High-speed Synchronized Physical Random Bit Generation Based On Chaotic System Of Drive-response Vertical-cavity Surface-emitting Lasers

With the development of the Internet and computer technology,information security technologies are becoming increasingly important.Random bit generation as one of core technologies of information security has attracted considerable attention.Generally,random number generators(RBG)are classified into two types:pseudorandom number generators and physical random number generators.Physical random bits(PRB)are widely used due to the advantages of non-periodicity,non-reproducibility and non-predictability.However,the rate of traditional PRB generators is usually limited to a Mbits/s level due to the bandwidth restricts,which cannot meet the rate requirements of high-speed secure communication network.Vertical-cavity surface-emitting lasers(VCSELs)can simultaneously lase at two orthogonally polarization components under appropriate parameter conditions,and wide-bandwidth chaotic signals can be obtained under appropriate external disturbances,us it as a source of entropy,high-speed physical random numbers can be obtained.Therefore,high-speed physical random bit generation based on chaotic output of VCSELs has important research value.In this paper,two VCSELs with optical injection and polarization-rotated optical feedback are used as legal users,we propose and numerically demonstrate a scheme for generating high-speed synchronized random bit sequences(SRBS).The chaotic outputs from the injection VCSEL(I-VCSEL)with polarization-rotated feedback are strongly injected into the driving VCSEL(D-VCSEL)to obtain bandwidth-enhanced chaos signals with two coexisting orthogonal polarization modes.The chaotic outputs of D-VCSEL are respectively injected to two legal VCSELs(A-VCSEL and B-VCSEL).By analyzing the dependences of the synchronization performances of chaotic outputs from the two legal VCSELs on the injection strength and frequency detuning,a optimized injection parameter space is determined.Using the synchronized chaotic outputs from the two legal VCSELs as physical entropy sources,after adopting 8 bitsADC and the m least significant bits(m-LSBs)extraction with logical exclusive-OR(XOR)post-processing the SRBS can be obtained.The bit error rate(BER)of two legal users generated SRBS is less than 0.01 in the optimal parameter area,which can effectively guarantee the security of generating SRBS between two legal users.By this scheme,the generated SRBS at a rate up to 400 Gbits/s can be achieved and the generated random bit sequences can pass all the 15 NIST statistics tests.In addition,the security of this scheme can be further ensured by a high-quality synchronization between A-VCSEL and B-VCSEL while relatively low-quality synchronization between D-VCSEL and A-VCSEL.