CN116389651A - Image safe transmission method based on ACO-OFDM visible light communication - Google Patents
Image safe transmission method based on ACO-OFDM visible light communication Download PDFInfo
- Publication number
- CN116389651A CN116389651A CN202310453091.3A CN202310453091A CN116389651A CN 116389651 A CN116389651 A CN 116389651A CN 202310453091 A CN202310453091 A CN 202310453091A CN 116389651 A CN116389651 A CN 116389651A
- Authority
- CN
- China
- Prior art keywords
- aco
- encrypted
- image
- ofdm
- chaotic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000004891 communication Methods 0.000 title claims abstract description 26
- 230000005540 biological transmission Effects 0.000 title claims abstract description 21
- 230000000739 chaotic effect Effects 0.000 claims abstract description 51
- 238000006243 chemical reaction Methods 0.000 claims abstract description 27
- 238000005516 engineering process Methods 0.000 claims abstract description 13
- 239000011159 matrix material Substances 0.000 claims description 11
- 239000013256 coordination polymer Substances 0.000 claims description 8
- 125000004122 cyclic group Chemical group 0.000 claims description 8
- 230000003287 optical effect Effects 0.000 claims description 7
- 238000013507 mapping Methods 0.000 claims description 4
- 238000007781 pre-processing Methods 0.000 claims description 4
- 102100029469 WD repeat and HMG-box DNA-binding protein 1 Human genes 0.000 claims 1
- 101710097421 WD repeat and HMG-box DNA-binding protein 1 Proteins 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 5
- 238000001228 spectrum Methods 0.000 description 3
- 238000005562 fading Methods 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- 206010011971 Decreased interest Diseases 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 230000021615 conjugation Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003203 everyday effect Effects 0.000 description 1
- 238000005286 illumination Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- 230000017105 transposition Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/32—Circuits or arrangements for control or supervision between transmitter and receiver or between image input and image output device, e.g. between a still-image camera and its memory or between a still-image camera and a printer device
- H04N1/32101—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title
- H04N1/32144—Display, printing, storage or transmission of additional information, e.g. ID code, date and time or title embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
- H04N1/32149—Methods relating to embedding, encoding, decoding, detection or retrieval operations
- H04N1/32267—Methods relating to embedding, encoding, decoding, detection or retrieval operations combined with processing of the image
- H04N1/32272—Encryption or ciphering
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
- H04B10/114—Indoor or close-range type systems
- H04B10/116—Visible light communication
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/001—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols using chaotic signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/44—Secrecy systems
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Computer Networks & Wireless Communication (AREA)
- Computer Security & Cryptography (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Optical Communication System (AREA)
Abstract
The invention discloses an ACO-OFDM visible light communication-based image safety transmission method, which is characterized by comprising the following steps of: the encryption is combined with the physical layer at the upper layer of the ACO-OFDM system. The specific process is as follows: encrypting an original image on the upper layer of the ACO-OFDM system based on a Fresnel diffraction double random phase encryption technology, and performing code conversion to obtain a calculation hologram; and then, mixing the SHA-256 values of the original image with an external key to determine initial values of two-dimensional hyperchaotic systems, generating four chaotic sequences, carrying out bit exclusive OR on odd bits and even bits of the transmitted binary bit stream by using the two sequences, carrying out chaotic scrambling on real parts and imaginary parts of the QAM symbol stream by using the other two sequences, and realizing encryption of a physical layer. The invention adopts the upper layer and physical layer of ACO-OFDM system to encrypt, further enhances the security of image transmission. In addition, the upper layer encrypts and converts the original image into a binary real-value calculation hologram, so that the anti-noise performance of the ACO-OFDM system is improved. The invention is suitable for the safe transmission of the image data between the visible light receiving and transmitting devices.
Description
Technical Field
The invention relates to the field of visible light communication and image transmission, in particular to an ACO-OFDM visible light communication-based image security transmission method.
