Research On Entropy Content And Generation Rate Improvement Of Continuous Variable Quantum Random Number Generator

The random code generator is the key to encryption technology,which fundamentally determines the privacy and security of the communication system and plays an irreplaceable role in the field of information security and financial security.In today's era of interconnection of all things and the explosion of information,facing the field of cryptography applications,a true random number generator provable by security information theory is of paramount importance.In the secure communication scheme,as the communication distance continues to increase and the rate continues to increase,the random number generator's random number production rate is increasingly demanding.In the quantum key distribution scheme,due to factors such as quantum decoherence,quantum transmission channel loss,and third-party eavesdropping,at least a random number yield of several Gbps or even 10 Gbps is needed to ensure the system's safe operation.We propose to increase the real-time yield of quantum random numbers by increasing the quantum noise entropy of continuous variable quantum random number and parallel quantum entropy source extraction methods.First,the effects of various factors such as the detection gain,background gain,ADC sampling range,and side information in the quantum detection system and the random number variable quantization system on the quantum entropy content should be studied.It is proposed to effectively increase the system quantum entropy content by increasing the background gain under the premise of optimizing the quantization dynamic range.Furthermore,the method of using chaos sensitivity to amplify quantum shot noise is explored,and the signal-to-noise ratio of the quantum random number entropy source is increased to increase the system quantum entropy content.Finally,the method of parallel extraction of three high-frequency sideband quantum states of the quantum vacuum state as the source of entropy within the bandwidth of the balanced homodyne detector is used to increase the yield speed of quantum random numbers exponentially.The real-time yield of 8.25Gbps quantum random number generator has been realized experimentally.Taking advantage of the infinite bandwidth of vacuum quantum fluctuations and the independence of different frequency modes,we extract multiple fluctuations of vacuum quantum mode components with different center frequencies as an entropy source to generate quantum random numbers in parallel.Fully use the advantages of FPGA parallel algorithm,based on a single FPGA,real-time parallel post-processing of multiple quantum random numbers,efficient use of hardware logic resources.The scheme has stable system,remarkable integration prospect and strong expansibility,and provides a high-speed scheme for continuous variable quantum random number generator.