In this work, we present a study of a quantum random number generation system based on a branching path approach with spatial superposition principle, realised using fibre optics. The analysis of the experimental system was supported by the development of a stochastic model of the entropy source, which, to the best of the authors' knowledge, has not yet been properly described. This resulted in the analytical equations for the probability of possible output quantum states depending on the initial properties of the system. Based on the presented model, the quantum efficiency and the Shannon entropy were calculated and compared with experimentally obtained values, which resulted in full agreement between these data. Additional statistical tests were performed on random numbers obtained theoretically and experimentally to confirm their high degree of randomness and their usability in cryptographic applications. The fact that the developed system is based on fibre optics allows it to operate in stable conditions with a final efficiency at the level of 15%, which provides a random number generation rate of about 8 kb/s. The developed system is used as an input to the quantum key distribution system, which has possible applications in cryptography or military and commercial secure communications.
In this work, we present a study of a quantum random number generation system based on a branching path approach with spatial superposition principle, realised using fibre optics. The analysis of the experimental system was supported by the development of a stochastic model of the entropy source, which, to the best of the authors' knowledge, has not yet been properly described. This resulted in the analytical equations for the probability of possible output quantum states depending on the initial properties of the system. Based on the presented model, the quantum efficiency and the Shannon entropy were calculated and compared with experimentally obtained values, which resulted in full agreement between these data. Additional statistical tests were performed on random numbers obtained theoretically and experimentally to confirm their high degree of randomness and their usability in cryptographic applications. The fact that the developed system is based on fibre optics allows it to operate in stable conditions with a final efficiency at the level of 15%, which provides a random number generation rate of about 8 kb/s. The developed system is used as an input to the quantum key distribution system, which has possible applications in cryptography or military and commercial secure communications.
The generation of series of random numbers is an important and difficult problem. Appropriate measurements on entangled states have been proposed as the definitive solution to produce series of certified randomness, and quantum optical systems play a major role. However, several reports indicate that random number generators based on quantum measurements have a high rate of series rejected by standard tests of randomness. This is believed to be caused by experimental imperfections and is usually solved by using classical algorithms to extract randomness. This is acceptable to generate random numbers in a single place. In quantum key distribution (QKD) instead, if the extractor is known by an eavesdropper (a situation that cannot be ruled out), the key's security may be menaced. We use a not-loophole-free, "toy" all-fiber-optic-based setup, mimicking a QKD one operating in the field, to generate binary series and evaluate their level of randomness according to Ville's principle. The series are tested with a battery of indicators of statistical and algorithmic randomness and nonlinear analysis. The good performance of a simple method to get random series from rejected ones, previously reported by Solis et al. is confirmed and supported with additional arguments. Incidentally, a theoretically predicted relationship between complexity and entropy is verified. Regarding QKD, the level of randomness of series, obtained by applying Toeplitz's extractor to rejected series, is found to be indistinguishable from the level of non-rejected raw ones.
Random Number Generators (RNGs) are crucial for applications ranging from cryptography to simulations. Depending on the source of randomness, RNGs are classified into Pseudo-Random Number Generators (PRNGs), True Random Number Generators (TRNGs), and Quantum Random Number Generators (QRNGs). This work presents the end-to-end development of a high-speed, high-efficiency, phase-noise-based QRNG system that taps into the quantum phase noise of a single-frequency laser, with randomness originating from spontaneous emission. Using a self-heterodyne measurement with a semiconductor laser (linewidth ≈ 5.23 GHz) operated near threshold and a $\sim$48 cm fiber delay line, a raw data generation rate of 2.0 Gbps is achieved. To ensure uniform randomness in the QRNG output, robust extraction techniques developed in-house, such as the Toeplitz Strong Extractor (TSE), are used. Randomness validation using the NIST and Diehard test suites confirms that all statistical tests pass at standard confidence levels. The developed system achieves a post-processed generation rate of 1.0 Gbps in operation and attains a Technology Readiness Level (TRL) of 7, approaching TRL 8, making it suitable for real-time secure applications such as cryptographic key generation and stochastic modeling.