Background
Information transmission in wireless networks is currently accomplished through techniques operating in the radio frequency band, such as: wi-Fi, bluetooth, NFC, cellular networks, satellite networks, and so on, each of which has its own performance characteristics and is used in accordance with the type of application. However, with the rise of the internet of things (Internet ofThings, ioT) and industry 4.0, the number of applications and devices connected to the network is increasing every day, and thus the demands on wireless access, capacity and security are exponentially increasing, and a great amount of information requires new technologies to support broadband services and accommodate existing traffic.
In order to solve the above problems and serious congestion of radio spectrum, researchers have developed a new technology called visible light communication (Visible Light Communication, VLC), which uses the visible light band for data transmission, and has the advantages of abundant spectrum resources, no electromagnetic pollution, high security, etc. In addition, visible light communication is a technology that uses the most widely used LED as an emission source at present, and has both illumination and communication, which makes it considered as a future communication with great potential.
To guarantee high data rate transmission and reduce implementation complexity, VLC may leverage orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) multi-carrier modulation schemes for radio frequencies. The OFDM is characterized in that the frequency selective fading of a communication channel is converted into a flat fading channel by using a one-dimensional frequency domain equalization technology with high efficiency and simplicity in calculation. Furthermore, OFDM ensures high data rate communication while enabling efficient use of spectrum resources. The OFDM multicarrier modulation format modulates amplitude and phase information of a carrier signal in the case of radio frequency based wireless communication. The visible light communication link is implemented with LEDs, and the fact that the LEDs produce incoherent light allows the OFDM time domain signal to modulate the intensity of the light source without being noticeable to the human eye. Therefore, VLC typically employs a special modem format of intensity modulation/direct detection (IM/DD), which forces the OFDM time domain signal to be both real-valued and unipolar in nature (i.e., positive). Therefore, in order to obtain the real-valued signal, hermitian symmetry constraint is performed on the input frame structure of the IFFT module, so that the real-valued property of the time-domain signal output by the IFFT is ensured. In order to generate a positive signal, various optical OFDM techniques have been proposed, such as direct offset optical OFDM (DCO-OFDM), asymmetric limited optical OFDM (ACO-OFDM), flip OFDM (Flip-OFDM), etc. Each variant of OFDM has a trade-off in terms of spectral efficiency, power efficiency, computational complexity, and bit error rate performance. ACO-OFDM based VLC is a potential candidate solution for VLC application, and the VLC system based on ACO-OFDM is provided without losing generality.
With the advent of the large data age, images play an increasingly important role in data transmission. However, in the image transmission process, it is also important to ensure the safety of the image. In the image transmission process, if no good security measures are available, a hacker or a malicious attacker can easily acquire important information in the image, thereby causing data leakage. This not only results in a loss of interest to the business or individual, but also affects the business's or individual's image and reputation in the marketplace.
In summary, it is necessary to protect the image transmission based on the ACO-OFDM visible light communication system, so as to ensure the information security.
Disclosure of Invention
The invention aims to provide an ACO-OFDM visible light communication-based image security transmission method.
