic keys.
The publication of the BB84 protocol by Bennett and Brassard in 1984 [10] marks the beginning of quantum key distribution. Since then, many other protocols have been invented. Yet, BB84 keeps a privileged place in the list of existing protocols: it is the one most analyzed and most often implemented, including those used in commercial products, e.g., [91, 113]. In this chapter, I define the BB84 protocol, although I already described it informally in Section 1.1. The physical implementation is then investigated. Finally, I analyze the eavesdropping strategies against BB84 and deduce the secret key rate. Description Alice chooses binary key elements randomly and independently, denoted by the random variable X ∈ χ = {0, 1}. In this protocol, there are two encoding rules, numbered by i ∈ {1, 2}. Alice randomly and independently chooses which encoding rule she uses for each key element. In case 1, Alice prepares a qubit from the basis {|0〉, |1〉} as In case 2, Alice prepares a qubit from the basis {|+〉, |−〉} as On his side, Bob measures either Z or X , yielding the result Y Z or Y X , choosing at random which observable he measures. After sending a predefined number of qubits, Alice reveals to Bob the encoding rule for each of them. They proceed with sifting, that is, they discard the key elements for which Alice used case 1 (or case 2) and Bob measured Z (or X ). For the remaining (sifted) key elements, we denote Bob's sifted measurements by Y .