An optical encryption(OE) scheme based on the spread spectrum ghost imaging(SSGI), named as SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadam...An optical encryption(OE) scheme based on the spread spectrum ghost imaging(SSGI), named as SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadamard matrix of order N is used as the secure key, and shared with the authorized user, Bob, through a private channel. Each corresponding row vector of the order-N Hadamard matrix is then used as the direct sequence code to modulate a speckle pattern for the ghost imaging system, and an image is encrypted with the help of the SSGI. The measurement results from the bucket detector, named as ciphertext, are then transmitted to Bob through a public channel. The illuminating speckle patterns are also shared with Bob by the public channel. With the correct secure key, Bob could reconstruct the image with the aid of the SSGI system, whereas the unauthorized user, Eve, could not obtain any useful information of the encrypted image. The numerical simulations and experimental results show that the proposed scheme is feasible with a higher security and a smaller key. For the 32 × 32 pixels image, the number of bits sent from Alice to Bob by using SSGIOE(M = 1024, N = 2048) scheme is only 0.0107 times over a computational ghost imaging optical encryption scheme.When the eavesdropping ratio(ER) is less than 40%, the eavesdropper cannot acquire any information of the encrypted image. The extreme circumstance for the proposed SSGI-OE scheme is also discussed, where the eavesdropper begins to extract the information when ER is up to 15%.展开更多
The growing demand for cryptographic security encourages the innovation of advanced materials with unique optical properties to secure information using light.Structural colors with soft materials exhibit dynamically ...The growing demand for cryptographic security encourages the innovation of advanced materials with unique optical properties to secure information using light.Structural colors with soft materials exhibit dynamically tunable optical properties in response to external stimuli,making them ideal for multi-level photonic encryption.However,most previous studies on structural color-based photonic encryption have predominantly focused on single-wavelength tuning while employing inadequate triggering methods for practical device applications.Here,we propose a chiral liquid crystal elastomer(CLCE)designed for stretching-induced multi-wavelength control to enhance photonic encryption functionality.By employing a heterogeneous configuration with thickness-modulated CLCE,we achieve multi-photonic band wavelength control under mechanical deformation.Furthermore,this method extends the tunable wavelength range beyond the visible spectrum into the infrared region and integrates a discrete multi-pixel array structure,enabling advanced spatial and spectral control for complex encryption schemes.This multi-wavelength modulation method is expected to provide significant potential for applications in photonic encryption,adaptive optics,and next-generation information security systems.展开更多
Optical encryption plays an increasingly important role in the field of information security owing to its parallel processing capability and low power consumption.Employing the ultrathin metasurfaces in optical encryp...Optical encryption plays an increasingly important role in the field of information security owing to its parallel processing capability and low power consumption.Employing the ultrathin metasurfaces in optical encryption has promoted the miniaturization and multifunctionality of encryption systems.Nevertheless,with the few number of degrees of freedom(DoFs)multiplexed by single metasurface,both key space and encoding space are limited.To address this issue,we propose a high-security and large-capacity optical encryption scheme based on perfect high-dimensional Poincare beams with expanded DoFs.By cascading two arrayed metasurfaces,more beam properties can be independently engineered,which gives rise to the extensively expanded key and encoding spaces.Our work provides a promising strategy for optical encryption with high security level and large information capacity and might facilitate the applications of Poincare beams in optical communications and quantum information.展开更多
Optical encryption strategies utilizing fully coherent light have been widely explored but often face challenges such as speckle noise and beam instabilities.In this work,we introduce a novel protocol for multi-channe...Optical encryption strategies utilizing fully coherent light have been widely explored but often face challenges such as speckle noise and beam instabilities.In this work,we introduce a novel protocol for multi-channel optical information encoding and encryption using vectorial spatial coherence engineering of a partially coherent light beam.By characterizing the beam’s spatial coherence structure with a 2×2 coherence matrix,we demonstrate independent control over the three components of the coherence Stokes vector.This allows for three-channel optical information encoding and encryption,with applications in color image representation.Unlike existing methods based on fully coherent light modulations,our approach utilizes a two-point dependent coherence Stokes vector,proving resilient to random noise in experimental scenarios.Our findings provide a robust foundation for higher-dimensional optical encoding and encryption,addressing limitations associated with partially coherent light in complex environments.展开更多
Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical e...Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical encryption systems but it is limited for practical applications since it requires a large set of plaintext-ciphertext pairs for the cryptosystem to be at-tacked.Here,we propose a two-step deep learning strategy for ciphertext-only attack(COA)on the classical double ran-dom phase encryption(DRPE).Specifically,we construct a virtual DRPE system to gather the training data.Besides,we divide the inverse problem in COA into two more specific inverse problems and employ two deep neural networks(DNNs)to respectively learn the removal of speckle noise in the autocorrelation domain and the de-correlation operation to retrieve the plaintext image.With these two trained DNNs at hand,we show that the plaintext can be predicted in real-time from an unknown ciphertext alone.The proposed learning-based COA method dispenses with not only the retrieval of random phase keys but also the invasive data acquisition of plaintext-ciphertext pairs in the DPRE system.Numerical simulations and optical experiments demonstrate the feasibility and effectiveness of the proposed learning-based COA method.展开更多
