TW201907681A - Wireless optical communication method for implementing image encryption and decryption capable of ensuring the safety of image transmission in wireless optical communication - Google Patents

Abstract

Provided is a wireless optical communication method for implementing image encryption and decryption, which includes the steps of: using an encryption unit to generate a random index value for selecting an encryption pairing combination, which indicates each input end of a transmitting end logic input/output unit and its correspondingly matched output end, from N! pairing combinations; when the transmitting end logic input/output unit receives a corresponding image bit data from the N image bit data through the input end, outputting the corresponding image bit data to the output end matched with the input end according to the encryption pairing combination; using each modulator to perform modulation according to the inputted image bit data and the inputted carrier set so as to generate a light modulation signal; and using an optical multiplexing unit to perform a multiplexing process for generating an optical multiplexing output signal for output to a wireless optical communication device at a receiving end.

Description

Wireless optical communication method for realizing image encryption and decryption

The invention relates to a wireless optical communication method, in particular to a wireless optical communication method for realizing image encryption and decryption.

With the rapid development of wireless networks, the load of data volume is increasing, people are beginning to pursue more flexible and high-speed wireless network services, but it has also become the main target of eavesdropper attacks. Because wireless optical communication has a wide bandwidth and can carry more messages, it has become one of the important technologies of wireless network communication in recent years. Therefore, the security of wireless optical communication has attracted more scholars' attention. Taking image transmission as an example, because the amount of data to be transmitted is too large, when a telecom service provider or equipment manufacturer considers the transmission efficiency, when the encryption program is executed on the application layer, only part of the data is encrypted, and the information is reduced. The security of wireless optical communication during transmission.

In view of this, how to provide a solution that can solve the aforementioned problems is a technical problem that needs to be solved in the field.

Therefore, the object of the present invention is to provide a wireless optical communication method for realizing image encryption and decryption, so as to solve the problem that only the partial encryption can be performed on the application layer, and the security of the wireless optical communication in transmitting the image is reduced. Dilemma.

Therefore, the wireless optical communication method for realizing image encryption and decryption according to the present invention is implemented by a transmitting wireless optical communication device and a receiving wireless optical communication device in a predetermined wireless optical communication architecture; the transmitting wireless optical communication device The invention comprises an image compression unit, a light source generating unit, an optical filtering unit having N filters and electrically connecting the light source generating unit, an encryption unit, a microprocessor, N input terminals and N output terminals. And a transmitting end logic input and output unit electrically connected to the image compressing unit and the encrypting unit, a modulation unit having N modulators and electrically connected to the transmitting end logic input and output unit, and a modulation unit Connected light multiplex unit.

The image compression unit may compress and encode the N source image data to generate N image bit data, and the light source generating unit may provide M light source carriers with different wavelengths.

The N filters may be input through the M light source carriers to generate N carrier groups; wherein each carrier group has at least one light source carrier, and the N modulators and the N filters respectively And the N output ends of the logic input/output unit of the transmitting end are electrically connected, wherein M≥N and N≥3;

The method comprises a step (A), a step (B), a step (C), a step (D), and a step (E).

In the step (A), the cryptographic unit is configured to indicate the N input terminals and the N output terminals according to the N input terminals and the N output terminals of the logic input/output unit of the transmitting end. N! Pairing combinations of the opposing relationship.

In the step (B), the cryptographic unit generates a random index value, and selects an encrypted pairing combination from the N! pairing combinations according to the randomness index value, and transmits the random index value to The decrypting unit and the transmitting end logic input and output unit, wherein the encrypted pairing combination is used to indicate each input end of the transmitting end logic input and output unit and its corresponding mating output end.

In the step (C), for each input end of the transmitting logic input/output unit, when the microprocessor receives one of the N image bit data from the image compressing unit via the input end Corresponding image bit data, the microprocessor outputs the corresponding image bit data to the output end of the transmitting logic input/output unit matched by the input terminal according to the encrypted pairing combination.

In the step (D), for each modulator, the modulator is based on the image bit data outputted from the output end of the logic input/output unit connected to the transmitting end and the carrier group generated by the connected filter. Modulation is performed to generate and output a light modulation signal to the optical multiplexing unit.

In the step (E), the optical multiplexing unit performs multiplexing processing on the N optical modulation signals according to the predetermined wireless optical communication architecture to generate an optical multiplexing output signal and outputs the optical optical communication to the receiving end. Device.

The effect of the present invention is that the present invention utilizes the wavelength-hopping or coded wavelength hopping encryption performance of multiple light source carriers on the physical layer to solve the problem that the image can only be partially performed on the application layer. Encryption reduces the security of wireless optical communications when transmitting images.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

1 is a first embodiment of a wireless optical communication method for implementing image encryption and decryption according to the present invention. The wireless optical communication method for implementing image encryption and decryption is implemented by a transmitting wireless optical communication device 1 and a The receiving wireless optical communication device 2 is implemented in a predetermined wireless optical communication architecture. In the first embodiment, the predetermined wireless optical communication architecture is Wavelength Division Multiplexing (WDM).

