Article
Engineering, Electrical & Electronic
Ken Tanizawa, Kentaro Kato, Fumio Futami
Summary: This study reports a quantum entropy source that utilizes a single laser diode and parallel homodyne measurement to achieve fast random number generation. By using a distributed feedback laser diode and a planar lightwave circuit splitter, this technology enables high-speed and multi-channel random number generation.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Physics, Applied
Bing Bai, Jianyao Huang, Guan-Ru Qiao, You-Qi Nie, Weijie Tang, Tao Chu, Jun Zhang, Jian-Wei Pan
Summary: Quantum random number generators can produce true random numbers, but speed and size are the two most important compromised parameters for practical applications. This study presents the fastest and miniaturized QRNG with a record real-time output rate of 18.8 Gbps by combining a photonic integrated chip and optimized randomness extraction technology, demonstrating excellent characteristics of integration and high-frequency response.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Applied
Hong Jie Ng, Shuhan Yang, Zhaoyang Yao, Hyunsoo Yang, Charles Lim
Summary: In recent years, there has been increasing interest in true random number generators (TRNGs) based on magnetic tunnel junctions (MTJs). These MTJ-based TRNGs offer advantages such as smaller size and simpler structure compared to traditional CMOS-based TRNGs. However, unlike CMOS-based TRNGs, the quality of raw output from MTJ-based TRNGs has not been quantified and randomness extraction has not been performed to produce provably secure random bits. In this work, we implement a MTJ-based TRNG and measure the entropy of its raw output. Based on this information, we perform postprocessing to extract a set of provably secure random bits.
PHYSICAL REVIEW APPLIED
(2023)
Article
Computer Science, Information Systems
Chao-Hsien Hsieh, Xinyu Yao, Qing Zhang, Mengchen Lv, Ruobing Wang, Bingxue Ni
Summary: Random numbers are widely used in various fields, and the current mechanism of generating random numbers by computers is at risk of being attacked. This paper proposes a secure random number generator (BCsRNG) based on blockchain technology, which improves the security of random numbers and provides an encapsulated function algorithm through smart contracts. Experimental results show that BCsRNG generates random numbers that are difficult to decrypt and have higher randomness and security.
Article
Multidisciplinary Sciences
Yanbao Zhang, Hsin-Pin Lo, Alan Mink, Takuya Ikuta, Toshimori Honjo, Hiroki Takesue, William J. Munro
Summary: Quantum random numbers are distinguishable due to their intrinsic unpredictability and are useful in various applications, with efforts put into their realization. This study demonstrates low-latency real-time certifiable randomness generation from measurements on photonic time-bin states, generating 8192 random bits every 0.12s. The quantum random number generator is suitable for a continuously-operating, high-security, and high-speed quantum randomness beacon.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Dinka Milovancev, Florian Honz, Nemanja Vokic, Martin Achleitner, Fabian Laudenbach, Christoph Pacher, Hannes Hubel, Bernhard Schrenk
Summary: This paper presents a design of balanced homodyne receivers suitable for ultra-low noise quantum applications. The design achieves high bandwidths while maintaining optimum noise performance. The experimental results demonstrate high quantum-to-classical noise ratios and common-mode rejection ratios, making it suitable for continuous-variable quantum key distribution and quantum random number generation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Multidisciplinary Sciences
Conor Ryan, Meghana Kshirsagar, Gauri Vaidya, Andrew Cunningham, R. Sivaraman
Summary: This work investigates the potential of using Grammatical Evolution (GE) to generate initial seeds for pseudo-random number generators (PRNGs) and cryptographically secure (CS) PRNGs. The study demonstrates the suitability of GE as an entropy source and shows that the initial seeds possess average entropy values close to the ideal value. Two random number generators, GE-PRNG and GE-CSPRNG, are constructed and their efficacy and performance are evaluated. The experimental results indicate their effectiveness and potential for industrial applications.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
Michal Melosik, Mariusz Galan, Mariusz Naumowicz, Piotr Tylczynski, Scott Koziol
Summary: This paper presents a prototype wearable Cryptographically Secure PseudoRandom Bit Generator (CSPRBG). The prototype vest includes a ZYBO Zynq Z-7010 evaluation board and implements a seed generator and block cryptographic algorithms for the generation of pseudo-random values. Sound and acceleration recordings from a microphone and accelerometer were used as entropy sources. Hardware implementations of selected block cryptographic algorithms, such as AES, Twofish, and 3DES, were made. The randomness of the binary values generated by the wearable CSPRBG was evaluated using statistical tests and ENT tests conducted by the National Institute of Standards and Technology (NIST), depending on the configuration of the entropy sources. The possibility of developing the wearable CSPRBG as a System on Chip (SoC) solution is also presented.
