Chaotic light secret communication system for enhancing secret key space based on photoelectric filtering feedback

[0035] Example one

[0036] Such as figure 1As shown, the embodiment of the present invention provides a chaotic light privacy communication system based on photoelectric filter feedback enhancing key space, including: ultra-radiation light emitting diode 1, first split element 4, first optical isolator 5a, second The optical isolator 5b, the first adjustable failure unit 6a, the second adjustable failure unit 6b, the transmitter, and the transmitter including the first semiconductor laser 7a, the second lighting element 8a, the first mirror 9a, The fourth substrate element 10a, the first photodetector 11a, the first tapered belt pass filter module 12a, and the first gain can be disposed, the receiver including the second semiconductor laser 7b, the third split element 8b, the second The mirror 9b, the fifth split element 10b, the second photodetector 11b, the second adjustable band pass filter module 12b, and the second gain can be modulated.

[0037] The broadband light signal emitted by the ultra-radiation light emitting diode 1 is divided into two channels through the first light receiving element 4, and the first semiconductor 6a is injected into the first semiconductor laser 7a through the first optical isolator 5a, and the first semiconductor laser 7a is injected. The second optical isolator 5b is injected into the second semiconductor laser 7b.

[0038] The chaotic light emitted by the first semiconductor laser 7a is divided into two channels through the second substance element 8a, and the first mirror 9a is reflected back to the first semiconductor laser 7a, and the other is divided into two channels through the fourth shot element 10a. The first photodetector 11a is detected and converted into a first electrical signal, and the first electrical signal is filtered by the first tapered pass filter module 12a, and the first gain can be amplified, and the first semiconductor laser 7a is forwarded. On the bias current, the other is used as a chaotic carrier for loading the signal.

[0039] The chaotic light emitted by the second semiconductor laser 7b is divided into two channels through the third substantive element 8b, and the second mirror 9b is reflected back to the second semiconductor laser 7b, and the other is divided into two channels through the fifth-point light element 10b. The second photodetector 11b detects and converted into a second electrical signal, the second electrical signal filters through the second adjustable band pass filter module 12b, and the second gain can be amplified, and the second semiconductor laser 7b is forwarded. On the bias current, the chaotic optical signal synchronized with the transmitter is used as a demodulated carrier for decoding the information loaded by the transmitter.

[0040] Specifically, in the present embodiment, the parameter setting of the first semiconductor laser 7a and the second semiconductor laser 7b is the same; the first adjustable failure unit 6a and the second adjustable failure unit 6b parameter setting are the same; the second split element 8a As in the third split element 8b parameter setting, the fourth split element 10a and the fifth split element 10b parameter setting are the same, and the substance ratio is 50:50. The first part of the mirror 9a and the second portion of the mirror 9b parameter setting are the same; the first photodetector 11a and the second photodetector 11b parameter setting are the same; the first tape pass filter module 12A and the second adjustable band pass filtering The module 12B parameter setting is the same; the first gain can be the same as the second gain can be the same.

[0041] Specifically, in the present embodiment, the first lighting element 4, the second lighting element 8a, the third shunt element 8b, the fourth shot element 10a, and the fifth split element 10b are 1 × 2 coupler. Its split ratio is 50:50.

[0042] In the present embodiment, the second substance element 8a, the first mirror 9a, and the fourth substrate element 10a are used to divide the chaotic light emitted by the first semiconductor laser 7a into three bouquets, and alternately return to the laser, and another Entered to the first photodetector 11a, the third beam as a chaotic carrier; the third splitting element 8b, the second mirror 9b, and the fifth split element 10b are used to divide the chaotic light emitted from the second semiconductor laser 7b into three bundles. And one of the laser is returned, and the other is incident to the second photodetector 11b, and the third beam is used as a demodulated carrier. As an alternative to the above embodiment, in the present embodiment, the first mirror 9a and the second mirror 9b may be a partially mirror that feeds a portion of the light emission feedback back to the corresponding coupler, and then feeds back the laser and the other part transmits Light can be used to load signals or for demodulation signals. At this time, the system can omit the fourth shot element 10a and the fifth split element 10b. Further, in the present embodiment, the second light-receiving element 8a and the fourth substance element 10a may be 1 × 3 fiber coupler, directly dividing the beam output from the laser into three channels, at this time, the system can also omit the fourth-spot light element. 10A and the fifth split element 10b.

