107 results about "Optical encryption" patented technology

The present invention relates generally to an integrated optics encryption device. The preferred embodiment of the invention is an integrated optics encryption device comprising a coherent light source connected to a multi-functional integrated optics chip (MIOC). The MIOC comprises two divergent paths with mirrored ends. The MIOC also has an encrypted message output. One path is connected to a message signal input that can alter the refractive index of the path. The other path is connected to a key signal input that can alter the refractive index of the other path.

The invention discloses a method for improving an optical scanning holographic tomography effect, and belongs to the field of optical tomography. The method can solve the defect in the conventional optical scanning technology that restored section images have louder out-of-focus noise, in real time. The method comprises the following steps: utilizing a random phase in the optics encryption technique, changing a certain pupil function in a conventional optical scanning holographic system into a stochastic phase pupil function, and equaling restore of out-of-focus layer images into decryption under the condition of mistakenly decrypting a secret key, thereby enabling the out-of-focus layer images overlaid on the restored section images to be gaussian white noise with statistical independence and greatly reducing the influence of the out-of-focus noise on the focus layer images. Meanwhile the out-of-focus noise can also be filtered through design of a gaussian filter, so that the longitudinal resolution of the system can be improved; besides, through the adoption of the method, the bandwidth of the optical transfer function is wider, and the transverse resolution of the restored section images can be higher.

The invention relates to securing of information utilising optical imaging technologies and more specifically to phase encryption and decryption of images. An image is encrypted into a mask having a plurality of mask resolution elements (X_m, Y_m) by encoding the image using e.g. a phase mask with an encoded phase value φ (X_m, Y_m) and an encoded amplitude value a (X_m, Y_m), and by further encrypting the mask (using e.g. a spatial light modulator) by addition of an encrypting phase value φ_c (X_m, Y_m) to the encoded phase value φ (X_m, Y_m) and by multiplication of an encrypting amplitude value a_c (X_m, Y_m) with the encoded phase value a (X_m, Y_m). The method of decrypting comprises the steps of decrypting the mask by radiating electromagnetic radiation towards the mask and inserting into the path of the electromagnetic radiation a complex spatial electromagnetic radiation modulator comprising modulator resolution elements, the decrypting phase value φ_d (X_d, Y_d) and the decrypting amplitude value a_d (X_d, Y_d) respectively, of a modulator resolution element (X_d, Y_d) being substantially equal to −φ_c (X_m, Y_m) and a_c⁻¹ (X_m, Y_m).

The invention relates to a two-step quadrature phase-shift interferometry-based optical image encryption device and a method, which belong to the optical image processing technical field. The two-step quadrature phase-shift interferometry-based optical image encryption device comprises an optical image encryption device and an optical image decryption device. Due to the adoption of the two-step quadrature phase-shift interferometry-based optical image encryption device, strength information of substance light waves and reference light waves are not required to record, so the calculation amount and the storage amount can be reduced, the transmission efficiency of the information is improved, the system is simplified, and the cost is reduced. Since only two holographs are required to record, the experimental operation steps can be simplified by reducing the recording times. Since the charge coupled device (CCD) recorded digital hologram has advantages of real-time recording, digital memory, digital transmission and the like, encrypted information can be transmitted to an electronic computer of the decryption device to be decrypted in an electronic way to reappear, and the optical encryption technology can be better compatible with the digital signal processing and communication system so as to be widely used. In addition, system parameter key is also increased while the security of a double random phase coding method is guaranteed, so the security of the system is further improved.

Provided is an optical encryption method based on chaos and computer-generated holography. By means of the method, a chaos sequence is successfully used for forming a random phase array to carry out modulation coding on object light waves, the boqi coding method which revises off-axis reference light is used, and optical encryption and decryption are achieved on the basis of computer-generated holography. The invention belongs to the technical field of information security. In the decryption process, by means of the method, as long as correct chaos sequence initial values are obtained, the random phase array can be obtained, and therefore clear initial images can be rebuilt combining correct system architecture parameters. Compared with a conventional random phase encryption method, the chaos sequence initial values are used as secret keys, and therefore difficulty of phase array storage and transmission does not exist any longer, data bulk of the secret keys is greatly compressed, and meanwhile, digitization of computer-generated holography technology encryption information is more beneficial for storage and transmission of information.