Cascaded holography coupled with the secret-sharing scheme has recently gained considerable attention due to its enhanced information processing and encryption capabilities.Here,we propose a new holographic iterative ...Cascaded holography coupled with the secret-sharing scheme has recently gained considerable attention due to its enhanced information processing and encryption capabilities.Here,we propose a new holographic iterative algorithm and present the implementation of cascaded liquid crystal(LC)holography for optical encryption.Each LC layer acts as the secret key and can generate a distinct holographic image.By cascading two LC elements,a new holographic image is formed.Additionally,we showcase the dynamic optical encryption achieved by electrically switching LCs with combined electric keys.This work may offer promising applications in optical cryptography,all-optical computing,and data storage.展开更多
Optical logic gates call for materials with giant optical nonlinearity to break the current performance bottleneck.Metal–organic frameworks(MOFs)provide an intriguing route to achieve superior optical nonlinearity be...Optical logic gates call for materials with giant optical nonlinearity to break the current performance bottleneck.Metal–organic frameworks(MOFs)provide an intriguing route to achieve superior optical nonlinearity benefitting from structural diversity and design flexibility.However,the potential of MOFs for optoelectronics has been largely overlooked and their applications in optical logic have not been exploited.Here,through temporally manipulating the nonlinear optical absorption process in porphyrin-based MOFs,we have successfully developed AND and XOR logic gates with an ultrafast speed approaching 1 THz and an on–off ratio above 90%.On this basis,all-optical information encryption is further demonstrated using transmittance as primary codes,which shows vast prospects in avoiding the disclosure of security information.To the best of our knowledge,this is the first exploration of MOFs for applications in ultrafast optical logic devices and information encryption.展开更多
Single-pixel imaging(SPI)enables an invisible target to be imaged onto a photosensitive surface without a lens,emerging as a promising way for indirect optical encryption.However,due to its linear and broadcast imagin...Single-pixel imaging(SPI)enables an invisible target to be imaged onto a photosensitive surface without a lens,emerging as a promising way for indirect optical encryption.However,due to its linear and broadcast imaging principles,SPI encryption has been confined to a single-user framework for the long term.We propose a multi-image SPI encryption method and combine it with orthogonal frequency division multiplexing-assisted key management,to achieve a multiuser SPI encryption and authentication framework.Multiple images are first encrypted as a composite intensity sequence containing the plaintexts and authentication information,simultaneously generating different sets of keys for users.Then,the SPI keys for encryption and authentication are asymmetrically isolated into independent frequency carriers and encapsulated into a Malus metasurface,so as to establish an individually private and content-independent channel for each user.Users can receive different plaintexts privately and verify the authenticity,eliminating the broadcast transparency of SPI encryption.The improved linear security is also verified by simulating attacks.By the combination of direct key management and indirect image encryption,our work achieves the encryption and authentication functionality under a multiuser computational imaging framework,facilitating its application in optical communication,imaging,and security.展开更多
Leveraging an optical system for image encryption is a promising approach to information security since one can enjoy parallel,high-speed transmission,and low-power consumption encryption features.However,most existin...Leveraging an optical system for image encryption is a promising approach to information security since one can enjoy parallel,high-speed transmission,and low-power consumption encryption features.However,most existing optical encryption systems involve a critical issue that the dimension of the ciphertexts is the same as the plaintexts,which may result in a cracking process with identical plaintextciphertext forms.Inspired by recent advances in computational neuromorphic imaging(CNI)and speckle correlography,a neuromorphic encryption technique is proposed and demonstrated through proof-ofprinciple experiments.The original images can be optically encrypted into event-stream ciphertext with a high-level information conversion form.To the best of our knowledge,the proposed method is the first implementation for event-driven optical image encryption.Due to the high level of encryption data with the CNI paradigm and the simple optical setup with a complex inverse scattering process,our solution has great potential for practical security applications.This method gives impetus to the image encryption of the visual information and paves the way for the CNI-informed applications of speckle correlography.展开更多
The principle of ptychography is applied in known plain text attack on the double random phase encoding （DRPE） system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can...The principle of ptychography is applied in known plain text attack on the double random phase encoding （DRPE） system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can be converted to the model of ptyehographical imaging. Owing to the inherent merits of the ptyehographical imaging, the DRPE system can be breached totally in a fast and nearly perfect way, which is unavailable for currently existing attack methods. Further, since the decryption keys can be seen as an object to be imaged from the perspective of imaging, the ptychographical technique may be a kind of new direction to further analysis of the security of other encryption systems based on double random keys.展开更多
Some existing image encryption schemes use simple low-dimensional chaotic systems, which makes the algorithms insecure and vulnerable to brute force attacks and cracking. Some algorithms have issues such as weak corre...Some existing image encryption schemes use simple low-dimensional chaotic systems, which makes the algorithms insecure and vulnerable to brute force attacks and cracking. Some algorithms have issues such as weak correlation with plaintext images, poor image reconstruction quality, and low efficiency in transmission and storage. To solve these issues,this paper proposes an optical image encryption algorithm based on a new four-dimensional memristive hyperchaotic system(4D MHS) and compressed sensing(CS). Firstly, this paper proposes a new 4D MHS, which has larger key space, richer dynamic behavior, and more complex hyperchaotic characteristics. The introduction of CS can reduce the image size and the transmission burden of hardware devices. The introduction of double random phase encoding(DRPE) enables this algorithm has the ability of parallel data processing and multi-dimensional coding space, and the hyperchaotic characteristics of 4D MHS make up for the nonlinear deficiency of DRPE. Secondly, a construction method of the deterministic chaotic measurement matrix(DCMM) is proposed. Using DCMM can not only save a lot of transmission bandwidth and storage space, but also ensure good quality of reconstructed images. Thirdly, the confusion method and diffusion method proposed are related to plaintext images, which require both four hyperchaotic sequences of 4D MHS and row and column keys based on plaintext images. The generation process of hyperchaotic sequences is closely related to the hash value of plaintext images. Therefore, this algorithm has high sensitivity to plaintext images. The experimental testing and comparative analysis results show that proposed algorithm has good security and effectiveness.展开更多
Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties o...Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties of an optical field is crucial for a wide range of applications.However,despite many proposed measurement schemes,significant challenges still remain.In this work,we present a protocol to measure the full-dimensional coherence properties of a partially coherent beam.The method is based on tomographing the complex coherent modes of the partially coherent field within its coherence time.Once the complex coherent modes are reconstructed,all coherence properties including field correlation and its higher-order correlations(e.g.,intensity correlation)can be recovered for beams that are either spatially uniformly or non-uniformly correlated.We perform a proof-of-principle experiment to measure the complex field correlation and intensity correlation of a structured partially coherent beam synthesized by random modes.Additionally,we discuss the application of full-dimensional complex coherence function tomography in coherence-based multi-cipher information security.The robustness of our system in complex environments is also evaluated.展开更多
In this paper, we propose an encryption scheme based on phase-shifting digital interferometry. According to the original system framework, we add a random amplitude mask and replace the Fourier transform by the Fresne...In this paper, we propose an encryption scheme based on phase-shifting digital interferometry. According to the original system framework, we add a random amplitude mask and replace the Fourier transform by the Fresnel transform. We develop a mathematical model and give a discrete formula based on the scheme, which makes it easy to implement the scheme in computer programming. The experimental results show that the improved system has a better performance in security than the original encryption method. Moreover, it demonstrates a good capability of anti-noise and anti-shear robustness.展开更多
A new distribution scheme of decryption keys used in optical verification systems is proposed. The encryption procedure is digitally implemented with the use of an iteration algorithm in computer. Three target images ...A new distribution scheme of decryption keys used in optical verification systems is proposed. The encryption procedure is digitally implemented with the use of an iteration algorithm in computer. Three target images corresponding to three wavelengths are encoded into three sets of phase-only masks （POMs） by a special distributing method. These three sets of POMs are assigned to three authorized users as the personal identification. A lensless optical system is used as the verification system. In the verification procedure, every two of the three authorized users can pass the verification procedure cooperatively, but only one user cannot do. Numerical simulation shows that the proposed distribution scheme of decryption keys not only can improve the security level of verification system, but also can bring convenience and flexibility for authorized users.展开更多
Due to the rapid growth of telemedicine and healthcare services,color medical image security applications have been expanded precipitously.In this paper,an asymmetric PTFrFT(Phase Truncated Fractional Fourier Transfor...Due to the rapid growth of telemedicine and healthcare services,color medical image security applications have been expanded precipitously.In this paper,an asymmetric PTFrFT(Phase Truncated Fractional Fourier Transform)-based color medical image cryptosystem is suggested.Two different phases in the fractional Fourier and output planes are provided as deciphering keys.Accordingly,the ciphering keys will not be employed for the deciphering procedure.Thus,the introduced PTFrFT algorithm comprises asymmetric ciphering and deciphering processes in contrast to the traditional optical symmetric OSH(Optical Scanning Holography)and DRPE(Double Random Phase Encoding)algorithms.One of the principal impacts of the introduced asymmetric cryptosystem is that it eliminates the onedimensionality aspects of the related symmetric cryptosystems due to its remarkable feature of phase nonlinear truncation components.More comparisons on various colormedical images are examined and analyzed to substantiate the cryptosystem efficacy.The achieved experimental outcomes ensure that the introduced cryptosystem is robust and secure.It has terrific cryptography performance compared to conventional cryptography algorithms,even in the presence of noise and severe channel attacks.展开更多
The optical coherence structures of random optical fields can determine beam propagation behavior,light–matter interactions,etc.Their performance makes a light beam robust against turbulence,scattering,and distortion...The optical coherence structures of random optical fields can determine beam propagation behavior,light–matter interactions,etc.Their performance makes a light beam robust against turbulence,scattering,and distortion.Recently,we proposed optical coherence encryption and robust far-field optical imaging techniques.All related applications place a high demand on precision in the experimental measurements of complex optical coherence structures,including their real and imaginary parts.Past studies on these measurements have mainly adopted theoretical mathematical approximations,limited to Gaussian statistic involving speckle statistic(time-consuming),or used complicated and delicate optical systems in the laboratory.In this study,we provide:a robust,convenient,and fast protocol to measure the optical coherence structures of random optical fields via generalized Arago(or Poisson)spot experiments with rigorous mathematical solutions.Our proposal only requires to capture the intensity thrice,and is applicable to any optical coherence structures,regardless of their type or optical statistics.The theoretical and experimental results demonstrated that the real and imaginary parts of the structures could be simultaneously recovered with high precision.We believe that such a protocol can be widely employed in phase measurement,optical imaging,and image transfer.展开更多