The transmitting end wireless optical communication device 1 includes an image compression unit 11, a light source generating unit 12, an optical filtering unit 15 electrically connected to the light source generating unit 12, an encryption unit 16, an image compression unit 11 and the encryption. a transmitting end logic input/output unit 13 electrically connected to the unit 16, a modulation unit 14 electrically connected to the transmitting end logic input and output unit 13, an optical multiplexing unit 17 electrically connected to the modulation unit 14, and a The optical multiplexing unit 17 is electrically coupled to the transmitting end collimator 18. The transmitting end logic input and output unit 13 has a microprocessor 131, N input terminals and N output terminals (not shown). The modulation unit 14 has N modulators (not shown), and the optical filter The unit 15 has N filters (not shown); wherein the N modulators are electrically connected to the N filters and the N outputs of the transmitter logic input/output unit 13, respectively, and N ≥ 2.

The receiving end wireless optical communication device 2 has a receiving end collimator 23, a decrypting unit 21, an optical multiplexing unit 22 electrically connected to the receiving end collimator 23, and a photo demultiplexing unit 22 a demodulation unit 25 electrically connected, a receiving logic input/output unit 24 electrically connected to the decrypting unit 21 and the demodulation unit 25, and an image restoration unit electrically connected to the receiving logic input/output unit 24 26; the receiving end logic input and output unit 24 has a microprocessor 241, N inputs and N outputs (not shown), the demodulation unit 25 has N demodulators (not shown) Each demodulation is electrically coupled to each input of the receiving logic input and output unit 24. In the first embodiment, the transmitting end logic input and output unit 13 and the receiving end logic input and output unit 24 are programmable N×N electronic switches, which can be controlled to change the corresponding internal switch contacts ( a cross-on or bar-off state for varying the input-output cooperation relationship of the N N input terminals and the N output terminals of the transmit logic input/output unit 13 and The N input and the N input ends of the receiving logic input/output unit 24 and the input and output coordination functions of the N output terminals. In addition, the image compression unit 11, the image restoration unit 26, the encryption unit 16, and the decryption unit 21 can be realized by electronic components having computing capabilities such as embedded system components and digital circuits.

The image compression unit 11 receives the N source image data User#1~User#N transmitted from the outside, and compresses and encodes the N source image materials User#1~User#N (for example, H.264 or H). The compression coding technique of .265 is to sequentially generate N image bit data U ₁ ~U _N and sequentially transfer N image bit data to the corresponding N input terminals of the corresponding logic input/output unit 13 of the transmitting end. In the first embodiment, each image bit material U ₁ /U _{2 . . .} /U _N can represent, for example, a frame image, but not limited thereto, and can also represent a multi-frame image. The N source image data User#1~User#N are unprocessed original image formats.

The light source generating unit 12 generates N light source carriers λ ₁ to λ _N having unequal wavelengths, and then transmits them to the N filters of the optical filtering unit 15 respectively; then, the N filters are received according to the received The N light source carriers λ ₁ ~λ _N to generate N carrier groups; in the first embodiment, each carrier group has a specific wavelength of the light source carrier λ ₁ /λ ₂ ... λ _N-1 /λ _N , that is, the wavelengths of the N light source carriers λ ₁ ~ λ _N output by the N filters are different from each other, wherein N = 2 ⁿ , n ≥ 2; each filter may be a spatial light modulator Realized by optical components such as (spatial light modulator, SLM) or fiber Bragg grating (FBG).

First, the cryptographic unit 16 is configured to indicate the N input terminals and the N output terminals according to the N input terminals and the N output terminals of the logic input/output unit 13 of the transmitting end ( The N! pairing combination of the relationship; wherein the encrypted pairing combination is used to indicate each input end of the transmitting end logic input and output unit 13 and its corresponding mating output end, that is, each input end exactly matches an output The opposite relationship. Then, the encryption unit 16 generates a random index value, and selects an encrypted pairing combination from the N! pairing combinations according to the randomness index value, and transmits the randomness index value to the decrypting unit 21 and The transmitting end logic inputs and outputs the unit 13.

