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.
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.
Previously, using the conjugate frame-based reconciliation approach, we defined a method to correct errors produced in pairs of non-orthogonal quantum states that are transmitted through a quantum key distribution (QKD) link. The security of the frame-based reconciliation was discussed in order to deal with Photon Number Division (PNS) attack and Intercept and Forward (IR) attack, among others. However, until the time of publication we did not have the distillation software to test our method. In this article, following the conjugate frame distillation method, we present the implementation of the post-processing system that demonstrates that it is capable of correcting errors in the presence of error rates close to unity. The system shows that when the number of double-sensing events at Bob's station is as low as 100, the number of secret bits stays above 4500 bits in about 12 seconds, giving a secret rate of 375 bits per second while that the channel error rate reaches 90\%.
Quantum cryptography (or quantum key distribution) is a state-of-the-art technique that exploits properties of quantum mechanics to guarantee the secure exchange of secret keys. This 2006 text introduces the principles and techniques of quantum cryptography, setting it in the wider context of cryptography and security, with specific focus on secret-key distillation. The book starts with an overview chapter, progressing to classical cryptography, information theory (classical and quantum), and applications of quantum cryptography. The discussion moves to secret-key distillation, privacy amplification and reconciliation techniques, concluding with the security principles of quantum cryptography. The author explains the physical implementation and security of these systems, enabling engineers to gauge the suitability of quantum cryptography for securing transmission in their particular application. With its blend of fundamental theory, implementation techniques, and details of recent protocols, this book will be of interest to graduate students, researchers, and practitioners in electrical engineering, physics, and computer science.
Recent advances in quantum computing and quantum information theory represent a severe threat to the current state of the art of data protection. In this context, new quantum-safe techniques have emerged in recent decades, which fall into post-quantum and unconditionally secure cryptographic schemes. The firsts rely on computational problems supposed to be hard also for quantum computers. In contrast, the seconds do not depend on the difficulty of a computational problem and are therefore immune to quantum power. In particular, unconditionally secure techniques include Quantum Key Distribution (QKD) protocols for transmitting secret keys thanks to the quantum properties of light. In this work, we discuss QKD networks and post-quantum algorithms, considering their opportunities and limitations and showing that reconciliation between these two directions of cryptography is feasible and necessary for the quantum era.This work is part of the activities of the PON project “Development of quantum systems and technologies for IT security in communication networks” (QUANCOM) which aims to the realization of a metropolitan quantum communication network through the collaboration between universities, research centers and companies operating in the communication market area.
The secure distribution of the secret random bit sequences known as {open_quotes}key{close_quotes} material, is an essential precursor to their use for the encryption and decryption of confidential communications. Quantum cryptography is an emerging technology for secure key distribution with single-photon transmissions, nor evade detection (eavesdropping raises the key error rate above a threshold value). We have developed experimental quantum cryptography systems based on the transmission of non-orthogonal single-photon states to generate shared key material over multi-kilometer optical fiber paths and over line-of-sight links. In both cases, key material is built up using the transmission of a single-photon per bit of an initial secret random sequence. A quantum-mechanically random subset of this sequence is identified, becoming the key material after a data reconciliation stage with the sender. In our optical fiber experiment we have performed quantum key distribution over 24-km of underground optical fiber using single-photon interference states, demonstrating that secure, real-time key generation over {open_quotes}open{close_quotes} multi-km node-to-node optical fiber communications links is possible. We have also constructed a quantum key distribution system for free-space, line-of-sight transmission using single-photon polarization states, which is currently undergoing laboratory testing. 7 figs.
Quantum cryptography is a well-stated field within quantum applications where quantum information is used to set secure communications, authentication, and secret keys. Now used in quantum devices with those purposes, particularly Quantum Key Distribution (QKD), which proposes a secret key between two parties free of effective eavesdropping, at least at a higher level than classical cryptography. The best-known quantum protocol to securely share a secret key is the BB84 one. Other protocols have been proposed as adaptations of it. Most of them are based on the quantum indeterminacy for non-orthogonal quantum states. Their security is commonly based on the large length of the key. In the current work, a BB84-like procedure for QKD based on double quantum teleportation allows the sharing of the key statement using several parties. Thus, the quantum bits of information are assembled among three parties via entanglement, instead of travelling through a unique quantum channel as in the traditional protocol. Asymmetry in the double teleportation plus post-measurement retains the secrecy in the process. Despite requiring more complex control and resources, the procedure dramatically reduces the probability of success for an eavesdropper under individual attacks, because of the ignorance of the processing times in the procedure. Quantum Bit Error Rate remains in the acceptable threshold and it becomes configurable. The article depicts the double quantum teleportation procedure, the associated control to introduce the QKD scheme, the analysis of individual attacks performed by an eavesdropper, and a brief comparison with other protocols.
Quantum Key Distribution (QKD) which is the name of cryptography in quantum environment act as the highest developed area in quantum communication and computing technology (QCIT). \n \nQKD is inventive technology which utilize the laws of quantum to create a cryptographic share key to make the communication system secure. The unique feature of QKD assures eavesdropping detectable during quantum communications which is fascinating for a high-level secure environment.Most of the traditional cryptographic methods which we use currently are based on mathematical scheme or Computational complexity theory which are not completely safe. Using quantum cryptography has been achieved extensive steps in communication security establishment. As the information Unit has been changed from “bit” to Quantum bit (Qubit), a new element has been offered that can guarantee the shared information confidentiality between parties. The confidentiality of system is established via exchanging a secret key through a channel of quantum, the key which we use for encrypting the shared data. This structure has quantum integration which has been developed by physics law and techniques of cryptography. \n \nThis thesis has proposed a modified version of QKD protocol, this new protocol will generate a cryptographic share key for a more efficient, lower cost and secure communication between two parties (sender and Receiver). This new protocol principal is similar to BBM92, but the source of photon moved to sender instead of third-party photon generator, following steps will be executed in this Experiment: \n \n•\tObserve different categories protocols of QKD in details \n•\tThe Quantum Mechanics Visualisation Project (QuVis) is the simulation software that has been used for implementing the proposed protocol [BB84 with spin] among the other three (BBM92, B92 and BB84). \n•\tProbability ratio of error will be tested and compared for all protocols, for this experiment 100 to 5000 photons will be sent. \n \nBy Analysing collected data in this experiment, it will be determined which one of this four protocols lead the detecting of eavesdropping. Simulation software accomplishes the value of error key probability which receiver can use and should not pass over the range limit of 0.25 & 0.5.