Quantum key distribution is the process of using quantum communication to establish a shared key between two parties. It has been demonstrated the unconditional security and effective communication of quantum communication system can be guaranteed by an excellent Gaussian random number (GRN) generator with high speed and an extended random period. In this paper, we propose to construct the Gaussian random number generator by using field-programmable gate array (FPGA), which is able to process large data in high speed. We also compare three algorithms of GRN generation:Box-Muller algorithm, polarization decision algorithm, and central limit algorithm. We demonstrate that the polarization decision algorithm implemented in FPGA requires less computing resources and also produces a high-quality GRN through the null hypothesis test.
KEYWORDSGaussian random numbers, quantum key distribution, field-programmable gate array, numerical modeling However, it is possible to obtain a pseudorandom quantum signal by a set of high-quality Gaussian random numbers (GRNs). 20 This requires the period of GRNs is long enough for guaranteeing the absolute security of QCK. On the other side, the speed of generating is also critical for effective communication between two parties. 21 Hence, an adequate Gaussian random source is economical and vital for continuous-variable quantum cryptography communication. 22 Whereas, the study of the Gaussian random number generator (GRNG) in continuous-variable QCK system is much complicated. Some excellent surveys of the GRNGs from the algorithmic perspective exist in the published literature of Thomas et al. 23 Thomas et al 23 compared their computational requirements and examined the quality. In this work, we choose three conventional algorithms for generating GRN: Box-Muller algorithm, 23,24 polarization decision algorithm, 23,25 and central limit algorithm. 23,26 The Box-Muller transform is one of the earliest exact transformation methods. 23 It produces a pair of GRNs from a couple of uniform numbers. The polar method is an exact method related to the Box-Muller transform and has a closely related 2-D graphical interpretation but uses a different approach to get the 2-D Gaussian distribution. 23,25 The probability density function describing the sum of multiple uniform random numbers (URNs) is obtained by convolving the constituent probability density function. Thus, by the central limit theorem, the probability density function of the sum of K URNs over the range (0, 1) will approximate a Gaussian distribution. Furthermore, Malik and Hemani 27 provide a potential capsulization of hardware GRNG architectures. In this work, we analyzed and compare these three algorithms of generating GRN for a continuous-variable quantum cryptography communication system. More importantly, we choose field-programmable gate array (FPGA) as hardware to construct GRNG architectures using the Box-Muller algorithm, polarization decision algorithm, and central limit algorithm. Generally, CPU executes instructions with...