Quantum random number generators (QRNG) are the prime source of randomness, by exploiting the unpredictable nature of Quantum mechanics QRNG aims to provide a string of completely random utterly unpredictable numbers. QRNGs are crucial for cryptography, scientific calculation, simulation, and many more real-world applications. Our Optical Quantum Random Number Generator (OQRNG) utilizes a high-speed pulsating laser, a Polarizing beam splitter (PBS), photodetectors, and advanced signal processing units that capture and digitize random photon intensity forming the raw random bit stream. This technique is famously known as Branching Path Technique. After that, we implement rigorous testing that encompasses the statistical randomness tests developed by National Institute of Standards and Technology (NIST) to ensure the guaranteed ran-domness meets security standards. A user-friendly Graphic user interface (GUI) simplifies interaction with the QRNG allowing the user to configure device settings, monitor system performance, and securely extract random numbers. Our findings help us demonstrate the superiority of QRNGs over classical random number generators, and highlight the potential of photon-based QRNGs and their environmentally friendly and efficient random number generation.
Generating high-speed, verifiable random numbers is a fundamental requirement for cryptography, large-scale stochastic simulations, and secure quantum communication. Here, we present a robust quantum random number generator that utilizes the spatial distribution of quantum fluctuations captured by an electron-multiplying charge-coupled device operated in high-speed kinetic mode. Through rigorous detector calibration and shot-noise analysis, we characterize the spatial quantum noise obtained from the spatial intensity fluctuations of the coherent states of light. Such quantum noise serves as a high-entropy source, enabling an instantaneous random bit generation rate of 5.92 Gbps without algorithmic randomness extraction in the present configuration. The sustained output rate is, however, limited to 7.5 Mbps by the bandwidth of the serial electronic readout. The generated sequences successfully pass the NIST SP 800-22 and Marsaglia Diehard statistical test suites, confirming the high quality and unpredictability of the entropy source.
ABSTRACT Quantum random number generator (QRNG) platforms use principles of quantum mechanics to create truly random numbers. Traditional pseudo-random number generators (PRNGs) generate numbers based on deterministic formulas. QRNG's use of the principles of superposition and measurement can provide numbers that cannot be predicted or replicated; therefore, they have been used as a source of randomness in various fields. In this research project, an experimental QRNG was designed and built using Qiskit simulations. Each experiment consisted of a series of two-qubit circuits. The circuits were created to place both qubits into an equal probability state. This was done by applying a pair of Hadamard gates (Hadamard gate applies a rotation operator of π/2 radians). Then each circuit was measured. For each measurement, there would be one output from each qubit. Since the Hadamard gate creates an equal-probability superposition, the combination of each qubit will either add up to 1 or subtract from -1. These combinations will be recorded and processed through several methods to evaluate their quality. Those methods include: Shannon Entropy Analysis, Frequency Distribution Analysis and Chi-Square Uniformity Testing. Keywords: Quantum Random Number Generator, Quantum Computing, Quantum Measurement, Cryptography, Secure Randomness, Qiskit Simulation
Topicality. Reliable random number generation is one of the key requirements for modern cryptographic systems and cybersecurity applications. Traditional pseudo-random number generators are based on deterministic algorithms and may exhibit limited entropy and predictability, which can negatively affect information security. The subject of study in the article is methods of quantum random number generation and approaches to evaluating the quality of generated random sequences. The purpose of the article is to analyze modern methods of quantum random number generation, develop a software tool for obtaining quantum random numbers based on the ANU Quantum Random Number Generator service, perform statistical testing of the generated sequences, and analyze the obtained results. The following results were obtained. Modern quantum random number generation systems were analyzed and compared. A software tool was implemented in Python for automatic retrieval of quantum random numbers through the ANU QRNG API. The generated binary sequences were evaluated using Frequency Test and Block Frequency Test from the NIST SP 800-22 statistical test suite. The obtained p-values were 0.977181 and 0.200659 respectively, confirming successful completion of both tests. Additionally, visual analysis of the generated sequences revealed no noticeable patterns or repetitive structures. Conclusion. The obtained results confirm the high quality of quantum random sequences generated using ANU QRNG and demonstrate the applicability of the developed software tool for cryptographic and cybersecurity applications requiring high-quality randomness.