Article
Optics
Yao Zhou, Zhen-Qiu Zhong, Zhen-Qiang Yin, Rong Wang, Xiao-Hai Zhan, Shuang Wang, Wei Chen, Wei Huang, Bing-Jie Xu, Guang-Can Guo, Zheng-Fu Han
Summary: This article introduces a quantum random number generator (QRNG) protocol based on dimension witnesses, which can improve the generation rate of random numbers under different optical path losses and environmental disturbances. The authors also demonstrate a practical implementation of the protocol and compare it with previous methods. The method can also be applied to higher-dimensional quantum systems.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2022)
Article
Physics, Multidisciplinary
Youngrak Choi, Yongjin Yeom, Ju-Sung Kang
Summary: The efficient generation of high-quality random numbers is crucial for the operation of cryptographic modules. The quality of a random number generator is evaluated based on the min-entropy of its entropy source. Hash function-based entropy accumulation, while effective, tends to be slow. Therefore, a new efficient method is needed to accumulate entropy and improve the min-entropy of the output sequence.
Article
Quantum Science & Technology
Piotr Mironowicz, Gustavo Canas, Jaime Carine, Esteban S. Gomez, Johanna F. Barra, Adan Cabello, Guilherme B. Xavier, Gustavo Lima, Marcin Pawlowski
Summary: A method is proposed to protect semi-device-independent private quantum randomness generators against detection inefficiency attacks by introducing a blocking device that adds failures in communication between preparation and measurement devices. Protection against these attacks is demonstrated experimentally using weak coherent states and standard avalanche photo-detectors.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Multidisciplinary Sciences
Aina'u Shehu Muhammad, Fatih Ozkaynak
Summary: One of the general problems in modern digital society is the information security topic. A new image encryption algorithm, designed within the framework of the provable security design principle, has been proposed in this study. The hybrid random number generator used as the key generator meets statistical randomness properties and can be widely used in information security applications.
Article
Computer Science, Hardware & Architecture
A. Saini, A. Tsokanos, R. Kirner
Summary: This paper proposes a new framework called CryptoQNRG that evaluates the strength of random number generators (RNG)-based key-scheduling algorithms (KSAs) using a set of tests. The framework explores cryptographic properties such as unpredictability, balance of bits, correlation, confusion, and diffusion in the subkeys generated by RNG-based KSAs. An important outcome of this framework is the ability to distinguish between strong and weak RNG-based KSAs.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Physics, Applied
Alvaro Navarrete, Margarida Pereira, Marcos Curty, Kiyoshi Tamaki
Summary: The study introduces a new quantum key distribution protocol to bridge the gap between theory and practice. This protocol, based on the transmission of coherent light, proves its security against various imperfections and side channels, accommodating information leakage and providing a secret key rate significantly higher than traditional DI QKD.
PHYSICAL REVIEW APPLIED
(2021)
Article
Mathematics, Interdisciplinary Applications
Christiana Chamon, Shahriar Ferdous, Laszlo B. Kish
Summary: This paper demonstrates the vulnerability of the Kirchhoff-Law-Johnson-Noise (KLJN) secure key exchanger to compromised random number generator(s) and explores how Eve can crack the secure key using Ohm's Law in two different situations.