The invention relates to an ACO-OFDM visible light communication-based image safety transmission method, which comprises the following steps:
and the transmitting end:
encrypting an original image based on a double random phase encryption technology of a Fresnel diffraction system, and performing code conversion to obtain a binary real value calculation hologram;
step (2) mixing SHA-256 values of an original image with an external key to determine initial values of two-dimensional hyperchaotic systems, and generating four chaotic sequences for encrypting binary bit streams and QAM symbol streams;
converting binary real value calculation holograms into binary bit streams in parallel and serial, and performing bit exclusive OR on odd bits and even bits of the binary bit streams respectively by using two of four chaotic sequences to obtain encrypted binary bit streams;
performing m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream, and performing chaotic scrambling on the real part and the imaginary part of the QAM symbol stream respectively by using the other two of the four chaotic sequences to obtain the encrypted QAM symbol stream;
step (5) serial-parallel conversion and hermitian mapping are carried out on the encrypted QAM symbol stream, an ACO-OFDM signal matrix is formed according to the ACO-OFDM data characteristic requirement, inverse Fast Fourier Transform (IFFT) is carried out on the ACO-OFDM signal matrix, and a real-valued time domain ACO-OFDM signal is generated;
sequentially adding a cyclic prefix CP, parallel-to-serial converting, clipping and negating wave treatment to the time domain ACO-OFDM signal, loading the time domain ACO-OFDM signal onto an LED through digital-to-analog conversion, transmitting the time domain ACO-OFDM signal through visible light, and transmitting the transmitted visible light signal to a receiving end through a spatial channel;
the receiving end:
the photoelectric detector PD at the receiving end converts the received optical signal into an electric signal, and then sequentially performs analog-digital conversion, serial-parallel conversion and cyclic prefix CP removal to obtain a received time domain ACO-OFDM signal;
step (2) carrying out fast Fourier transform FFT, inverse hermitian symmetric transform and parallel-serial conversion on the received time domain ACO-OFDM signal in sequence to obtain an encrypted QAM symbol stream;
step (3) adopting the same chaotic sequence key of the transmitting end to decrypt the received encrypted QAM symbol stream;
demodulating the decrypted QAM symbol stream to obtain an encrypted binary bit stream, decrypting by adopting a chaotic sequence key which is the same as that of a transmitting end, and then converting the encrypted binary real value into a binary real value calculation hologram in a serial-parallel manner;
and (5) decrypting the encrypted binary real value calculation hologram based on the double random phase decryption technology of the Fresnel diffraction system to obtain an original image.
Compared with the prior art, the invention has the following advantages:
the invention provides an image security transmission method based on the joint encryption of an upper layer and a physical layer of an ACO-OFDM visible light communication system, which realizes the multi-stage encryption of an image level, a bit level and a symbol level and improves the security of image information transmission.
The invention encrypts the original image by utilizing the Fresnel diffraction double random phase encryption technology, and codes and converts the original image into the binary real value calculation hologram, thereby improving the noise resistance of the system.
Among various chaotic systems, the two-dimensional hyper-chaotic system has the advantages of high iteration speed, strong robustness and the like. According to the invention, the binary bit stream and the QAM symbol stream are chaotic scrambled by using the chaotic sequences generated by the two-dimensional hyperchaotic systems, and the sensitivity of a chaotic key to an initial value is utilized, so that the cracking difficulty of the key is increased.
Drawings
FIG. 1 is a block diagram of a system architecture of the present invention;
FIG. 2 is a schematic diagram of image encryption based on Fresnel diffraction dual random phase encryption and holographic encoding;
fig. 3 is a schematic diagram of image decryption based on fresnel diffraction double random phase encryption and holographic encoding.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear and obvious, the invention is further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are to be considered in an illustrative sense only and are not intended to limit the invention.
As shown in fig. 1, the image security transmission method based on ACO-OFDM visible light communication of the present invention includes the following steps:
and the transmitting end:
encrypting an original image based on a double random phase encryption technology of a Fresnel diffraction system, and performing code conversion to obtain a binary real value calculation hologram;
step (2) mixing SHA-256 values of an original image with an external key to determine initial values of two-dimensional hyperchaotic systems, and generating four chaotic sequences for encrypting binary bit streams and QAM symbol streams;
converting binary real value calculation holograms into binary bit streams in parallel and serial, and performing bit exclusive OR on odd bits and even bits of the binary bit streams respectively by using two of four chaotic sequences to obtain encrypted binary bit streams;
performing m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream, and performing chaotic scrambling on the real part and the imaginary part of the QAM symbol stream respectively by using the other two of the four chaotic sequences to obtain the encrypted QAM symbol stream;