It is worth mentioning that each pairing combination corresponds to a matrix pattern, each matrix type is N×N and each of the matrix elements and only one element of each column element is '1' and the remaining elements are ' a matrix of 0', and N columns in each matrix correspond to the N inputs of the logic input/output unit 13 of the transmitting end, and N rows in each matrix correspond to the N of the logical input/output unit 13 of the transmitting end Outputs; in addition, the N! pairing combinations are a collection of all possibilities for the matrix pattern , i, j = 1, 2, 3..., N; assuming that N = 3, a total of 3! pairing combinations, for example, the matrix types of the sets of all the possibilities are: , , , , and , a total of six aspects; when the encryption pairing is In the matrix type, wherein the matrix element TR ₁₂ =1 in the matrix pattern can indicate that any one of the signal data is input from the first input end of the logic input/output unit 13 of the transmitting end, and only correspondingly cooperates The second output is output; TR ₂₃ =1, which means that any one of the signal data is input from the second input of the logic input/output unit 13 of the transmitting end, and only the corresponding output of the third output is matched; TR ₃₁ =1, it can mean that any one of the signal data is input from the third input of the logic input/output unit 13 of the transmitting end, and only the corresponding output is matched by the first output. It is also worth mentioning that if the image compression unit 11 is at different time points t _k , k=1, 2, 3..., 30 (here 30 is assumed, but not limited thereto), different Ns are sequentially arranged. The image bit data is transmitted to the N input terminals of the corresponding logic input/output unit 13 of the transmitting end, and the microprocessor 131 for implementing the wireless optical communication method for image encryption and decryption is outputted each time. Encrypted pairing combination used by image bit data U ₁ /U _2... /U _N (that is, representing each frame or multi-frame image) to the output of the transmitter-side logic input-output unit to which the input is coupled the re are new random index values from such re-N! pairing combination (i.e., each at a different time point t _k of It is selected to avoid that after the encrypted pairing combination is cracked, the image bit data transmitted later can be successfully decrypted. In addition, for each matrix pattern, the manner is generated as follows: First, the encryption unit 16 generates a random real number r ₁ (t _k ) through a Pseudo-random number generator (PRNG). , r ₂ (t _k ),...r _N (t _k ) and the random number sequence of elements of mutually different and random values R _real ={r ₁ (t _k ),r ₂ (t _k ), ...r _N (t _k )}, k=1, 2, 3..., 30, and the random number sequence is assigned to the randomness index value. In the first embodiment, the virtual random number The generator is configured to generate a sequence of non-repeating random numbers at fixed intervals (ie, different time points t _k ); then, the encryption unit 16 numerically converts the random number sequence by a mapping function O _TR to The N random real numbers are respectively assigned to a positive integer sequence code having a value of 1 to N according to their numerical values. For example, it is assumed that N=4 and the random number sequence is: {0.6, 0.8, 0.9, 0.3 }, the value conversion is performed by the mapping function O _TR and corresponds to O _TR (t _k )= {2, 3, 4, 1}, wherein the positive integer sequence code corresponding to the minimum value of 0.3 in the random number sequence Positive for 1 and maximum 0.9 Code sequence number is 4; and _{O TR (t k) = {} 2, 3, 4, 1} as a point of time t randomness index value _k, which contains a series consisting of four elements, wherein each The elements represent mutually exclusive integer values with a random order value; then, the encryption unit 16 replaces the mapping function with a permutation matrix, ie: . In the above example, the permutation matrix Pπ corresponding to the permutation π = O _TR (t _k )= {2, 3, 4, 1} is expressed as:

In other words, the set matrix can be correspondingly obtained by the permutation process of O _TR (t _k )={ 2, 3, 4, 1} One of the matrix types.

Since each element in the mapping function sequence is random, each matrix pattern is also random.

Then, for each input end of the transmitting end logic input/output unit 13, when the microprocessor 131 receives the N pieces of image bit data U ₁ ~U _N from the image compressing unit 11 via the input end, When one of the corresponding image bit data, that is, U ₁ ~U _N , the microprocessor 131 outputs the corresponding image bit data U ₁ ~U _N to the input terminal according to the encrypted pairing combination The output end of the mating logic input/output unit 13 is matched.