The two types of nonlinear optical cryptosystems(NOCs)that are respectively based on amplitude-phase retrieval algorithm(APRA)and phase retrieval algorithm(PRA)have attracted a lot of attention due to their unique mec...The two types of nonlinear optical cryptosystems(NOCs)that are respectively based on amplitude-phase retrieval algorithm(APRA)and phase retrieval algorithm(PRA)have attracted a lot of attention due to their unique mechanism of encryption process and remarkable ability to resist common attacks.In this paper,the securities of the two types of NOCs are evaluated by using a deep-learning(DL)method,where an end-to-end densely connected convolutional network(DenseNet)model for cryptanalysis is developed.The proposed DL-based method is able to retrieve unknown plaintexts from the given ciphertexts by using the trained DenseNet model without prior knowledge of any public or private key.The results of numerical experiments with the DenseNet model clearly demonstrate the validity and good performance of the proposed the DL-based attack on NOCs.展开更多
In the last few years,videos became the most common form of information transmitted over the internet,and a lot of the traffic is confidential and must be protected and delivered safely to its intended users.This intr...In the last few years,videos became the most common form of information transmitted over the internet,and a lot of the traffic is confidential and must be protected and delivered safely to its intended users.This introduces the challenges of presenting encryption systems that can encode videos securely and efficiently at the same time.This paper presents an efficient opto-video encryption system using Logistic Adjusted Sine map(LASM)in the Fractional Fourier Transform(FrFT).In the presented opto-video LASM-based FrFT scheme,the encoded video is split into distinct frames and transformed into optical signals utilizing an optical supply.Each of the developed optical video frames is ciphered by utilizing the LASM in optical FrFT system using two-phase modulation forms on the video frame,the first in the time-domain and the second in the FrFT domain.In the end,the ciphervideo frame is spotted utilizing a CCD digital camera and transformed into a digital structure that can be managed using a computer.We test the proposed opto-video LASM-based FrFT scheme using various security tools.The outcomes demonstrate that the presented scheme can effectively encrypt and decrypt video signals.In addition,it encrypts videos with a high level of encryption qualitywithout sacrificing its resistance to noise immunity.Finally,the test outcomes demonstrate that the presented scheme is immune to known attacks.展开更多
The second near-infrared(NIR-II,1000-1700 nm)circularly polarized light holds significant untapped potential in areas such as optical anti-counterfeiting and information encryption due to its deeply covert nature.Howe...The second near-infrared(NIR-II,1000-1700 nm)circularly polarized light holds significant untapped potential in areas such as optical anti-counterfeiting and information encryption due to its deeply covert nature.However,the typically low luminescence dissymmetry factor(glum)of circularly polarized luminescence(CPL)materials,particularly in NIR CPL materials,limits their practical application.Addressing this challenge,it is crucial to develop NIR CPL materials with enhanced glum.In this study,we present a series of chiral photonic micro-particles(CPMPs)with tunable chiral photonic bandgaps in the NIR-II range,capable of modulating NIR-II luminescent quantum dots to produce NIR CPL.These CPMPs not only impart chirality to the quantum dots,but also act as carriers,minimizing luminescence quenching from external environments.The tunable chiral photonic bandgap in CPMPs enables the generation of NIR CPL with a high|glum|value of up to 0.81,facilitating the advanced application in covert optical anti-counterfeiting.This work offers a straightforward and viable strategy for the development of NIR CPL materials,broadening their use in invisible information encryption and optical anti-counterfeiting technologies.展开更多
Layered Bi_(2)O_(2)Se nanosheets,characterized by a low bandgap,high electron mobility,and good air stability,have garnered significant attention for their potential applications in electronics and photonics.However,t...Layered Bi_(2)O_(2)Se nanosheets,characterized by a low bandgap,high electron mobility,and good air stability,have garnered significant attention for their potential applications in electronics and photonics.However,the relatively low photocurrent generated by single Bi_(2)O_(2)Se nanosheet photodetectors results in diminished switching ratios and responsiveness,thereby limiting the overall performance of Bi_(2)O_(2)Se-based photodetectors.In this study,we report a dual-band heterostructure photodetector constructed from high-quality Bi_(2)O_(2)Se nanosheets and CdS nanobelts.This device demonstrates exceptional photodetection performance in both the visible(450 nm)and near-infrared(1150 nm)regions,featuring a high switching ratio,increased responsivity,elevated specific detectivity,large external quantum efficiency,and rapid response speed.Notably,these key parameters exceed those reported in most Bi_(2)O_(2)Se-based photodetectors.Importantly,the Bi_(2)O_(2)Se/CdS heterostructure photodetector showcases impressive high-resolution imaging capabilities.These findings highlight the promising potential of this device for applications in image sensing and encrypted optical communication.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61871234 and 62001249)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX200729)+3 种基金the Natural Science Research Project of Higher Education of Jiangsu Province(Grant No.20KJB510030)the Qing Lan Project of Jiangsu Province(Su Teacher’s Letter[2022]No.29)the Research project of NanJing Tech University Pujiang Institute(Grant No.njpj2022-1-25)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘An optical encryption(OE) scheme based on the spread spectrum ghost imaging(SSGI), named as SSGI-OE, is proposed to obtain a high security with a smaller key. In the scheme, the randomly selected row number of a Hadamard matrix of order N is used as the secure key, and shared with the authorized user, Bob, through a private channel. Each corresponding row vector of the order-N Hadamard matrix is then used as the direct sequence code to modulate a speckle pattern for the ghost imaging system, and an image is encrypted with the help of the SSGI. The measurement results from the bucket detector, named as ciphertext, are then transmitted to Bob through a public channel. The illuminating speckle patterns are also shared with Bob by the public channel. With the correct secure key, Bob could reconstruct the image with the aid of the SSGI system, whereas the unauthorized user, Eve, could not obtain any useful information of the encrypted image. The numerical simulations and experimental results show that the proposed scheme is feasible with a higher security and a smaller key. For the 32 × 32 pixels image, the number of bits sent from Alice to Bob by using SSGIOE(M = 1024, N = 2048) scheme is only 0.0107 times over a computational ghost imaging optical encryption scheme.When the eavesdropping ratio(ER) is less than 40%, the eavesdropper cannot acquire any information of the encrypted image. The extreme circumstance for the proposed SSGI-OE scheme is also discussed, where the eavesdropper begins to extract the information when ER is up to 15%.