A compressive sensing theory-based correlated imaging optical encryption method is provided. The compressive sensing theory-based correlated imaging optical encryption method includes the following steps of: (1) encryption: a random modulation signal is adopted as a key, and picture-text information to be encrypted is adopted as a plaintext, and correlation imaging is performed on the key and the plaintext so as to obtain a series of encrypted information, that is a ciphertext; (2) transmission: when information is transmitted, a transmitter and a receiver both share the key, and the ciphertext is transmitted between the transmitter and the receiver; and (3): decryption: compressive sensing calculation is performed on the key and the ciphertext in the decryption, and plaintext information is reconstructed. According to the compressive sensing theory-based correlated imaging optical encryption method of the invention, the key is distributed in a one-time pad manner, the randomness of the key enhances the randomness of the ciphertext, and therefore, the difficulty of deciphering is increased. A compressive sensing algorithm can reconstruct the plaintext under the situation of few sampling times, and therefore, calculation complexity of correlation calculation is decreased, and a new method is provided for correlated imaging optical encryption, and at the same time, more encrypted information can be transmitted under the same calculation times.

The invention discloses a virtual optical encryption method based on chaotic mapping and belongs to the field of information security technology and non-mathematical encryption and decryption technology. Random templates of key parameters are generated through spatial-temporal chaotic mapping, system security is enhanced and an information encryption method based on a virtual optical system is formed. Aiming at the most important problem in a virtual optical encryption system, namely, generation of the random templates, the method is based on the spatial-temporal chaotic mapping and the random templates with fine statistical performance are generated. Combining the random templates with other key parameters in the virtual optical encryption system, an encrypted ciphertext is obtained by calculating discrete Fresnel transform of a plaintext and the random templates and discretion of complex amplitude transmittance function of a lens. A decrypted plaintext is obtained by calculating reverse Fresnel transform.

The present invention relates to an apparatus and method for the encryption and decryption of optically transmitted data, and more particularly to the encryption and decryption of optical data transmitted and received using only optical components. Because only optical components are used, the encryption and decryption is independent of the data rate of the optical signal. The apparatus may include an encryption device that operates by receiving and combining both an unencrypted optical signal as well as a delayed optical signal that is based on the unencrypted optical signal. An optical delay may be configured in a number of different ways and may be used for delaying the unencrypted optical signal. The apparatus may further include a decryption device that receives and combines an encrypted optical signal as well as a delayed optical signal that is based on the encrypted optical signal. An optical delay may be configured in a number of different ways and may be used for delaying the encrypted optical signal. To properly work together, the apparatus and method require that the optical delay on the encryption side perfectly match the optical delay on the decryption side in both the length of delay and arrangement.

The invention relates to the technical field of information security, and discloses an optical image encryption method based on a quantum cell nerve network hyperchaotic system, for solving the defect of insufficient non-linear degree of a conventional optical encryption system. According to the invention, an optical image is encrypted and decrypted by use of the quantum cell nerve network hyperchaotic system, due to the hyperchaonic characteristic of a quantum cell nerve network, the linearity characteristic of a conventional double-random phase coding optical encryption technology is made up for, and the optical image encryption method has the security characteristics of large secret key space and high anti-attack capability. Besides, since a quantum dot and a quantum cell automatic machine are novel nanometer-level electronic devices which transmit information through coulomb interaction, compared to the prior art, the quantum cell automatic machine has the advantages of super-high integration, super-low power consumption, lead-free integration and the like.

