907 research outputs found
Enhancing quantum entropy in vacuum-based quantum random number generator
Information-theoretically provable unique true random numbers, which cannot
be correlated or controlled by an attacker, can be generated based on quantum
measurement of vacuum state and universal-hashing randomness extraction.
Quantum entropy in the measurements decides the quality and security of the
random number generator. At the same time, it directly determine the extraction
ratio of true randomness from the raw data, in other words, it affects quantum
random numbers generating rate obviously. In this work, considering the effects
of classical noise, the best way to enhance quantum entropy in the vacuum-based
quantum random number generator is explored in the optimum dynamical
analog-digital converter (ADC) range scenario. The influence of classical noise
excursion, which may be intrinsic to a system or deliberately induced by an
eavesdropper, on the quantum entropy is derived. We propose enhancing local
oscillator intensity rather than electrical gain for noise-independent
amplification of quadrature fluctuation of vacuum state. Abundant quantum
entropy is extractable from the raw data even when classical noise excursion is
large. Experimentally, an extraction ratio of true randomness of 85.3% is
achieved by finite enhancement of the local oscillator power when classical
noise excursions of the raw data is obvious.Comment: 12 pages,8 figure
Experimental study of quantum random number generator based on two independent lasers
Quantum random number generator (QRNG) can produce true randomness by
utilizing the inherent probabilistic nature of quantum mechanics. Recently, the
spontaneous-emission quantum phase noise of the laser has been widely deployed
for QRNG, due to its high rate, low cost and the feasibility of chip-scale
integration. Here, we perform a comprehensive experimental study of phase-noise
based QRNG with two independent lasers, each of which operates in either
continuous-wave (CW) or pulsed mode. We implement QRNGs by operating the two
lasers in three configurations, namely CW+CW, CW+pulsed and pulsed+pulsed, and
demonstrate their tradeoffs, strengths and weaknesses.Comment: 7pages,6figures.It has been accepted by PR
Geração de números verdadeiramente aleatórios baseados em ruído quântico
Quantum Random Number Generators (QRNGs) promise information-theoretic security
by exploring the intrinsic probabilistic properties of quantum mechanics. In
practice, their security frequently relies on a number of assumptions over physical
devices. In this thesis, a randomness generation framework that explores the
amplitude quadrature fluctuations of a vacuum state was analyzed. It employs a
homodyne measurement scheme, which can be implemented with low-cost components,
and shows potential for high performance with remarkable stability.
A mathematical description of all necessary stages was provided as security proof,
considering the quantization noise introduced by the analog-to-digital converter.
The impact of experimental limitations, such as the digitizer resolution or the
presence of excess noise due to an unbalanced detection, was characterized. Moreover,
we propose a framework to estimate the excess entropy introduced by an
unbalanced detection, and its high impact within the Shannon entropy model was
experimentally verified.
Furthermore, a real-time dedicated QRNG scheme was implemented and validated.
The variance characterization curve of the homodyne detector was measured, and
the quantum fluctuations were determined to be preponderant for an impinging
power PLO < 45.7mW. By estimating the worst-case min-entropy conditioned on
the electronic noise, approximately 8.39 true random bits can be extracted from
each sample, yielding a maximum generation rate of 8.23 Gbps. With a lengthcompatible
Toeplitz-hashing algorithm, these can be extracted at 75 Mbps with an
upper security bound of 2−105, which illustrates the quality of this implementation.
Moreover, the generation scheme was validated and verified to pass all the statistical
tests of the NIST, DieHarder, and TestU01’s SmallCrush batteries, as well as
most of TestU01’s Crush evaluations.
Finally, we propose a framework for time-interleaving the entropy source within
a classical communication channel, which removes the need for a dedicated generation
device. After assessing the conditions where quantum noise is dominant,
support for generation rates up to 1.3 Gbps was observed. The random bitstream
was subjected to the NIST randomness test suite and consistently passed all evaluations.
Moreover, a clean quadrature phase shift keying constellation was recovered,
which supports the multi-purpose function of the scheme.Geradores quânticos de números aleatórios (QRNGs) prometem sistemas
informação-teoricamente seguros explorando as propriedades intrinsecamente probabilísticas
da mecânica quântica. No entanto, experimentalmente, um conjunto
de pressupostos é tipicamente imposto sobre os dispositivos experimentais. Nesta
dissertação, analisou-se uma abordagem para geração de números aleatórios que
explora as flutuações de amplitude em quadratura de um estado vácuo. Para tal,
recorre-se a um esquema de deteção homodina que permite um elevado desempenho
e estabilidade, requerendo apenas dispositivos de baixo custo.