step (5) serial-parallel conversion and hermitian mapping are carried out on the encrypted QAM symbol stream, an ACO-OFDM signal matrix is formed according to the ACO-OFDM data characteristic requirement, inverse Fast Fourier Transform (IFFT) is carried out on the ACO-OFDM signal matrix, and a real-valued time domain ACO-OFDM signal is generated;
sequentially adding a cyclic prefix CP, parallel-to-serial converting, clipping and negating wave treatment to the time domain ACO-OFDM signal, loading the time domain ACO-OFDM signal onto an LED through digital-to-analog conversion, transmitting the time domain ACO-OFDM signal through visible light, and transmitting the transmitted visible light signal to a receiving end through a spatial channel;
the receiving end:
the photoelectric detector PD at the receiving end converts the received optical signal into an electric signal, and then sequentially performs analog-digital conversion, serial-parallel conversion and cyclic prefix CP removal to obtain a received time domain ACO-OFDM signal;
step (2) carrying out fast Fourier transform FFT, inverse hermitian symmetric transform and parallel-serial conversion on the received time domain ACO-OFDM signal in sequence to obtain an encrypted QAM symbol stream;
step (3) adopting the same chaotic sequence key of the transmitting end to decrypt the received encrypted QAM symbol stream;
demodulating the decrypted QAM symbol stream to obtain an encrypted binary bit stream, decrypting by adopting a chaotic sequence key which is the same as that of a transmitting end, and then converting the encrypted binary real value into a binary real value calculation hologram in a serial-parallel manner;
and (5) decrypting the encrypted binary real value calculation hologram based on the double random phase decryption technology of the Fresnel diffraction system to obtain an original image.
In the method, the transmitting end step (1) encrypts the original image based on the double random phase encryption technology of the fresnel diffraction system, and encodes and converts the original image into a binary real value calculation hologram, and the schematic diagram is shown in fig. 2, and specifically includes the following steps:
(1.1) encrypting the original image, placing the original image I (x, y) on the object plane Sigma, and placing a white noise random phase plate p on the object plane Sigma and close to the original image 1 (x, y) =exp (j2pi α (x, y)), at spectral plane Σ 1 On which is placed a second white noise random phase plate p 2 (x, y) =exp (j 2 pi beta (ζ, eta)), where α, beta e [0,1 ]]；z 1 And z 2 The distances of two Fresnel diffractions are respectively; assuming that the planar lightwave with wavelength lambda perpendicularly irradiates the object plane sigma, the original image passes through a first random phase plate p 1 Is z 1 After Fresnel diffraction reaching the second random phase plate p 2 The method comprises the steps of carrying out a first treatment on the surface of the Under fresnel approximation conditions, the complex amplitude distribution at the second random phase plate is:
q(ξ,η)＝F F {I(x,y)exp[j2πα(x,y)]；z 1 }
wherein F is F Representing fresnel transformations and then passing through the distance z 2 Fresnel diffraction of (c) reaches the output plane Σ 2 The complex amplitude distribution of the resulting encrypted image is:
E(x,y)＝F F {q(ξ,η)exp[j2πβ(ξ,η)]；z 2 }
(1.2) recording the encrypted image by the roman coding method, and converting the encrypted image E (x, y) into a binary real-valued calculation hologram E (m, n).
The method comprises the steps of (2) at a transmitting end, mixing SHA-256 values of an original image with an external key to determine initial values of two-dimensional hyperchaotic systems, and generating four chaotic sequences for encrypting binary bit streams and QAM symbol streams;
one of the chaotic models adopted by the invention is a cross two-dimensional hyper-chaotic system (Cross two dimensional hyperchaotic system, CTDHCS) model, and the iteration formula is as follows:
where α, β are two control parameters of CTDHCS, which exhibits hyperchaotic properties when α=2 and β=1;
another chaotic model is a Gao's two dimensional hyperchaotic system, GTDHCS model, whose iterative formula is as follows:
where μ, γ is two control parameters of GTDHCS, which exhibits hyperchaotic properties when μ=5 and γ=5;
the specific steps for generating four chaotic sequences are as follows:
(2.1) inputting the original image into an SHA-256 function to generate a hash value H, namely a hexadecimal sequence with the length of 64;
(2.2) mixing the hash value H with an external key EK (which consists of 64 truly random hexadecimal numbers) using sk=bitxor (H, EK), where bitxor (a, b) represents a bitwise exclusive-or operation of a and b, to obtain the session key SK, further improving confidentiality;
(2.3) extracting an initial value of the chaotic system from the session key SK, expressed as follows:
wherein, the hex2dec operation can convert the character string of hexadecimal number into decimal integer, A (1) and B (1) are initial values of extracted CTDHCS, U (1) and V (1) are initial values of extracted GTDHCS;
(2.4) iterating the extracted initial values according to the two-dimensional hyper-chaotic systems to obtain four chaotic sequences A, B, U and V; firstly, iterating an initial value (n+l) times by using two-dimensional hyper-chaotic system iteration formulas, thereby generating 4 sequences with the length of (n+l): a (i), B (i), U (i), V (i), i=1, 2, …, n+l, where l is a pre-iteration time to eliminate negative effects caused by transient processes of the chaotic system; the chaotic sequences a and B are then applied to encryption of the binary bit stream and the chaotic sequences U and V are applied to encryption of the QAM symbol stream.