The present invention relates to a double-image optical encryption method. The method comprises: two images P1(x, y) and P2(x, y) to be encrypted are respectively taken as an amplitude and a phase to combine a complex amplitude plaintext P(x, y) which clings to a random phase template M0(x, y) and is arranged at the input plane of an optical 4f system; a plane wave generated by a beam of the coherent light is employed to vertically irradiate the input plane of the system, three different random phase templates M1(u, v), M2(u, v) and M3(u, v) are respectively arranged at a frequency spectrum surface at three exposures for applying different frequency domain phase modulation, and the three corresponding intensity graphs I1(x, y), I2(x, y) and I3(x, y) are recorded on an output plane to be taken as the system cryptographs. The present invention further provides a decryption method corresponding to the double-image optical encryption method. The method comprises: providing the initial conjecture of the complex amplitude plaintext; and employing the corrected GS iteration phase retrieval algorithm to perform iteration processing with preset times of the initial conjecture to obtain the plaintext so as to extract two secret images. The double-image optical encryption method with high safety intensity and the decryption method thereof can greatly improve the safety of the encryption method.

A pure phase based optical encryption-decryption system comprises optical devices including optical devices such as a coherent light source. Light beams outputted by the coherent light source are split into two paths through a collimation system and a 3dB optical beam splitter; the light beam in one path passes through a first polarization rotator and a phase generator sequentially, and a phase generator control module connected with the phase generator applies a control program to the phase generator so as to complete pure-phase encryption of whole optical information; the light beam in the other path passes through a second polarization rotator, a phase recovery generator and a third polarization rotator; the light beam encrypted through the phase generator and the light beam transmitted by the third polarization rotator are combined on an optical beam combiner; the combined light beam enters a photoelectric detection module through a polarizer; the photoelectric detection module converts optical signals into electric signals which are sent to the phase recovery control module by means of servo, and the phase recovery control module realizes recovery of required wavefront information on the basis of certain evaluation functions and optimization algorithms. The pure phase based optical encryption-decryption system has the advantages of high safety, quickness and convenience in information encryption and decryption.

The invention discloses an optical encryption system and method based on random light field space coherent structure regulation and control. The system comprises a light source assembly and an encryption light path; the light source assembly comprises a laser and a linear polarizer, and a first convex lens, a random phase screen and a second convex lens are sequentially arranged in the encryption light path. The complete phase line polarized light passes through a to-be-encrypted object and then enters a first convex lens, the first convex lens projects an image of the to-be-encrypted object to a random phase screen, and the random phase screen converts the complete phase line polarized light containing the image of the to-be-encrypted object into non-phase line polarized light. And the second convex lens performs fractional order Fourier transform on the non-phase line polarized light and encrypts optical information contained in the non-phase line polarized light. The method is optical encryption based on random light field second-order statistical characteristic regulation and control, the security is high, ciphertext information is difficult to measure, the corresponding decryption method is novel, ciphertext measurement is not needed, the encrypted light robustness is good, and the turbulence influence can be overcome to a certain extent.

The invention discloses a method for hiding multiple images in a QR code based on compressed sensing and orthogonal modulation, and belongs to the field of optical image hiding and encryption. According to the method disclosed by the invention, a total measurement value expressed by decimal numerals of multiple images is obtained by using the compressed sensing and orthogonal modulation technologyand is stored in the form of the QR code; during decoding, the QR code is scanned by using a mobile phone or other photoelectric devices to obtain the total measurement value again, and then block reconstruction of the whole image or the partial reconstruction in the multiple images is achieved according to the needs. From an optical encryption point of view, the compressed sensing and orthogonalmodulation process of the invention can also be considered as two security levels, which must be completely correct at two levels to obtain the reconstructed images, and thus having good encryption performance.

The invention provides a binary channel multiple fingerprints optical encryption method comprising an encryption process and a deciphering process. A laser beam generator emits linearly polarized lights which are divided by a beam splitter into transmitting light and reflecting light. The transmitting light arrives to a left channel encryption key with fingerprint images and generates left channel modulated lasers. The reflecting light arrives to the right channel encryption key with fingerprint images and generates right channel modulated lasers. Recognizing the non-duplication characteristic of a biosignature, the invention integrates biological feature identification technologies with optical information processing technologies and provides such a binary channel multiple fingerprints optical encryption method, which is highly reliable and secure for encryption key management and is convenient for people to carry around. The method has a good application prospect in the information safety field.