基金supported by the Samsung Research Funding&Incubation Center of Samsung Electronics under Project Number SRFC-TC2103-01Technology Innovation Program(20010690)funded by the Ministry of Trade,Industry and Energy(MOTIE,Korea)+1 种基金Samsung Electronics Co Ltd,grant number IO201211-08048-01the BK21 FOUR Program for Educational Institute for Intelligent Information Integration of the National Research Foundation of Korea(NRF)grant funded by the Korea government.
文摘The growing demand for cryptographic security encourages the innovation of advanced materials with unique optical properties to secure information using light.Structural colors with soft materials exhibit dynamically tunable optical properties in response to external stimuli,making them ideal for multi-level photonic encryption.However,most previous studies on structural color-based photonic encryption have predominantly focused on single-wavelength tuning while employing inadequate triggering methods for practical device applications.Here,we propose a chiral liquid crystal elastomer(CLCE)designed for stretching-induced multi-wavelength control to enhance photonic encryption functionality.By employing a heterogeneous configuration with thickness-modulated CLCE,we achieve multi-photonic band wavelength control under mechanical deformation.Furthermore,this method extends the tunable wavelength range beyond the visible spectrum into the infrared region and integrates a discrete multi-pixel array structure,enabling advanced spatial and spectral control for complex encryption schemes.This multi-wavelength modulation method is expected to provide significant potential for applications in photonic encryption,adaptive optics,and next-generation information security systems.
基金provided by National Key Research and Development Program of China(2022YFA1404301)National Natural Science Foundation of China(Nos.62325504,62305149,92250304,62288101)+1 种基金Dengfeng Project B of Nanjing Universitythe micro-fabrication center of the National Laboratory of Solid State Microstructures(NLSSM)for technique support。
文摘Optical encryption plays an increasingly important role in the field of information security owing to its parallel processing capability and low power consumption.Employing the ultrathin metasurfaces in optical encryption has promoted the miniaturization and multifunctionality of encryption systems.Nevertheless,with the few number of degrees of freedom(DoFs)multiplexed by single metasurface,both key space and encoding space are limited.To address this issue,we propose a high-security and large-capacity optical encryption scheme based on perfect high-dimensional Poincare beams with expanded DoFs.By cascading two arrayed metasurfaces,more beam properties can be independently engineered,which gives rise to the extensively expanded key and encoding spaces.Our work provides a promising strategy for optical encryption with high security level and large information capacity and might facilitate the applications of Poincare beams in optical communications and quantum information.
基金National Key Research and Development Program of China(2022YFA1404800,2019YFA0705000)National Natural Science Foundation of China(11974218,12192254,12274310,12274311,92250304,12347114)Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB185).
文摘Optical encryption strategies utilizing fully coherent light have been widely explored but often face challenges such as speckle noise and beam instabilities.In this work,we introduce a novel protocol for multi-channel optical information encoding and encryption using vectorial spatial coherence engineering of a partially coherent light beam.By characterizing the beam’s spatial coherence structure with a 2×2 coherence matrix,we demonstrate independent control over the three components of the coherence Stokes vector.This allows for three-channel optical information encoding and encryption,with applications in color image representation.Unlike existing methods based on fully coherent light modulations,our approach utilizes a two-point dependent coherence Stokes vector,proving resilient to random noise in experimental scenarios.Our findings provide a robust foundation for higher-dimensional optical encoding and encryption,addressing limitations associated with partially coherent light in complex environments.
基金financial supports from the National Natural Science Foundation of China(NSFC)(62061136005,61705141,61805152,61875129,61701321)Sino-German Research Collaboration Group(GZ 1391)+2 种基金the Mobility program(M-0044)sponsored by the Sino-German CenterChinese Academy of Sciences(QYZDB-SSW-JSC002)Science and Technology Innovation Commission of Shenzhen(JCYJ20170817095047279)。
文摘Optical cryptanalysis is essential to the further investigation of more secure optical cryptosystems.Learning-based at-tack of optical encryption eliminates the need for the retrieval of random phase keys of optical encryption systems but it is limited for practical applications since it requires a large set of plaintext-ciphertext pairs for the cryptosystem to be at-tacked.Here,we propose a two-step deep learning strategy for ciphertext-only attack(COA)on the classical double ran-dom phase encryption(DRPE).Specifically,we construct a virtual DRPE system to gather the training data.Besides,we divide the inverse problem in COA into two more specific inverse problems and employ two deep neural networks(DNNs)to respectively learn the removal of speckle noise in the autocorrelation domain and the de-correlation operation to retrieve the plaintext image.With these two trained DNNs at hand,we show that the plaintext can be predicted in real-time from an unknown ciphertext alone.The proposed learning-based COA method dispenses with not only the retrieval of random phase keys but also the invasive data acquisition of plaintext-ciphertext pairs in the DPRE system.Numerical simulations and optical experiments demonstrate the feasibility and effectiveness of the proposed learning-based COA method.
基金supported by the National Key Research and Development Program of China(Nos.2022YFA1405000 and 2021YFA1202000)the National Natural Science Foundation of China(Nos.52003115,62375119,62305157,and 62005009)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20212004)the support of Xiaomi Young Scholar ProgramYoung Elite Scientists Sponsorship Program by CAST(No.2022QNRC001).