The method, the transmitting end step (3), converts binary real value calculation hologram parallel-serial into binary bit stream, applies two of four chaos sequences to respectively carry out bit exclusive OR on odd bit and even bit of the binary bit stream to obtain encrypted binary bit stream, and specifically comprises the following steps:
(3.1) binary real-valued computed holograms are converted into binary bit streams in parallel-serial;
(3.2) preprocessing the chaotic sequences A and B as follows:
wherein the floor function returns a maximum integer not greater than a given value, the abs function returns an absolute value of the given value, mod (a, b) returns a remainder of a divided by b, and the processed chaotic sequence only contains 0 and 1, namely a (i), b (i) epsilon {0,1};
(3.3) performing bit exclusive OR on the chaos sequences a (i) and b (i) obtained after pretreatment and the odd bit and the even bit of the binary bit stream x after parallel-serial conversion respectively to obtain an encrypted binary bit stream
The expression is as follows:
where bitxor (a, b) represents a bitwise exclusive or operation of a and b.
The method, the transmitting end step (4), carries out m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream, and carries out chaotic scrambling on the real part and the imaginary part of the QAM symbol stream by using the other two of four chaotic sequences to obtain the encrypted QAM symbol stream, which comprises the following steps:
(4.1) performing m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream;
(4.2) preprocessing the chaotic sequences U and V as follows:
wherein the floor function returns a maximum integer not greater than a given value, the abs function returns an absolute value of the given value, mod (a, b) returns a remainder of a divided by b, and the processed chaotic sequence only comprises-1 and 1, namely u (i), v (i) epsilon-1, 1;
(4.3) QAM symbol stream is composed of s= [ S ] 1 ,S 2 ,...,S l ] T Representation of [ wherein ]] T Referring to matrix transposition, l refers to the length of the QAM symbol stream; multiplying the preprocessed chaos sequences u (i) and v (i) with the real part and the imaginary part of the QAM symbol stream S respectively, and encrypting QAM symbol stream
Expressed as:
where real (a) returns the real part of a and imag (a) returns the imaginary part of a.