The invention discloses image encryption and decryption methods and image encryption and decryption devices based on optical encryption and decryption technologies. The image encryption method comprises that an image to be encrypted is converted into a binary sequence code; according to a preset sequence conversion rule, the binary sequence code is converted into a decimal sequence code; according to the sequence from the head bit to the tail bit in the decimal sequence code, the decimal sequence code is divided into fragments, and the capacity of each fragment is set to be lower than or equivalent to the maximal capacity of a two-dimensional (2D) code; and the fragments are converted into 2D codes corresponding to the fragments, the 2D codes are encrypted optically, and the encrypted 2D codes are restored to the image to be encrypted via optical decryption. The 2D codes serves as carriers of the image, and are encrypted optically, the image restored via optical decryption is prevented from interference of spot noises, and the decrypted image is clearer and more complete.

The invention discloses a nonlinear metasurface based four-wave mixing holographic multiplexing method, and belongs to the micro nano holographic field. The method comprises that a metasurface is composed of an array with nanometer rectangular hole structures in different geometric sizes; the geometric sizes of the nanometer rectangular hole structures are changed, so that the nonlinear metasurface can randomly regulates the amplitude and phase of an output nonlinear frequency signal; complex amplitude distribution of the nonlinear light field output in different sizes can be obtained by fullwave vector calculation; an amplitude type hologram is calculated based on an optimized GS algorithm, and a bit coding method is used to code the hologram of the rectangular hole structure; rectangular hole structure distribution is determined by coding, and the corresponding nonlinear metasurface structure array is generated; and two beams of femtosecond pulses in different frequency are input torealize nonlinear holographic space and frequency multiplexing of the same nonlinear metasurface structure array. The method can be applied to the fields including signal processing, optical storage,high-dimensional holographic anti-counterfeiting and optical encryption.

The invention relates to a significance area protection method based on an encryption image with visual meaning. The method is characterized in that a significance area is extracted via low-level feature of an image; a proper encryption scheme, which is designed by utilizing a chaotic encryption technology and/or an optical encryption technology, is used to preprocess the extracted significance area; and a random natural image is selected as a reference image, and the pre-encrypted image is converted into the encryption image with visual meaning. Key data of the image can be protected effectively.

The present disclosure provides a fluid-optical encryption system and a method thereof. The fluid-optical encryption system uses a fluid surface that changes topology over time to modulate the wave front of an electromagnetic signal in an encryption, decryption, authentication or other communication system. The electromagnetic signal can be pulsed or continuous, coherent or non-coherent, and can be optical or in another wavelength range such as micrometer or infrared. The information carrying signal is either transmitted through the fluid system or reflected off the surface of the fluid system. The fluid system time dependent change can be induced by mechanical vibration in the fluid container, distorting the fluid container, acoustic waves through the fluid, or by surface tension changes at the boundary of the fluid cause by electrowetting or electrostatic effects. The fluid surface can exhibit patterns that oscillate or change periodically, or change in a chaotic manner.

A four-dimensional multiplexing method and four-dimensional multiplexing system are provided for optical networks. The method includes receiving sensor data to be transmitted on an optical network. The method also includes encoding the sensor data into an optical signal employing one or more multiplexing systems. The method additionally includes transmitting the optical signal over the optical network. The method further includes decoding the optical signal into the sensor data employing the one or more multiplexing systems. The method also includes controlling an operation of a processor-based machine responsive to the sensor data.

The invention puts forward a double-random-phase multi-image parallel encryption no-noise recovery method based on a QR (Quick Response) code, and belongs to the field of optical encryption. A traditional double-random-phase multi-image parallel encryption method is characterized in that a decryption effect is seriously affected since a decryption image has a serious crosstalk noise problem due tothe interaction superposition of multi-image information. Certain existing methods used for noise reduction only can inhibit the crosstalk noise to a certain degree but can not remove the crosstalk noise. The principle architecture of the method is the same with the principle architecture of a traditional double-random-phase multi-image parallel encryption system. The difference is that the QR code is taken as a data container, the anti-noise ability of the QR code can be used for effectively eliminating the problem of the crosstalk noise, and the system exhibits better robustness.