For each modulator, the modulator outputs image bit data U ₁ /U ₂ ... U _N-1 /U _N and the connected filter according to the output end of the logic input/output unit 13 connected to the transmitting end. The generated carrier group λ ₁ /λ ₂ ... λ _N-1 /λ _N is modulated to generate and output a light modulation signal U _X1 (λ ₁ )/U _X2 (λ ₂ )...U _XN-1 (λ _N-1 ) / U _XN (λ _N ) is transmitted to the optical multiplexing unit 17 in parallel. In the first embodiment, each of the modulator systems is modulated by an on-off keying technique; wherein, since the image bit data U ₁ ~U _N can be based on the transmitting end The logic input/output unit 13 converts its input and output relationship so that in each modulation, the image bit data U ₁ ~U _{N are} not all matched with the same carrier group λ ₁ ~λ _N , thereby forming a jump wave ( Wavelength hopping) mechanism. For example, this time The matrix pattern is used as the encryption pairing combination to output the corresponding image bit data U ₁ ~U _N to the output end of the transmitting end logic input/output unit 13 matched by the input terminal, U ₁ , U ₂ , The output order of U ₃ and U ₄ will become U ₄ , U ₁ , U ₂ , U ₃ , and then, the modulator U ₄ corresponding to the filter generating the λ ₁ carrier group is connected to generate the optical modulation signal U. _X1 (λ ₁ ), connected to the modulator U ₁ corresponding to the filter generating the λ ₂ carrier group to generate the optical modulation signal U _X2 (λ ₂ ), and connected to the modulation corresponding to the filter generating the λ ₃ carrier group Transducing U ₂ to generate a light modulation signal U _X3 (λ ₃ ), connecting a modulator U ₃ corresponding to a filter generating a λ ₄ carrier group to generate a light modulation signal U _X4 (λ ₄ ), Second The matrix pattern is used as the encryption pairing combination to output the corresponding image bit data U ₁ ~U _N to the output end of the transmitting end logic input/output unit 13 to which the input end is matched, then U ₁ , U ₂ , The output order of U ₃ and U ₄ will become U ₁ , U ₄ , U ₂ , U ₃ , and then, the modulator U ₁ corresponding to the filter generating the λ ₁ carrier group is connected to generate the optical modulation signal U. _X1 (λ ₁ ), connected to the modulator U ₄ corresponding to the filter generating the λ ₂ carrier group to generate the optical modulation signal U _X2 (λ ₂ ), and connected to the modulation corresponding to the filter generating the λ ₃ carrier group Modulating U ₂ to generate a light modulation signal U _X3 (λ ₃ ), connecting a modulator U ₃ corresponding to a filter generating a λ ₄ carrier group to generate a light modulation signal U _X4 (λ ₄ ), First, the image bit data U ₁ ~U _N and the next image bit data U ₁ ~U _{N are} not all matched with the same carrier group λ ₁ ~λ _N , so a jumping wave mechanism is formed.

The optical multiplexing unit 17 performs optical multiplexing and multiplexing on the N optical modulation signals U _X1 (λ ₁ )~Ux _N (λ _N ) according to the wavelength division multiplexing technology to generate an optical multiplexing output signal ( That is, the N optical modulation signals (U _X1 (λ ₁ )~U _XN (λ _N )) after the multiplex convergence are focused by the emitter collimator 18 and then parallel incident on the The wireless optical channel is output to the receiving end collimator 23 of the receiving end wireless optical communication device 2. In the first embodiment, the N optical elements such as an arrayed waveguide fiber grating or a Bragg fiber grating may be used. The modulation signal U _X1 (λ ₁ )~U _XN (λ _N ) performs optical splitting multiplexing, but is not limited thereto.

After the receiving end collimator 23 of the receiving end wireless optical communication device 2 receives the optical multiplexing output signal, the optical multiplexing output signal is transmitted to the optical multiplexing multiplex unit 22; synchronously, the decrypting unit 21, according to the random index value transmitted by the encryption unit 16, selecting one of the N! pairing combinations to decrypt the pairing combination and transmitting to the receiving logic input/output unit 24; wherein The decryption pairing combination is used to indicate each input end of the receiving end logic input and output unit 24 and its corresponding mated output end. In the first embodiment, the encryption pair is combined to correspond to the matrix pattern set described above. One of a total of N! possibilities, and in order to decrypt the image bit data U ₁ ~U _N via the jump wave, the matrix pattern corresponding to the decrypted pairing combination is combined with the encryption pair The corresponding matrix patterns are mutually transposed; for example, assuming that at N=4 time point t _k , the matrix pattern corresponding to the encrypted pairing combination is , the matrix pattern corresponding to the decrypted pairing combination is (which is, The transposed matrix), the product of the two matrices constitutes an identity matrix.

The photo-multiplexing unit 22 performs multiplex processing on the optical multiplex output signal according to the wavelength division multiplexing technology to generate the N sets of photo-demultiplexed signals U _X1 (λ ₁ )~U _XN (λ _N And correspondingly input to the N demodulation transformers. In the first embodiment, the photo-demultiplexing unit 22 can be demultiplexed by a 1×N concentrated arrayed waveguide fiber grating (AWG) or N columns of Bragg fiber gratings (FBG). Work, but not limited to this. At this time, due to the scrambling effect of the skipping wave, it is impossible to surely know which of the carrier groups λ ₁ to λ _N which are one-to-one corresponding to the modulated image bit data U ₁ to U _N .