FLUCTUATION AND NOISE LETTERS
(2021)
Article
Physics, Multidisciplinary
Jens A. H. Nielsen, Jonas S. Neergaard-Nielsen, Tobias Gehring, Ulrik L. Andersen
Summary: The modern scientific method relies on precise measurements of physical parameters. The measurement of optical phase, for example, is conventionally limited by the Heisenberg limit. However, deterministic phase estimation with N00N states has not yet reached or surpassed this limit. In this study, we use a scheme based on Gaussian squeezed vacuum states and high-efficiency homodyne detection to achieve phase estimates with extreme sensitivity that surpasses the shot noise limit and even the conventional Heisenberg limit.
PHYSICAL REVIEW LETTERS
(2023)
Article
Quantum Science & Technology
Cedric Bruynsteen, Tobias Gehring, Cosmo Lupo, Johan Bauwelinck, Xin Yin
Summary: Emerging communication and cryptography applications require reliable fast unpredictable random number generators. Quantum random number generation utilizes the inherent randomness in quantum mechanics to create truly unpredictable numbers. Although using the quantum vacuum state to generate random numbers is a popular approach, its speed has often been limited compared to other schemes. In this study, we demonstrate experimentally an ultrafast generation rate of 100 Gbit/s for vacuum-based quantum random number generation, setting a new record by one order of magnitude. The secure random number generator in the chip-scale platform holds promise for next-generation communication and cryptography applications.
Article
Quantum Science & Technology
Jasminder S. Sidhu, Michael S. Bullock, Saikat Guha, Cosmo Lupo
Summary: Coherent states of the quantum electromagnetic field are ideal for optical communications, but little is known about the practical realization of receivers for unambiguous state discrimination. This study fills this gap by outlining a theory of unambiguous state discrimination using passive multimode linear optics, phase-space displacements, auxiliary vacuum modes, and on-off photon detection. The results show that these currently available optical components can achieve near-optimal unambiguous discrimination of multiple, multimode coherent states in certain regimes.
Article
Optics
Anders J. E. Bjerrum, Jonatan B. Brask, Jonas S. Neergaard-Nielsen, Ulrik L. Andersen
Summary: In this paper, an all-optical setup is analyzed, which achieves Bell-inequality violation over long distances by using probabilistic entanglement swapping. The setup consists of two-mode squeezers, displacements, beamsplitters, and on-off detectors. The arrangement of events to close both the detection and locality loopholes is described. A scenario with dichotomic inputs and outputs is analyzed, and the robustness of Bell inequality violation is checked for up to six parties, considering phase, amplitude, dark count noise, and loss.
Article
Optics
Paul M. Alsing, Carlo Cafaro, Orlando Luongo, Cosmo Lupo, Stefano Mancini, Hernando Quevedo
Summary: In this paper, the authors discuss the relation between the Sjoqvist metric and the Bures metric for mixed quantum states using decompositions of density operators by means of ensembles of pure quantum states. They compare the formal expressions of these metrics for thermal quantum states and illustrate the difference between them in a simple physical system. Finally, the Bures and Sjoqvist metrics are compared in terms of their monotonicity property.
Article
Optics
Anders J. E. Bjerrum, Jonatan B. Brask, Jonas S. Neergaard-Nielsen, Ulrik L. Andersen
Summary: This study investigates the storage and purification of a photon-loss-affected two-mode squeezed vacuum state using noiseless amplification with solid-state qubits. The proposed method increases entanglement between the parties sharing the state probabilistically. The amplification step involves transferring the state from an optical mode to a set of solid-state qubits acting as a quantum memory, similar to a set of quantum scissors.