The method comprises the steps (5) and (6) at the transmitting end and the steps (1) and (2) at the receiving end, so that ACO-OFDM signals are generated, transmitted and received;
transmitting end step (5) encrypts the QAM symbol stream
Serial-parallel conversion is carried out to obtain an effective data matrix of ACO-OFDM signals, which is expressed as follows:
wherein Q and M are the number of OFDM effective data subcarriers and the total number of OFDM symbols, respectively, the invention is based on an ACO-OFDM visible light communication system, only odd subcarriers are modulated and allocated hermitian symmetry, and even subcarriers are allocated to zero, so Q is one fourth of the number N of OFDM subcarriers, i.e., q=n/4; performing hermitian mapping on effective data matrix of ACO-OFDM signal, modulating odd sub-carrier and distributing hermitian symmetry, and setting even sub-carrier to zero to form ACO-OFDM signal matrix according to ACO-OFDM data characteristic requirement
Expressed as:
for ACO-OFDM signal matrix
Performing Inverse Fast Fourier Transform (IFFT) to generate real-valued time domain ACO-OFDM signals;
a transmitting end step (6) sequentially adds a cyclic prefix CP, performs parallel-to-serial conversion, cuts out amplitude limiting and cutting negative wave treatment on a time domain ACO-OFDM signal, loads the signal onto an LED through digital-to-analog conversion, transmits the signal through visible light, and transmits the transmitted visible light signal to a receiving end through a space channel;
the receiving end step (1) is that the receiving end photoelectric detector PD converts the received optical signal into an electric signal, and then analog-digital conversion, serial-parallel conversion and cyclic prefix CP removal are sequentially carried out, so that a received time domain ACO-OFDM signal is obtained;
the receiving end step (2) sequentially carries out fast Fourier transform FFT, inverse Hermite symmetric transform and parallel-serial conversion on the received time domain ACO-OFDM signal to obtain an encrypted QAM symbol stream;
the decryption method corresponding to the receiving end specifically comprises the following steps:
the receiving end step (3) corresponds to the decryption of the encrypted QAM symbol stream in the transmitting end step (4), and the same chaotic sequence key in the transmitting end step (4) is adopted to decrypt the received encrypted QAM symbol stream;
the step (4) of the receiving end corresponds to the step (3) of decrypting the encrypted binary bit stream of the transmitting end, and the same chaotic sequence key of the step (3) of the transmitting end is adopted to decrypt the received encrypted binary bit stream;
the receiving end step (5) corresponds to the decryption of the encrypted image in the transmitting end step (1), the image decryption schematic diagram is shown in fig. 3, in the decryption process, the received binary real value calculation hologram E '(m, n) is placed on an input plane, monochromatic light is vertically incident, then standard Fourier transform is carried out, and the calculation hologram is reproduced to obtain an encrypted image E' (x, y) and conjugate thereof; taking conjugate of the encrypted image E' (x, y) to realize decryption, introducing the-1-level reproduction conjugate image into a Fresnel diffraction double-random-phase decryption system, and respectively carrying out twice distance z 3 And z 4 Fresnel diffraction of (c) and two random phase plates p 3 And p 4 Modulation of (2)Decryption, obtaining a decrypted original image I '(x, y) at an output plane Σ':
I'(x,y)exp[-j2πα(ξ,η)]＝F F {F F [E'*(x,y)；z 3 ]exp[j2πβ(ξ,η)]；z 4 }
wherein is represents conjugation, z 3 ＝z 2 ,z 4 ＝z 1 ，p 3 ＝p 2 ,p 4 ＝p 1 。
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (6)
1. An ACO-OFDM visible light communication-based image security transmission method is characterized by comprising the following steps:
and the transmitting end:
encrypting an original image based on a double random phase encryption technology of a Fresnel diffraction system, and performing code conversion to obtain a binary real value calculation hologram;
step (2) mixing SHA-256 values of an original image with an external key to determine initial values of two-dimensional hyperchaotic systems, and generating four chaotic sequences for encrypting binary bit streams and QAM symbol streams;
converting binary real value calculation holograms into binary bit streams in parallel and serial, and performing bit exclusive OR on odd bits and even bits of the binary bit streams respectively by using two of four chaotic sequences to obtain encrypted binary bit streams;
performing m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream, and performing chaotic scrambling on the real part and the imaginary part of the QAM symbol stream respectively by using the other two of the four chaotic sequences to obtain the encrypted QAM symbol stream;
step (5) serial-parallel conversion and hermitian mapping are carried out on the encrypted QAM symbol stream, an ACO-OFDM signal matrix is formed according to the ACO-OFDM data characteristic requirement, inverse Fast Fourier Transform (IFFT) is carried out on the ACO-OFDM signal matrix, and a real-valued time domain ACO-OFDM signal is generated;
sequentially adding a cyclic prefix CP, parallel-to-serial converting, clipping and negating wave treatment to the time domain ACO-OFDM signal, loading the time domain ACO-OFDM signal onto an LED through digital-to-analog conversion, transmitting the time domain ACO-OFDM signal through visible light, and transmitting the transmitted visible light signal to a receiving end through a spatial channel;
the receiving end:
the photoelectric detector PD at the receiving end converts the received optical signal into an electric signal, and then sequentially performs analog-digital conversion, serial-parallel conversion and cyclic prefix CP removal to obtain a received time domain ACO-OFDM signal;
step (2) carrying out fast Fourier transform FFT, inverse hermitian symmetric transform and parallel-serial conversion on the received time domain ACO-OFDM signal in sequence to obtain an encrypted QAM symbol stream;
step (3) adopting the same chaotic sequence key of the transmitting end to decrypt the received encrypted QAM symbol stream;
demodulating the decrypted QAM symbol stream to obtain an encrypted binary bit stream, decrypting by adopting a chaotic sequence key which is the same as that of a transmitting end, and then converting the encrypted binary real value into a binary real value calculation hologram in a serial-parallel manner;
and (5) decrypting the encrypted binary real value calculation hologram based on the double random phase decryption technology of the Fresnel diffraction system to obtain an original image.