The N demodulation transformers respectively demodulate the N sets of photo-demultiplexed signals U _X1 (λ ₁ )~U _XN (λ _N ) to generate N optical demodulation signals U _X1 -U _XN , and then input the N optical demodulation signals U _X1 ~ U _XN to the input terminals corresponding to the receiving logic input and output unit 24 respectively. In the first embodiment, each demodulator can be demodulated by a photodetector, but not limited thereto; at this time, it is still impossible to know the N optical demodulations. The variable signals U _X1 ~U _XN , whether or not the image bit data U ₁ ~U _N are sequentially _aligned .

For each input end of the receiving-side logic input-output unit 24, when the microprocessor 241 receives the N optical demodulation signals U _X1 -U from the N demodulators via the input terminal _When one of the _XNs corresponds to the optical demodulation signal, the microprocessor 241 outputs the corresponding optical demodulation signal to the receiving logic input/output unit 24 corresponding to the input terminal according to the decrypted pairing combination. The output end obtains a corresponding image bit material U ₁ ~U _N .

The image restoration unit 26 restores the image bit data U ₁ ~U _N to generate the source image data User#1~User#N, and correctly restores the source image data User#1. ~User#N The signal in its original image format. It is worth mentioning that due to the decryption pairing combination Corresponding to the encryption pairing The product of the two can form a unit matrix, so the source image data User#1~User#N after the jump wave can be decrypted and restored.

2 is a second embodiment of a wireless optical communication method for implementing image encryption and decryption according to the present invention. The wireless optical communication method for implementing image encryption and decryption is provided by a transmitting wireless optical communication device 1 and a transmitter. The receiving wireless optical communication device 2 is implemented in a predetermined wireless optical communication architecture. In the second embodiment, the predetermined wireless optical communication architecture is Optical Code Division Multiple Access (OCDMA). It should be noted that the transmitting end wireless optical communication device 1 and the receiving end wireless optical communication device 2 in the second embodiment are similar to the transmitting wireless optical communication device 1 in the first embodiment. The receiving end wireless optical communication device 2, therefore, the following similar content will not be described again.

The transmitting end wireless optical communication device 1 includes an image compressing unit 11, a light source generating unit 12, an optical filtering unit 15 electrically connected to the light source generating unit 12, an encrypting unit 16, a and the image compressing unit 11 and the a transmitting logic input/output unit 13 electrically connected to the encryption unit 16 , a modulation unit 14 electrically connected to the transmitting logic input and output unit 13 , an optical multiplexing unit 17 electrically connected to the modulation unit 14 , and a An emitter collimator 18 electrically coupled to the optical multiplexing unit 17. The transmitting end logic input and output unit 13 has a microprocessor 131, N input terminals and N output terminals (not shown). The modulation unit 14 has N modulators (not shown), and the optical filter The unit 15 has N filters (not shown); wherein the N modulators are electrically connected to the N filters and the N outputs of the transmitter logic input/output unit 13, respectively, and N ≥ 3.

The receiving end wireless optical communication device 2 has a receiving end collimator 23, a decrypting unit 21, an optical multiplexing unit 22 electrically connected to the receiving end collimator 23, and a photo demultiplexing unit 22 a demodulation unit 25 electrically connected, a receiving logic input/output unit 24 electrically connected to the decrypting unit 21 and the demodulation unit 25, and an image restoration unit electrically connected to the receiving logic input/output unit 24 26; the receiving end logic input and output unit 24 has a microprocessor 241, N inputs and N outputs (not shown), the demodulation unit 25 has N demodulators (not shown) Each demodulation is electrically coupled to each input of the receiving logic input and output unit 24. In the second embodiment, the transmitting logic input/output unit 13 and the receiving logic input and output unit 24 are programmable N×N electronic switches, which can be controlled to change the internal switch contacts or a state of being disconnected to change an input/output cooperation relationship between the N Nth input terminals and the N output terminals of the logic input/output unit 13 of the transmitting end, and the logic input/output unit 24 of the receiving end The input and output coordination relationship of the N N input terminals and the N output terminals. In addition, the image compression unit 11, the image restoration unit 26, the encryption unit 16, and the decryption unit 21 can be realized by electronic components having computing capabilities such as embedded system components and digital circuits.

The image compression unit 11 receives the N source image data User#1~User#N transmitted from the outside, and compresses and encodes the N source image materials User#1~User#N (for example, H.264 or H). The compression coding technique of .265 is to sequentially generate N image bit data U ₁ ~U _N and sequentially transfer N image bit data to the corresponding N input terminals of the corresponding logic input/output unit 13 of the transmitting end. In the second embodiment, each of the image bit data U ₁ /U _{2 . . .} /U _N represents one or more frames of images, and the N source image data User#1~User#N are not The processed original image format.