文摘Cascaded holography coupled with the secret-sharing scheme has recently gained considerable attention due to its enhanced information processing and encryption capabilities.Here,we propose a new holographic iterative algorithm and present the implementation of cascaded liquid crystal(LC)holography for optical encryption.Each LC layer acts as the secret key and can generate a distinct holographic image.By cascading two LC elements,a new holographic image is formed.Additionally,we showcase the dynamic optical encryption achieved by electrically switching LCs with combined electric keys.This work may offer promising applications in optical cryptography,all-optical computing,and data storage.
基金supported by Science Challenge Project(no.TZ2018001)National Natural Science Foundation of China(nos.11872058 and 21802036)Project of State Key Laboratory of Environment-friendly Energy Materials,and Southwest University of Science and Technology(21fksy07).
文摘Optical logic gates call for materials with giant optical nonlinearity to break the current performance bottleneck.Metal–organic frameworks(MOFs)provide an intriguing route to achieve superior optical nonlinearity benefitting from structural diversity and design flexibility.However,the potential of MOFs for optoelectronics has been largely overlooked and their applications in optical logic have not been exploited.Here,through temporally manipulating the nonlinear optical absorption process in porphyrin-based MOFs,we have successfully developed AND and XOR logic gates with an ultrafast speed approaching 1 THz and an on–off ratio above 90%.On this basis,all-optical information encryption is further demonstrated using transmittance as primary codes,which shows vast prospects in avoiding the disclosure of security information.To the best of our knowledge,this is the first exploration of MOFs for applications in ultrafast optical logic devices and information encryption.
基金supported by the National Key R&D Program of China(Grant No.2021YFB3900300)National Natural Science Foundation of China(Grant Nos.61860206007,62275177,and 62371321)+4 种基金Ministry of Education Science and Technology Chunhui Project(Grant No.HZKY20220559)International S and T Cooperation Program of Sichuan Province(Grant No.2023YFH0030)Sichuan Science and Technology Innovation Seeding Project(Grant No.23-YCG034)Sichuan Science and Technology Program(Grant No.2023YFG0334)Chengdu Science and Technology Program(Grant No.2022-GH02-00001-HZ).
文摘Single-pixel imaging(SPI)enables an invisible target to be imaged onto a photosensitive surface without a lens,emerging as a promising way for indirect optical encryption.However,due to its linear and broadcast imaging principles,SPI encryption has been confined to a single-user framework for the long term.We propose a multi-image SPI encryption method and combine it with orthogonal frequency division multiplexing-assisted key management,to achieve a multiuser SPI encryption and authentication framework.Multiple images are first encrypted as a composite intensity sequence containing the plaintexts and authentication information,simultaneously generating different sets of keys for users.Then,the SPI keys for encryption and authentication are asymmetrically isolated into independent frequency carriers and encapsulated into a Malus metasurface,so as to establish an individually private and content-independent channel for each user.Users can receive different plaintexts privately and verify the authenticity,eliminating the broadcast transparency of SPI encryption.The improved linear security is also verified by simulating attacks.By the combination of direct key management and indirect image encryption,our work achieves the encryption and authentication functionality under a multiuser computational imaging framework,facilitating its application in optical communication,imaging,and security.
基金supported by the Research Grants Council of Hong Kong(GRF 17201620)ACCESS—AI Chip Center for Emerging Smart Systems,sponsored by InnoHK funding,Hong Kong,China,the National Natural Science Foundation of China(Grant Nos.62031018 and 61971227)Hong Kong Scholars Program(Grant No.XJ2022032).
文摘Leveraging an optical system for image encryption is a promising approach to information security since one can enjoy parallel,high-speed transmission,and low-power consumption encryption features.However,most existing optical encryption systems involve a critical issue that the dimension of the ciphertexts is the same as the plaintexts,which may result in a cracking process with identical plaintextciphertext forms.Inspired by recent advances in computational neuromorphic imaging(CNI)and speckle correlography,a neuromorphic encryption technique is proposed and demonstrated through proof-ofprinciple experiments.The original images can be optically encrypted into event-stream ciphertext with a high-level information conversion form.To the best of our knowledge,the proposed method is the first implementation for event-driven optical image encryption.Due to the high level of encryption data with the CNI paradigm and the simple optical setup with a complex inverse scattering process,our solution has great potential for practical security applications.This method gives impetus to the image encryption of the visual information and paves the way for the CNI-informed applications of speckle correlography.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61575197 and 61307018the K.C.Wong Education Foundation,the President Fund of University of Chinese Academy of Sciencesthe Fusion Funds of Research and Education of Chinese Academy of Sciences
文摘The principle of ptychography is applied in known plain text attack on the double random phase encoding （DRPE） system. We find that with several pairs of plain texts and cipher texts, the model of attack on DRPE can be converted to the model of ptyehographical imaging. Owing to the inherent merits of the ptyehographical imaging, the DRPE system can be breached totally in a fast and nearly perfect way, which is unavailable for currently existing attack methods. Further, since the decryption keys can be seen as an object to be imaged from the perspective of imaging, the ptychographical technique may be a kind of new direction to further analysis of the security of other encryption systems based on double random keys.