2. The method for safely transmitting an image based on ACO-OFDM visible light communication according to claim 1, wherein the transmitting-side step (1) specifically comprises:
the method comprises the steps of (1.1) encrypting an original image, obtaining an encrypted image after the original image is modulated and encrypted by two Fresnel diffractions and two random phase plates, and performing standard Fourier transform on the encrypted image;
(1.2) recording the encrypted image by using a Roman coding mode, and converting the encrypted image into a binary real-valued calculation hologram.
3. The method for safely transmitting an image based on ACO-OFDM visible light communication according to claim 1, wherein the transmitting-side step (2) specifically comprises:
(2.1) inputting the original image into an SHA-256 function to generate a hash value H, namely a hexadecimal sequence with the length of 64;
(2.2) mixing the hash value H with an external key EK (which consists of 64 truly random hexadecimal numbers) using sk=bitxor (H, EK), where bitxor (a, b) represents a bitwise exclusive-or operation of a and b, to obtain the session key SK, further improving confidentiality;
(2.3) extracting an initial value of the chaotic system from the session key SK;
and (2.4) iterating according to the extracted initial values according to the two-dimensional hyper-chaotic systems to obtain four chaotic sequences.
4. The method for safely transmitting an image based on ACO-OFDM visible light communication according to claim 1, wherein the transmitting-side step (3) specifically comprises:
(3.1) binary real-valued computed holograms are converted into binary bit streams in parallel-serial;
(3.2) preprocessing two of the four chaotic sequences, wherein the processed chaotic sequences only comprise 0 and 1;
and (3.3) respectively carrying out bit exclusive OR on the preprocessed chaotic sequence and the odd-numbered bits and the even-numbered bits of the binary bit stream subjected to parallel-serial conversion to obtain an encrypted binary bit stream.
5. The method for safely transmitting an image based on ACO-OFDM visible light communication according to claim 1, wherein the transmitting-side step (4) specifically comprises:
(4.1) performing m-QAM quadrature amplitude modulation on the encrypted binary bit stream to obtain a QAM symbol stream;
(4.2) preprocessing the other two of the four chaotic sequences, wherein the processed chaotic sequences only comprise-1 and-1;
and (4.3) multiplying the preprocessed chaotic sequence by the real part and the imaginary part of the QAM symbol stream respectively.