The light source generating unit 12 generates M light source carriers λ ₁ ~ λ _M having unequal wavelengths, and respectively transmits them to the N filters of the optical filtering unit 15; then, the N filters are received according to the received The M light source carriers λ ₁ ~ λ _M to generate N carrier groups, where M ≥ 4; in the second embodiment, each carrier group has M different wavelengths of light source carriers λ ₁ ~ λ _M Each filter can be implemented by an optical component such as a spatial light modulator or a Bragg fiber grating.

First, the cryptographic unit 16 obtains the relationship between the N input terminals and the N output terminals according to the N input terminals and the N output terminals of the logic input/output unit 13 of the transmitting end. The N! pairing combination; wherein the encrypted pairing combination is used to indicate each input end of the transmitting end logic input and output unit 13 and its corresponding mating output end, that is, each input end is exactly matched with an output end pair Shooting relationship. Then, the encryption unit 16 generates a random index value, and selects an encrypted pairing combination from the N! pairing combinations according to the randomness index value, and transmits the randomness index value to the decrypting unit 21 and The transmitting end logic inputs and outputs the unit 13.

Wherein, each encryption pair combination corresponds to a matrix pattern, and the N! pairing combination is a set of all possibilities of the matrix pattern , i, j = 1, 2, ... N; the technical content of the matrix pattern is the same as that of the first embodiment, and will not be described herein.

Then, for each input end of the transmitting end logic input/output unit 13, when the microprocessor 131 receives the N pieces of image bit data U ₁ ~U _N from the image compressing unit 11 via the input end, When one of the corresponding image bit data, that is, U ₁ ~U _N , the microprocessor 131 outputs the corresponding image bit data U ₁ ~U _N to the input terminal according to the encrypted pairing combination The output end of the mating logic input/output unit 13 is matched.

For each modulator, the modulator outputs image bit data U ₁ /U ₂ ... U _N-1 /U _N and the connected filter according to the output end of the logic input/output unit 13 connected to the transmitting end. The generated carrier group λ ₁ ~ λ _M is modulated to generate and output a light modulation signal U _X1 (λ ₁ ~ λ _M ) / U _X2 (λ ₁ ~ λ _M ) / U _X3 (λ ₁ ~ λ _M )...U _XN-1 (λ ₁ ~λ _M )/U _XN (λ ₁ ~λ _M ) are transmitted to the optical multiplexing unit 17 in parallel. In the second embodiment, each of the modulator systems is modulated by an amplitude keying technique; it is worth mentioning that the image bit data U ₁ ~U _N can be input according to the logic of the transmitting end. The output unit 13 converts its input and output relationships.

The optical multiplexing unit 17 performs orthogonal coding of the N optical modulation signals U _X1 (λ ₁ ~λ _M )~U _XN (λ ₁ ~λ _M ) according to the optical code division multiple access technology to complete Processing, and generating an optical multiplex output signal U _X1 (C ₁ )~U _XN (C _N ) (wherein C ₁ ~C _{N are} encoded signals of the different wavelengths of the light source carrier λ ₁ ~λ _M The orthogonal optical frequency domain code is focused by the transmitting end collimator 18 and then parallelly incident on a wireless optical channel and output to the receiving end collimator 23 of the receiving end wireless optical communication device 2. In the second embodiment, the optical multiplexing unit 17 can adjust the N optical modulation signals U _X1 by using an N×N concentrated array waveguide fiber grating and using a maximum length sequence (MLS). (λ ₁ ~ λ _M )~U _XN (λ ₁ ~λ _M ) performing orthogonal coding, or N-divided Bragg fiber gratings according to Hadamard code to adjust the N optical modulation signals U _X1 (λ ₁ ~λ _M )~U _XN (λ ₁ ~λ _M ) is orthogonally encoded and then generated by an optical coupler (not shown) to generate the optical multiplex output signal U _X1 (C ₁ )~ U _XN (C _N ), since the image bit data U ₁ ~U _N can be converted according to the input and output relationship of the logic input and output unit 13 of the transmitting end, each time through modulation, encoding and completion of multiplexing processing The latter image bit data U ₁ ~U _{N are} not all matched with the same optical frequency domain code to form a coded wavelength hopping mechanism; it is worth mentioning that when using the maximum length sequence for orthogonal coding When M=N=2 ⁿ -1, n≥2; when orthogonal coding is performed using the Hada code, M=N+1=2 ⁿ , n≥2.