Article
Optics
Frederik Werner Isaksen, Ulrik Lund Andersen
Summary: A mechanical system can be optimally controlled through continuous measurements of its position followed by feedback. Using the complete formalism, without invoking the standard rotating-wave approximation and the adiabatic approximation, we deduce the conditional and unconditional states of a mechanical oscillator that lead to mechanical cooling and mechanical squeezing. The exact solutions significantly differ from the approximate solutions, highlighting the importance of using the complete model. Additionally, we demonstrate that the conditional and unconditional states cannot coincide in a typical control scheme, even with infinite feedback strength.
Article
Optics
Zixin Huang, Christian Schwab, Cosmo Lupo
Summary: One of the challenges in exoplanet science is to determine the composition of their atmosphere and find signs of biochemical processes. This study establishes the quantum limit for detecting spectral absorption lines from dim exoplanets in the presence of bright stellar sources. By using structured measurements based on spatial demultiplexing, the researchers were able to separate the light from the planet and achieve the ultimate quantum limits.
Proceedings Paper
Optics
Nitin Jain, Ivan Derkach, Hou-Man Chin, Radim Filip, Ulrik L. Andersen, Vladyslav C. Usenko, Tobias Gehring
Summary: This article examines the flaws in the practical implementation of key bit encoding in continuous-variable quantum key distribution systems and the presence of side channels. Various strategies for exploiting the vulnerability are investigated, and the impact of modulation leakage on the security of the key distribution protocol is theoretically assessed.
EMERGING IMAGING AND SENSING TECHNOLOGIES FOR SECURITY AND DEFENCE VII
(2022)
Review
Optics
Marie Ioannou, Bradley Longstaff, Mikkel Larsen, Jonas S. Neergaard-Nielsen, Ulrik L. Andersen, Daniel Cavalcanti, Nicolas Brunner, Jonatan Bohr Brask
Summary: High-quality randomness is crucial for secure information processing. This study presents a scheme for quantum randomness certification based on quantum steering. The scheme is one-sided device independent and can achieve high security with simple states and measurements. It is also immune to the detection loophole, making it the closest to full device independence using purely Gaussian states and measurements.
Proceedings Paper
Engineering, Electrical & Electronic
Nitin Jain, Hou-Man Chin, Hossein Mani, Erik Bidstrup, Ulrik L. Andersen, Tobias Gehring
Summary: Continuous-variable quantum cryptography utilizes existing telecommunication technology for secure key distribution, and qTReX is a low-noise, highly stable, semi-autonomous prototype using optical coherent states.
2022 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)
(2022)
Article
Materials Science, Multidisciplinary
Andreas F. L. Poulsen, Joshua D. Clement, James L. Webb, Rasmus H. Jensen, Luca Troise, Kirstine Berg-Sorensen, Alexander Huck, Ulrik Lund Andersen
Summary: In this study, we demonstrate the efficient and coherent control of a large defect ensemble for sensing using Floquet theory and optimal control optimization methods. By optimizing the microwave control pulses, we achieve an improvement in the strength of ensemble response, and identify the bandwidth limitations of large-ensemble reinitialization and propose alternative routes for further improvement.
Article
Quantum Science & Technology
Cillian Harney, Stefano Pirandola
Summary: In this work, a large-scale quantum network model called weakly regular architectures is introduced to study the design of global quantum networks. Through a comparison of theoretical performance and realistic satellite quantum communication protocols, the efficacy of satellite-based technologies for global quantum communications is rigorously proven.
Article
Physics, Multidisciplinary
Alexander G. Mountogiannakis, Panagiotis Papanastasiou, Boris Braverman, Stefano Pirandola
Summary: Continuous-variable quantum key distribution establishes a secret key between two remote parties using Gaussian-modulated coherent states. The secret key rate depends on the loss and noise in the communication channel, as well as the data processing steps of parameter estimation, error correction, and privacy amplification. High signal-to-noise regime requires high-rate low-density parity check codes.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Athena Karsa, Jacques Carolan, Stefano Pirandola
Summary: Channel-position finding is the task of determining the location of a target channel, and using quantum states and entanglement can provide quantum advantages. By considering different quantum sources, quantum enhancement can be achieved.