文摘Some existing image encryption schemes use simple low-dimensional chaotic systems, which makes the algorithms insecure and vulnerable to brute force attacks and cracking. Some algorithms have issues such as weak correlation with plaintext images, poor image reconstruction quality, and low efficiency in transmission and storage. To solve these issues,this paper proposes an optical image encryption algorithm based on a new four-dimensional memristive hyperchaotic system(4D MHS) and compressed sensing(CS). Firstly, this paper proposes a new 4D MHS, which has larger key space, richer dynamic behavior, and more complex hyperchaotic characteristics. The introduction of CS can reduce the image size and the transmission burden of hardware devices. The introduction of double random phase encoding(DRPE) enables this algorithm has the ability of parallel data processing and multi-dimensional coding space, and the hyperchaotic characteristics of 4D MHS make up for the nonlinear deficiency of DRPE. Secondly, a construction method of the deterministic chaotic measurement matrix(DCMM) is proposed. Using DCMM can not only save a lot of transmission bandwidth and storage space, but also ensure good quality of reconstructed images. Thirdly, the confusion method and diffusion method proposed are related to plaintext images, which require both four hyperchaotic sequences of 4D MHS and row and column keys based on plaintext images. The generation process of hyperchaotic sequences is closely related to the hash value of plaintext images. Therefore, this algorithm has high sensitivity to plaintext images. The experimental testing and comparative analysis results show that proposed algorithm has good security and effectiveness.
基金supports from the National Key Research and Development Project of China(2022YFA1404800)the National Natural Science Foundation of China(NSFC)(12404348,12347114,12274311,12274310,12192254,92250304,W2441005)+1 种基金the China Postdoctoral Science Foundation(2024M752311)the Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB185).
文摘Optical coherence is a fundamental property of light,playing a key role in understanding interference,propagation,and light-matter interactions for both classical and quantum light.Measuring the coherence properties of an optical field is crucial for a wide range of applications.However,despite many proposed measurement schemes,significant challenges still remain.In this work,we present a protocol to measure the full-dimensional coherence properties of a partially coherent beam.The method is based on tomographing the complex coherent modes of the partially coherent field within its coherence time.Once the complex coherent modes are reconstructed,all coherence properties including field correlation and its higher-order correlations(e.g.,intensity correlation)can be recovered for beams that are either spatially uniformly or non-uniformly correlated.We perform a proof-of-principle experiment to measure the complex field correlation and intensity correlation of a structured partially coherent beam synthesized by random modes.Additionally,we discuss the application of full-dimensional complex coherence function tomography in coherence-based multi-cipher information security.The robustness of our system in complex environments is also evaluated.
基金supported by the National Basic Research Program of China(Grant No.2011CB302903)the National Natural Science Foundation of China(Grant Nos.61272084 and 61202004)the Key Project of Natural Science Research of Jiangsu University,China(Grant No.11KJA520002)
文摘In this paper, we propose an encryption scheme based on phase-shifting digital interferometry. According to the original system framework, we add a random amplitude mask and replace the Fourier transform by the Fresnel transform. We develop a mathematical model and give a discrete formula based on the scheme, which makes it easy to implement the scheme in computer programming. The experimental results show that the improved system has a better performance in security than the original encryption method. Moreover, it demonstrates a good capability of anti-noise and anti-shear robustness.
文摘A new distribution scheme of decryption keys used in optical verification systems is proposed. The encryption procedure is digitally implemented with the use of an iteration algorithm in computer. Three target images corresponding to three wavelengths are encoded into three sets of phase-only masks （POMs） by a special distributing method. These three sets of POMs are assigned to three authorized users as the personal identification. A lensless optical system is used as the verification system. In the verification procedure, every two of the three authorized users can pass the verification procedure cooperatively, but only one user cannot do. Numerical simulation shows that the proposed distribution scheme of decryption keys not only can improve the security level of verification system, but also can bring convenience and flexibility for authorized users.
基金This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-track Research Funding Program to support publication in the top journal(Grant no.42-FTTJ-12).
文摘Due to the rapid growth of telemedicine and healthcare services,color medical image security applications have been expanded precipitously.In this paper,an asymmetric PTFrFT(Phase Truncated Fractional Fourier Transform)-based color medical image cryptosystem is suggested.Two different phases in the fractional Fourier and output planes are provided as deciphering keys.Accordingly,the ciphering keys will not be employed for the deciphering procedure.Thus,the introduced PTFrFT algorithm comprises asymmetric ciphering and deciphering processes in contrast to the traditional optical symmetric OSH(Optical Scanning Holography)and DRPE(Double Random Phase Encoding)algorithms.One of the principal impacts of the introduced asymmetric cryptosystem is that it eliminates the onedimensionality aspects of the related symmetric cryptosystems due to its remarkable feature of phase nonlinear truncation components.More comparisons on various colormedical images are examined and analyzed to substantiate the cryptosystem efficacy.The achieved experimental outcomes ensure that the introduced cryptosystem is robust and secure.It has terrific cryptography performance compared to conventional cryptography algorithms,even in the presence of noise and severe channel attacks.
基金This work was supported by the National Key Research and Development Program of China(2022YFA1404800,2019YFA0705000)National Natural Science Foundation of China(11974218,12004220,12104264,12192254,92250304)+2 种基金Regional Science and Technology Development Project of the Central Government(YDZX20203700001766)China Postdoctoral Science Foundation(2022T150392)the Natural Science Foundation of Shandong Province(ZR2021QA014,ZR2021ZD02).