When the receiving end collimator 23 of the receiving end wireless optical communication device 2 receives the optical multiplexing output signal U _X1 (C ₁ )~U _XN (C _N ), it passes through a splitter (not shown) Transmitting the optical multiplexing output signal U _X1 (C ₁ )~U _XN (C _N ) to the optical multiplexing multiplex unit 22; synchronously, the randomness transmitted by the decrypting unit 21 according to the encryption unit 16 The index value is selected from the N! pairing combinations to decrypt the pairing combination corresponding to one of the encrypted pairing combinations and transmitted to the receiving end logic input and output unit 24; wherein the decrypting pairing combination is used to indicate the receiving end logic input and output Each input of unit 24 and its corresponding mated output. In the second embodiment, the same as the first embodiment, since the encrypted pairing combination is corresponding to the matrix pattern set described above. One of a total of N! possibilities, and in order to decrypt the image bit data U ₁ ~U _N after the coded wavelength hopping, the decrypted pairing combination corresponds The matrix patterns corresponding to the matrix type and the encryption pairing are mutually transposed.

The photo-multiplexing unit 22 performs orthogonal decoding on the optical multiplexing output signals U _X1 (C ₁ )~U _XN (C _N ) according to the code division multiple access technology to complete the demultiplexing process, and generates the same Group N photolysis multiplex signal U _X1 (C ₁ ), U _X1 ( )~U _XN (C _N ), U _XN ( And correspondingly input to the N demodulation transformers. In the second embodiment, the photo-demultiplexing unit 22 can adopt two Ns in a centralized manner. An original and complementary arrayed waveguide fiber grating decoder writes a maximum length code (M-sequence code) in an orthogonal code, or an orthogonal code written in an N-pair complementary and complementary Bragg fiber grating. Hada code performs multiplex processing, but not limited to this. At this time, due to the disturbance of the optical frequency hopping code, it is impossible to know whether the image bit metadata U ₁ ~U _N correctly corresponds to (C ₁ , ~(C _N , Which one of them carries the optical frequency domain code.

The N demodulation transformers respectively divide the N sets of photo-demultiplexed signals U _X1 (C ₁ ), U _X1 ( )~U _XN (C _N ), U _XN ( Demodulating to generate N optical demodulation signals U _X1 ~ U _XN , and then inputting the N optical demodulation signals U _X1 ~ U _XN to the receiving end logic input and output unit 24 respectively The inputs. In the second embodiment, each demodulator can be demodulated by a balanced photodetector, but not limited thereto; at this time, the N lights cannot be surely known. Demodulation of the variable signal U _X1 ~ U _XN , whether or not the corresponding image bit data U ₁ ~ U _N are sequentially _matched .

For each input end of the receiving-side logic input-output unit 24, when the microprocessor 241 receives the N optical demodulation signals U _X1 -U from the N demodulators via the input terminal _When one of the _XNs corresponds to the optical demodulation signal (ie, one of U _X1 ~ U _XN ), the microprocessor 241 outputs the corresponding optical demodulation signal to the input terminal according to the decrypted pairing combination. The output of the receiving end logic input/output unit 24 is matched to obtain a corresponding image bit material U ₁ ~U _N .

The image restoration unit 26 restores the image bit data U ₁ ~U _N to generate the source image data User#1~User#N, and correctly restores the source image data User#1 ~User#N The signal in its original image format. It is worth mentioning that due to the decryption pairing combination Corresponding to the encryption pairing The product of the two can form a unit matrix, so that the source image data User#1~User#N via the coded wavelength hopping can be decrypted and restored.

In summary, the present invention selects the encrypted pairing combination from the N! pairing combinations for the wavelength-multiplexed communication of the source image data User#1~User#N after the transmission encryption process. Under the framework, master the wavelength hopping pattern or master the coded wavelength hopping pattern under the optical code division multiple access communication architecture, and then combine with the decryption pair in the subsequent decryption. Correct matching of autocorrelation to interpret the higher peak signal-to-noise ratio (PSNR) of the N source image data, and then restore the source image data User#1~ User#N; on the other hand, in response to a larger amount of video stream in the future, the present invention uses the scrambling or optical frequency hopping encryption performance of multiple light source carriers on the physical layer to solve the problem that the image can only be performed on the application layer. Partial encryption reduces the security of wireless optical communication when transmitting images, so the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the simple equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still Within the scope of the invention patent.

Other features and effects of the present invention will be apparent from the following description of the drawings. FIG. 1 is a block diagram illustrating a transmitting wireless optical communication device and a receiving wireless optical communication device of the present invention. A first embodiment of the wireless optical communication using the wavelength division multiplexing technology; and FIG. 2 is a block diagram illustrating the wireless optical communication device of the transmitting end and the wireless optical communication device of the receiving end using the optical code division multiple access technology A second embodiment of wireless optical communication.