The invention relates to an optical encryption method based on correlated imaging. The method comprises the following steps: encryption: taking a plurality of random matrixes generated by a computer as a secret key 1, taking an image to be encrypted as a plaintext, and multiplying the secret key by the plaintext to generate a ciphertext; taking the ciphertext as a constraint, establishing a camouflage image and a plurality of corresponding modulation matrixes, and enabling the camouflage image and the to-be-encrypted image to have the same ciphertext; embedding the random matrix into the modulation matrix through a watermark embedding algorithm and an encryption algorithm of the image to generate a new matrix as a secret key; transmission: transmitting the secret key 2 and the ciphertext at the same time; and decryption: through a watermark extraction algorithm and a decryption algorithm of the image, extracting the secret key 1 from the secret key 2, carrying out association calculation with the ciphertext, reconstructing the encrypted image, and reconstructing a plaintext. According to the optical encryption method, safe information transmission is provided for a user, importantinformation leakage is avoided, the defect that in the prior art, the calculated amount is large is overcome, and the optical decryption process and difficulty of a receiver are simplified.

The invention provides an asymmetric optical image encryption method based on cylindrical diffraction transformation and equivalent mode decomposition. The method can effectively resist attacks of aniteration recovery method. According to the method, a classical asymmetric optical encryption technology based on equivalent mode decomposition is simply improved; cylindrical diffraction is used forreplacing Fresnel diffraction or Fraunhofer diffraction, and a pure amplitude ciphertext and a pure phase private key are used for replacing two complex amplitude masks, so that the security of the encryption method can be greatly improved, and particularly, the attack of an iterative recovery method can be resisted.

The invention relates to the technical field of image processing, and discloses a color image optical encryption method, which can be regarded as two encryption operations as a whole: in the first encryption operation, RGB channel components of a color image are converted into a real-value computer-generated hologram by using Fresnel diffraction to realize hiding of pixel information of a plaintext image; and information crosstalk between RGB channel components is overcome by comprehensively setting diffraction distance and reference light direction parameters to adjust the position of a reproductive image of each channel component, so that the color component of each channel can be accurately recovered in the decryption process; in the second encryption operation, the pixels of the computer-generated hologram are replaced and diffused by using a transformed Logistic chaotic system to obtain a meaningless white noise image as a final ciphertext image; the encryption operation enhances the sensitivity of the ciphertext to the plaintext change by means of the chaotic system characteristics and the diffusion mechanism, enhances the ability of the ciphertext to resist statistical attack and ciphertext-only attack, and further improves the system security.

The present invention relates to a method and apparatus for obtaining the equivalent key of the random phase coding-based optical encryption system. The apparatus includes a point light source structure, an optical 4f structure, a pure phase space light modulator and a feedback control device. According to the apparatus, the phase modulation parameter of the pure phase space light modulator is adjusted, so that the light intensity of the center of an output surface image can be maximum, and the phase modulation parameter is adopted as the equivalent key of the optical encryption system. According to the method, modulation is completed through the apparatus. With the method and apparatus adopted, the equivalent key of the optical encryption system parameter can be obtained simply, and cost is low.

The invention provides a chiral optical element, a chiral optical encryption assembly and a chiral element design method, and relates to the technical field of optical chiral construction and opticalencryption. The chiral optical element provided by the invention comprises a substrate and a metal microstructure connected to the substrate; the metal microstructure comprises a first arc-shaped part, a second arc-shaped part and an extension part, and a central angle corresponding to the first arc-shaped part and a central angle corresponding to the second arc-shaped part are opposite vertex angles; the extending part is connected between the first arc-shaped part and the second arc-shaped part and extends along the side line of any central angle of the first arc-shaped part and the second arc-shaped part. The optical response of the chiral optical element provided by the invention has a remarkable optical spin selection characteristic, and the working wavelength and the response intensity of the chiral optical element can be flexibly regulated and controlled.