Um modelo matemático das diferentes etapas do gerador foi desenvolvido de forma
a fornecer uma prova de segurança, e contabilizou-se o ruído de discretização introduzido
pelo conversor analógico-digital. Adicionalmente, caracterizou-se o impacto
de imperfeições experimentais como a resolução do conversor analógico-digital e a
presença de ruído em excesso como consequência de uma deteção não balanceada.
Uma abordagem para estimar esta contribuição no modelo de entropia de Shannon
foi também proposta e experimentalmente verificada.
Adicionalmente, uma implementação em tempo-real foi caracterizada. A curva
de caracterização do detetor homodino foi experimentalmente verificada, e uma
preponderância de ruído quântico observado para potências óticas inferiores a
45.7mW. Através de uma estimativa da min-entropy condicionada ao ruído eletrónico,
aproximadamente 8.39 bits por medição podem ser extraídos, o que corresponde
a uma taxa de geração máxima de 8.23 Gbps. Estes podem ser extraídos
a uma taxa de 75 Mbps com um parâmetro de segurança de 2−105, ilustrativo da
qualidade desta implementação, através de um algoritmo eficiente de multiplicação
de matrizes de Toeplitz. Posteriormente, o esquema foi validado, passando todos
os testes estatísticos das baterias NIST, DieHarder, e SmallCrush, assim como a
maioria das avaliações contidas na bateria Crush.
Por último, foi proposta uma abordagem para integrar esta fonte de entropia num
canal de comunicação clássico, removendo desta forma a necessidade de uma implementação
dedicada. Após avaliação das condições de preponderância do ruído
quântico, foram observadas taxas de geração até 1.3 Gbps. Os números obtidos
foram também submetidos à bateria de testes do NIST, passando consistentemente
todas as avaliações. Adicionalmente, a constelação de modulação de amplitude em
quadratura obtida viabiliza a operação multifuncional do sistema.Mestrado em Engenharia Físic
A Novel TRNG Based on Traditional ADC Nonlinear Effect and Chaotic Map for IoT Security and Anticollision
In the rapidly developing Internet of Things (IoT) applications, how to achieve rapid identification of massive devices and secure the communication of wireless data based on low cost and low power consumption is the key problem to be solved urgently. This paper proposes a novel true random number generator (TRNG) based on ADC nonlinear effect and chaotic map, which can be implemented by traditional processors with built-in ADCs, such as MCU, DSP, ARM, and FPGA. The processor controls the ADC to sample the changing input signal to obtain the digital signal DADC and then extracts some bits of DADC to generate the true random number (TRN). At the same time, after a delay based on DADC, the next time ADC sampling is carried out, and the cycle continues until the processor stops generating the TRN. Due to the nonlinear effect of ADC, the DADC obtained from each sampling is stochastic, and the changing input signal will sharply change the delay time, thus changing the sampling interval (called random interval sampling). As the input signal changes, DADC with strong randomness is obtained. The whole operation of the TRNG resembles a chaotic map, and this method also eliminates the pseudorandom property of chaotic map by combining the variable input signal (including noise) with the nonlinear effect of ADC. The simulation and actual test data are verified by NIST, and the verification results show that the random numbers generated by the proposed method have strong randomness and can be used to implement TRNG. The proposed TRNG has the advantages of low cost, low power consumption, and strong compatibility, and the rate of generating true random number is more than 1.6 Mbps (determined by ADC sampling rate and processor frequency), which is very suitable for IoT sensor devices for security encryption algorithms and anticollision
Coherence-based quantum random number generator
Theoretical design and experimental demonstration of a random number generator based on the random interference of optical signalsWe consider the random change of the phase of a laser as the physical source of randomness that allows the implementation a new type of quantum random number generator (QRNG) . We analyze the phase noise model of a laser and study how randomness can be extracted with the help of optical coherent detection. We also demonstrate an ultra-fast QRNG of up to 19 Gbits/s of random numbers that use commercial devices already found in the laboratory
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