Claims (9)

A wireless optical communication method for realizing image encryption and decryption is implemented by a transmitting wireless optical communication device and a receiving wireless optical communication device in a predetermined wireless optical communication architecture, wherein the transmitting wireless optical communication device includes an image a compression unit, a light source generating unit, an optical filtering unit having N filters and electrically connected to the light source generating unit, an encryption unit, a microprocessor, N inputs, and N outputs, and The image compression unit and the transmitting end logic input and output unit electrically connected to the encryption unit, a modulation unit having N modulators and electrically connected to the transmitting logic input and output unit, and a light electrically connected to the modulation unit The multiplex unit, wherein the image compression unit compresses and encodes the N source image data to generate N image bit data, and the light source generating unit can provide M wavelength unequal light source carriers, and the N filters The device may generate N carrier groups via the inputs of the M light source carriers, wherein each carrier group has at least one light source carrier, and the N modulators respectively The N filters and the N output terminals of the logic input/output unit of the transmitting end are electrically connected, wherein M≥N and N≥3, the method comprises the following steps: (A) the cryptographic unit is configured according to the transmitting end logic The N input terminals and the N output terminals of the input/output unit obtain N! pairing combinations for indicating the relationship between the N input terminals and the N output terminals; (B) the encryption The unit generates a random index value, and selects an encrypted pairing combination from the N! pairing combinations according to the randomness index value, and transmits the randomness index value to the decrypting unit and the transmitting end logic input and output. a unit, wherein the encrypted pairing combination is used to indicate each input end of the transmitting end logic input and output unit and its corresponding mating output end; (C) for each input end of the transmitting end logic input and output unit, when When the microprocessor receives the image bit data corresponding to one of the N pieces of image bit data from the image compression unit via the input end, the microprocessor selects the corresponding image bit according to the encrypted pairing combination. Metadata Output to the output end of the transmitter logic input/output unit matched with the input terminal; (D) for each modulator, the modulator outputs an image bit according to the output end of the logic input/output unit connected to the transmitter terminal The metadata and the carrier group generated by the connected filter are modulated to generate and output a light modulation signal to the optical multiplexing unit; and (E) the optical multiplexing unit is configured according to the predetermined wireless optical communication architecture The N optical modulation signals are multiplexed to generate an optical multiplexing output signal and output to the receiving end wireless optical communication device. The wireless optical communication method of claim 1, wherein the receiving wireless optical communication device has a decryption unit, a photo-demultiplexing unit, a demodulation unit having N demodulators, and the a receiving end logic input and output unit electrically connected to the decrypting unit and an image reducing unit electrically connected to the receiving end logic input and output unit, the receiving end logic input and output unit having a microprocessor, N input ends and N output ends, Each demodulation transformer is electrically connected to each input end of the receiving logic input/output unit, and the wireless optical communication method further comprises the following steps: (F) the random index value transmitted by the decryption unit according to the encryption unit Selecting one of the paired encryption pairings to decrypt the pairing combination from the N! pairing combinations and transmitting to the receiving end logic input and output unit, wherein the decrypting pairing combination is used to indicate each of the receiving end logic input and output units An input end and a corresponding mating output end thereof; (G) the photolysis multiplex unit demultiplexing the optical multiplex output signal according to the predetermined wireless optical communication architecture Generating the N sets of photodemultiplexed signals and correspondingly inputting to the N demodulators; (H) the N demodulators respectively demodulating the N sets of optically demultiplexed signals Changing to generate N optical demodulation signals, and then inputting the N optical demodulation signals to the input terminals corresponding to the logic input/output units of the receiving end; (I) logic input for the receiving end Each input end of the output unit, when the microprocessor receives the optical demodulation signal corresponding to one of the N optical demodulation signals from the N demodulators via the input terminal, The microprocessor outputs the corresponding optical demodulation signal to the output end of the receiving logic input/output unit of the input terminal according to the decrypted pairing combination to obtain a corresponding image bit data; and J) The image restoration unit restores the image bit data to generate the source image data. The wireless optical communication method of claim 2, wherein the predetermined wireless optical communication architecture is a wavelength division multiplexing technology. The wireless optical communication method of claim 3, wherein M=N, and each carrier group has one light source carrier, and wavelengths of the light source carriers of the carrier groups are different from each other. The wireless optical communication method according to claim 3, wherein in the step (D), each of the modulators is modulated by an amplitude keying technique. The wireless optical communication method of claim 2, wherein the predetermined wireless optical communication architecture is an optical code division multiple access technology. The wireless optical communication method of claim 6, wherein each carrier group has a plurality of light source carriers, and wavelengths of all the light source carriers in the carrier groups are different from each other. The wireless optical communication method according to claim 7, wherein in the step (E), the optical multiplexing unit performs orthogonal processing on the optical modulation signals to complete multiplexing processing, in the step (G). The photo-demultiplexing unit performs orthogonal decoding on the optical multiplexing output signals to perform demultiplexing processing. The wireless optical communication method according to claim 6, wherein in the step (D), each of the modulators is modulated by an amplitude keying technique.