文摘The optical coherence structures of random optical fields can determine beam propagation behavior,light–matter interactions,etc.Their performance makes a light beam robust against turbulence,scattering,and distortion.Recently,we proposed optical coherence encryption and robust far-field optical imaging techniques.All related applications place a high demand on precision in the experimental measurements of complex optical coherence structures,including their real and imaginary parts.Past studies on these measurements have mainly adopted theoretical mathematical approximations,limited to Gaussian statistic involving speckle statistic(time-consuming),or used complicated and delicate optical systems in the laboratory.In this study,we provide:a robust,convenient,and fast protocol to measure the optical coherence structures of random optical fields via generalized Arago(or Poisson)spot experiments with rigorous mathematical solutions.Our proposal only requires to capture the intensity thrice,and is applicable to any optical coherence structures,regardless of their type or optical statistics.The theoretical and experimental results demonstrated that the real and imaginary parts of the structures could be simultaneously recovered with high precision.We believe that such a protocol can be widely employed in phase measurement,optical imaging,and image transfer.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61975185 and 61575178)the Natural Science Foundation of Zhejiang Province,China(Grant No.LY19F030004)the Scientific Research and Development Fund of Zhejiang University of Science and Technology,China(Grant No.F701108L03).
文摘The two types of nonlinear optical cryptosystems(NOCs)that are respectively based on amplitude-phase retrieval algorithm(APRA)and phase retrieval algorithm(PRA)have attracted a lot of attention due to their unique mechanism of encryption process and remarkable ability to resist common attacks.In this paper,the securities of the two types of NOCs are evaluated by using a deep-learning(DL)method,where an end-to-end densely connected convolutional network(DenseNet)model for cryptanalysis is developed.The proposed DL-based method is able to retrieve unknown plaintexts from the given ciphertexts by using the trained DenseNet model without prior knowledge of any public or private key.The results of numerical experiments with the DenseNet model clearly demonstrate the validity and good performance of the proposed the DL-based attack on NOCs.
基金The authors would like to thank the Deanship of Scientific Research,Taif University Researchers Supporting Project Number(TURSP-2020/08),Taif University,Taif,Saudi Arabia for supporting this research work.
文摘In the last few years,videos became the most common form of information transmitted over the internet,and a lot of the traffic is confidential and must be protected and delivered safely to its intended users.This introduces the challenges of presenting encryption systems that can encode videos securely and efficiently at the same time.This paper presents an efficient opto-video encryption system using Logistic Adjusted Sine map(LASM)in the Fractional Fourier Transform(FrFT).In the presented opto-video LASM-based FrFT scheme,the encoded video is split into distinct frames and transformed into optical signals utilizing an optical supply.Each of the developed optical video frames is ciphered by utilizing the LASM in optical FrFT system using two-phase modulation forms on the video frame,the first in the time-domain and the second in the FrFT domain.In the end,the ciphervideo frame is spotted utilizing a CCD digital camera and transformed into a digital structure that can be managed using a computer.We test the proposed opto-video LASM-based FrFT scheme using various security tools.The outcomes demonstrate that the presented scheme can effectively encrypt and decrypt video signals.In addition,it encrypts videos with a high level of encryption qualitywithout sacrificing its resistance to noise immunity.Finally,the test outcomes demonstrate that the presented scheme is immune to known attacks.
基金supported by Beijing Natural Science Foundation(No.JQ21003)the National Key Basic R&D Research Program of Ministry of Science and Technology of the People’s Republic of China(No.2021YFA1200303)the National Natural Science Foundation of China(Nos.22302046,22172041,52173159,92256304,and 22271308).
文摘The second near-infrared(NIR-II,1000-1700 nm)circularly polarized light holds significant untapped potential in areas such as optical anti-counterfeiting and information encryption due to its deeply covert nature.However,the typically low luminescence dissymmetry factor(glum)of circularly polarized luminescence(CPL)materials,particularly in NIR CPL materials,limits their practical application.Addressing this challenge,it is crucial to develop NIR CPL materials with enhanced glum.In this study,we present a series of chiral photonic micro-particles(CPMPs)with tunable chiral photonic bandgaps in the NIR-II range,capable of modulating NIR-II luminescent quantum dots to produce NIR CPL.These CPMPs not only impart chirality to the quantum dots,but also act as carriers,minimizing luminescence quenching from external environments.The tunable chiral photonic bandgap in CPMPs enables the generation of NIR CPL with a high|glum|value of up to 0.81,facilitating the advanced application in covert optical anti-counterfeiting.This work offers a straightforward and viable strategy for the development of NIR CPL materials,broadening their use in invisible information encryption and optical anti-counterfeiting technologies.
基金supported by the National Natural Science Foundation of China(Nos.62464014,12464025,12264056,and 12264057)the Basic Research Program of Yunnan Province(No.202401AT070134)+2 种基金Project for Building a Science and Technology Innovation Center Facing South Asia and Southeast Asia(No.202403AP140015)Spring City Plan:The High-level Talent Promotion and Training Project of Kunming(No.2022SCP005)Yunnan Expert Workstation(No.202205AF150008).
文摘Layered Bi_(2)O_(2)Se nanosheets,characterized by a low bandgap,high electron mobility,and good air stability,have garnered significant attention for their potential applications in electronics and photonics.However,the relatively low photocurrent generated by single Bi_(2)O_(2)Se nanosheet photodetectors results in diminished switching ratios and responsiveness,thereby limiting the overall performance of Bi_(2)O_(2)Se-based photodetectors.In this study,we report a dual-band heterostructure photodetector constructed from high-quality Bi_(2)O_(2)Se nanosheets and CdS nanobelts.This device demonstrates exceptional photodetection performance in both the visible(450 nm)and near-infrared(1150 nm)regions,featuring a high switching ratio,increased responsivity,elevated specific detectivity,large external quantum efficiency,and rapid response speed.Notably,these key parameters exceed those reported in most Bi_(2)O_(2)Se-based photodetectors.Importantly,the Bi_(2)O_(2)Se/CdS heterostructure photodetector showcases impressive high-resolution imaging capabilities.These findings highlight the promising potential of this device for applications in image sensing and encrypted optical communication.
