Quantum random number generators (QRNGs) have important applications in cryptographic protocols, games, and lotteries, among others. In contrast with software-based pseudorandom number generators, the number sequence generated is truly random. Most QRNGs found in the literature are based on single-photon sources and detectors. In this letter, we discuss the advantages and disadvantages of a QRNG that uses only one single-photon detector and weak coherent or thermal states as light source.
Quantum random number generators (QRNGs) have important applications in cryptographic protocols, games, and lotteries, among others. In contrast with software-based pseudorandom number generators, the number sequence generated is truly random. Most QRNGs found in the literature are based on single-photon sources and detectors. In this letter, we discuss the advantages and disadvantages of a QRNG that uses only one single-photon detector and weak coherent or thermal states as light source.
Quantum random number generators (QRNG) have important applications in cryptographic protocols, gaming and lotteries, among others. In contrast to pseudo-random number generators based on software, the sequence of random numbers generated is truly random. Most QRNG found in the literature are based on optoelectronic devices like single-photon sources and single-photon detectors. In this direction, the present dissertation deals with the theory and experiment QRNG based photonic systems, taking into account QRNG using discrete and continuous variables. In particular, three issues were considered: 1) a new model of continuous variable QRNG based on light polarization was proposed. 2) The performance of a QRNG employing only one single-photon detector, taking into account the afterpulsing and the quantum light state used, coherent or thermal, was realized. 3) A QRNG with binomial distribution was built.
Random numbers are a fundamental resource in science and engineering, and are also widely used in many fields, such as simulation, cryptography, lotteries, fundamental science. There are algorithmically generated numbers that look like random numbers but are not truly random. These pseudo random numbers are generated from a computer, using deterministic algorithms. Because, we cannot use pseudo random generators in situations, where true randomness is necessary, we use true random number generators. In this case, we use unpredictable random events as a random source. Quantum random number generators (QRNG) output true random numbers based on inherent randomness in quantum measurements. Our goal is to generate fast random numbers at a lower cost. At the same time, a high level of randomness is essential. We present the improved novel quantum random number generator, which is based the on time of arrival QRNG. It is rather efficient, as it uses the simple version of the detectors with rather few requirements. The novel QRNG produces more than one random bit per each photon detection.
Quantum random number generators (QRNG) have important applications in cryptographic protocols, gaming and lotteries, among others. In contrast to pseudo-random number generators based on software, the sequence of random numbers generated is truly random. Most QRNG found in the literature are based on optoelectronic devices like single-photon sources and single-photon detectors. In this direction, the present dissertation deals with the theory and experiment QRNG based photonic systems, taking into account QRNG using discrete and continuous variables. In particular, three issues were considered: 1) a new model of continuous variable QRNG based on light polarization was proposed. 2) The performance of a QRNG employing only one single-photon detector, taking into account the afterpulsing and the quantum light state used, coherent or thermal, was realized. 3) A QRNG with binomial distribution was built.
Random number generators (RNG) are an important resource in many areas: cryptography (both quantum and classical), probabilistic computation (Monte Carlo methods), numerical simulations, industrial testing and labeling, hazard games, scientific research etc. Because today's computers are deterministic, they can not create random numbers unless complemented with a physical RNG. Randomness of a RNG can be defined and scientifically characterized and measured. Especially valuable is the information-theoretic provable RNG which, at state of the art, seem to be possible only by harvest of randomness inherent to certain (simple) quantum systems and such a generator we call Quantum RNG (QRNG). On the other hand, current industry standards dictate use of RNGs based on free running oscillators (FRO) whose randomness is derived from electronics noise present in logic circuits and which, although quantum in nature, cannot be strictly proven. This approach is currently used in FPGA and ASIC chips. We compare weak and strong aspects of the two approaches for use in cryptography and in general. We also give an alternative definition of randomness, discuss usage of single photon detectors in realization of QRNGs and give several examples where QRNG can significantly improve security of a cryptographic system.
Quantum random number generators (QRNGs) are an integral part of quantum key distribution (QKD) systems. To better understand the inherent physical processes, we compare the random numbers generated by two separate schemes, one is based on entropy (arrival time of photons) and another with an additional source of entropy (space) i.e, path superposition of arrival time of photons from a weak coherent source on a gated InGaAs single photon detector. Both experiments yield bits that appear random. However, they satisfy different criteria of randomness. The weak coherent source has a Poissonian distribution and extracting the variation about the arrival time of photons on gated SPD yields a source of random numbers that pass most of the Dieharder Tests. With the inclusion of superposition, we obtain random numbers that pass all the Dieharder tests. The physical origins of the random numbers in the two experiments is different, one is single entropy source based and other one is two entropy source based, and this is reflected in the outcomes of the different tests for randomness.
The prototype quantum random number (random bit) generators (QRNG) consists of one photon at a time falling on a 50:50 beam splitter followed by random detection in one or the other other output beams due to the irreducible probabilistic nature of quantum mechanics. Due to the difficulties in producing single photons on demand, in practice, pulses of weak coherent (laser) light are used. In this paper we take a different approach, one that uses moderate coherent light. It is shown that a QRNG can be implemented by performing photon-number parity measurements. For moderate coherent light, the probabilities for obtaining even or odd parity in photon counts are 0.5 each. Photon counting with single-photon resolution can be performed through use of a cascade of beam splitters and single-photon detectors as was done recently in a photon-number parity-based interferometry experiment involving coherent light.