[0043] In this embodiment, the first tonel pass filter module 12A and the second adjustable bandwidth filter module 12b are adjustable, so that in the synchronization performance of communication requirements, the bandpass filter center The frequency and the block parameters have a certain durable range. The different gain values ​​of the same gain tuning amplifier 13a and 13b further expand the adjustable range of parameters, further increasing the system's key space.

[0044] Specifically, the communication method of the present embodiment includes the following steps:

[0045] S1, adjust the parameters of the corresponding components of the transmitter and receiver, so that the transmission and reception is synchronized by the driving synchronization, that is, almost the same chaotic carrier;

[0046] S2, the message M (t) is loaded on the chaotic carrier output from the transmitter (Alice) by chaotic hidden manner, and transmitted to the receiving end (BOB) by a common link, and performs photovoltaic through the third photodetector 14a by the third photodetector 14a by a common link. The signal I1 = message M (T) + chaotic carrier obtained, in addition, the demodulated carrier signal output from the receiving end is the same as the chaotic carrier signal, and the signal obtained by photoelectric conversion by the fourth photodetector 14b is: I2 = Chaotic carrier, therefore, the signal of the third photodetector 14a and the fourth photodetector 14b is subtracted by the subtractor, i.e., the message M (T) is obtained.

[0047] Example 2

[0048] Such as figure 2 As shown, the second embodiment of the present invention provides a system based on photoelectric filter feedback enhancing chaotic light confidential communication key space, and the specific structure is substantially the same as that of the Example. Unlike the embodiment, in the present embodiment, the optical filter 2, an erbium-doped fiber amplifier 3; the ultra-radiation light-emitting diode 1 is transmitted by the wideband optical signal light filter 2, and the erbium-doped fiber amplifier 3 It is divided into two ways to the first light receiving element 4; the first semiconductor laser 7a is injected, and the first semiconductor laser 7a is injected, and the second optical isolator 5b, the second The second semiconductor laser 7b is injected after the adjustable failure unit 6b.

[0049] Specifically, in this embodiment, the second optical isolator 5a and the third optical isolator 5b parameter setting are the same.

[0050] In addition, if image 3 As shown, in the present embodiment, the first tape pass filter module 12a and the second adjustable band pass filter module 12b include a plurality of parallel-connected tunable band pass filters 12. By adjusting the center frequency and bandwidth parameters of the filter, the bandpass filter center frequency and the block parameters have a certain durable range in the synchronization performance of the communication requirements. The gain value of the different gain tuning amplifiers has further expanded the parameter adjustable range, which greatly expands the security key space of the system. Further, the plurality of tunable bandpass filter 12 is connected in parallel, so that the center frequency of a single filter, the physical key space consisting of the bandwidth increases as the number of filters increases into an exponential growth.

[0051] In summary, the present invention provides a system based on photoelectric filter feedback enhancing chaotic light confidential communication key space, using broadband noise signal as a driving source, which has a broadband characteristics, so that the eavesdropper cannot fully observe the time domain. Changes in turn cannot reconstruct the complete drive signal, which effectively enhances the security of communication. The system can be used as many parameters of the physical key, and the adjustable range is large. The main parameters include: adjustable bandwidth filter module, the center frequency of each filter, the bandwidth of each filter, the gain of the amplifier, the feedback strength of the outer light feedback ring, and the time delay of the photoelectric feedback ring. The present invention adopts an adjustable band pass filter module such that the center frequency of its single filter, the physical key space consisting of bandwidth as the number of filters increases into an exponential growth. The system has high security and can effectively resist direct filtering attacks and drive chaotic attacks. The invention is designed to be reasonable, effectively increases the key space in chaotic secure communication, improves the security of communication, and has better promotion application value.