6. The image security transmission method based on ACO-OFDM visible light communication according to claims 1 to 5, wherein the decryption method corresponding to the receiving end specifically comprises:
the receiving end step (3) corresponds to the decryption of the encrypted QAM symbol stream in the transmitting end step (4), and the same chaotic sequence key in the transmitting end step (4) is adopted to decrypt the received encrypted QAM symbol stream;
the step (4) of the receiving end corresponds to the step (3) of decrypting the encrypted binary bit stream of the transmitting end, and the same chaotic sequence key of the step (3) of the transmitting end is adopted to decrypt the received encrypted binary bit stream;
the receiving end step (5) corresponds to the decryption of the encrypted image in the transmitting end step (1), the received binary real value calculation hologram is subjected to primary standard Fourier transform to obtain the encrypted image and conjugate thereof, and the-1-level reproduction conjugate image is subjected to two Fresnel diffraction and modulation decryption of two random phase plates to recover the original image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310453091.3A CN116389651A (en) | 2023-04-25 | 2023-04-25 | Image safe transmission method based on ACO-OFDM visible light communication |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310453091.3A CN116389651A (en) | 2023-04-25 | 2023-04-25 | Image safe transmission method based on ACO-OFDM visible light communication |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116389651A true CN116389651A (en) | 2023-07-04 |
Family
ID=86969354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310453091.3A Pending CN116389651A (en) | 2023-04-25 | 2023-04-25 | Image safe transmission method based on ACO-OFDM visible light communication |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116389651A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117375876A (en) * | 2023-08-24 | 2024-01-09 | 南京信息工程大学 | High-safety communication method based on dynamic aliasing of time domain spectrum on digital domain |
-
2023
- 2023-04-25 CN CN202310453091.3A patent/CN116389651A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117375876A (en) * | 2023-08-24 | 2024-01-09 | 南京信息工程大学 | High-safety communication method based on dynamic aliasing of time domain spectrum on digital domain |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111525998B (en) | High-reliability optical transmission method based on mode, time slot and frequency composite vector | |
| CN111934848B (en) | Intelligent optimized four-dimensional chaotic vector encryption orthogonal transmission method | |
| CN112019321B (en) | Five-dimensional optical probability shaping encryption method based on high-dimensional chaotic system | |
| CN112165378B (en) | Low-PAPR high-safety optical access method with high resource utilization rate | |
| CN105577360B (en) | A kind of OOFDM encryption systems based on chaos sequence mapping | |
| CN111342957B (en) | Method and device for distributing CO-OFDM (CO-orthogonal frequency division multiplexing) key based on Y-00 protocol | |
| Padmapriya et al. | ECC joins first time with SC-FDMA for Mission “security” | |
| Zhou et al. | Physical layer dynamic key encryption in OFDM-PON system based on cellular neural network | |
| Li et al. | Secure key distribution strategy in OFDM-PON by utilizing the redundancy of training symbol and digital chaos technique | |
| CN111786771B (en) | Polarization, phase and mode dynamic disturbance method | |
| CN116389651A (en) | Image safe transmission method based on ACO-OFDM visible light communication | |
| Wang et al. | Physical layer encryption in DMT based on digital multi-scroll chaotic system | |
| Wu et al. | Joint security enhancement and PAPR mitigation for OFDM-NOMA VLC systems | |
| Liu et al. | A novel chaos-based physical layer security transmission scheme for Internet of Things | |
| CN117749278A (en) | NOMA transmission system based on constellation diagram transformation and chaos enhancement | |
| Ni et al. | PHY‐Aided Secure Communication via Weighted Fractional Fourier Transform | |
| Wang et al. | Data Center Secure Communication via DNA Hyperchaotic Encryption | |
| Wang et al. | Multi-Gbit/s real-time modems for chaotic optical OFDM data encryption and decryption | |
| Tran et al. | Performance evaluation of 802.11 ah physical layer phase encryption for IoT applications | |
| CN114257368B (en) | OFDM transmission method and device based on floating probability and bubble sequencing encryption | |
| Tang et al. | FBMC/OQAM security strategy based on diversity DNA encryption | |
| Wang et al. | Secure image transmission in orthogonal frequency division multiplexing visible light communication systems | |
| Ameen et al. | Hyperchaotic based encrypted audio transmission via massive MIMO-GFDM system using DNA coding in the antenna index of PSM | |
| Xu et al. | Diffusion-assisted quantum noise stream cipher for physical layer security in UFMC | |
| Yang et al. | Physical layer signal encryption using digital chaos in OFDM-PON |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |