Most of the existing carbon dot (CD)-based afterglow materials are limited to a single emission mode of either room-temperature phosphorescence (RTP) or delayed fluorescence (DF), which makes it difficult to meet the application requirements of advanced anti-counterfeiting and multi-level information encryption. Therefore, the development of CD-based composite materials with multi-mode afterglow emission, long lifetime and high stability holds significant research significance and application value. In this study, long-afterglow manganese/nitrogen co-doped CDs@boric acid (BA) composites (Mn, N-CDs @BA) are successfully prepared, and their optical properties and emission mechanism are clarified. The results demonstrate that the Mn, N-CDs @BA composites exhibit wavelength-dependent dual-afterglow emission characteristics of RTP and DF. Under 254 nm ultraviolet (UV) light excitation, they exhibit DF emission with an average lifetime of 903.36 ms. Under 365 nm UV light excitation, RTP emission with an average lifetime of 354.43 ms is observed. Moreover, the afterglow color exhibits time dependence. Based on the triple emission modes (fluorescence, RTP and DF) of the Mn, N-CDs @BA composites, optical patterns were designed and fabricated, and counterfeit-resistant and unclonable anti-counterfeiting and high concealment information encryption were successfully achieved. This work develops a potentially feasible approach for next-generation advanced optical anti-counterfeiting and information encryption systems.

Organizations usually rely on stringent access control mechanisms where access policies are an important asset. Their storage or transmission in plaintext can compromise sensitive access rules. It is important in dynamic environments where access decisions are made in real time such as Zero Trust (ZT). Existing ZT approaches were found to oversee the aspect of securing these policies. This investigation presents a Multi-layer Access Policy Encryption System for ZT systems (MAPE-ZT). The first stage uses the trapdoor index to generate a secure index to find the applicable access policies. Advanced Encryption Standard-256 is used in counter mode for the encryption of the policies. They are re-encrypted using the Ciphertext-Policy Attribute-Based Encryption (CP-ABE) to allow decryption based on a matching set of attributes. Various experiments using quantitative metrics, including comparison with baseline access control systems simulation, scalability evaluation, storage overhead, etc., highlight the efficacy of the MAPE-ZT and establish new benchmarks. The result count entropy for the policies ranged 3.84–4.21 for different scales of policies. The evaluation in different scales of systems shows that the MAPE-ZT reduces various observable patterns even if the deployment size grows. Its unique design of securing policies makes this approach scalable for multi-domain integration.

Multi-stimuli-responsive lanthanide metallogels with chromic behaviors for time-resolved information encryption and anti-counterfeiting.

Developing anisotropic force-induced hypso- and bathochromic bidirectional fluorescence switches based on pyrene-functionalized fluorene luminogens through manipulating steric hindrance.

ABSTRACT With the rapid development of X‐ray technologies in medical imaging, non‐destructive testing, and anti‐counterfeiting, there is an urgent demand for multimode visual detection. Here, Tb 3+ /Eu 3+ ‐doped Ba 2 LuTaO 6 perovskites were synthesized via solid‐state reaction, showing distinct green and red emissions under UV or X‐ray excitation, with co‐doping enabling tunable yellow‐to‐red luminescence. Eu 3+ ‐doped Ba 2 LuTaO 6 exhibited reversible X‐ray‐induced photochromism with nearly full thermal recovery (200°C, 5 min) and a 68% photoluminescence modulation depth. The photochromic response enabled cumulative visual dosimetry, while radioluminescence intensity scaled linearly with dose rate, supporting real‐time monitoring. Different dopants yielded distinct colors and markedly different light yields, enabling color‐visualized dose detectors for radiation warning. Mechanistic studies confirmed oxygen‐vacancy‐related color centers as the origin of photochromism and multipolar energy transfer as the basis of tunable luminescence. Incorporation of phosphors into polydimethylsiloxane produced flexible scintillator films for high‐resolution X‐ray 3D imaging. A proof‐of‐concept encryption system, integrating luminescence modulation and X‐ray imaging, further demonstrated strong anti‐counterfeiting performance. This multifunctional platform advances flexible imaging, radiation detection, and secure information encryption.

Indistinguishability is a fundamental principle of cryptographic security, crucial for securing data transmitted between Internet of Things (IoT) devices. This principle ensures that an attacker cannot distinguish between the encrypted data, also known as ciphertext, and random data or the ciphertexts of two messages encrypted with the same key. This research investigates the ability of machine learning (ML) to assess the indistinguishability property in encryption systems, with a focus on lightweight ciphers. As our first case study, we consider the SPECK32/64 and SIMON32/64 lightweight block ciphers, designed for IoT devices operating under significant energy constraints. In this research, we introduce MIND-Crypt (a Machine-learning-based framework for assessing the INDistinguishability of Cryptographic algorithms), a novel ML-based framework designed to assess the cryptographic indistinguishability of lightweight block ciphers, specifically the SPECK32/64 and SIMON32/64 encryption algorithms in CBC, CFB, OFB, and CTR modes, under Known Plaintext Attacks (KPAs). Our approach involves training ML models using ciphertexts from two plaintext messages encrypted with the same key to determine whether ML algorithms can identify meaningful cryptographic patterns or leakage. Our experiments show that modern ML techniques consistently achieve accuracy equivalent to random guessing, indicating that no statistically exploitable patterns exist in the ciphertexts generated by the considered lightweight block ciphers. Although some models exhibit mode-dependent bias (e.g., collapsing to a single-class prediction in CBC and CFB), their overall accuracy remains at random guessing levels, reinforcing that no meaningful distinguishing patterns are learned. Furthermore, we demonstrate that, when ML algorithms are trained on all possible combinations of ciphertexts for given plaintext messages, their behavior reflects memorization rather than generalization to unseen ciphertexts. Collectively, these findings suggest that existing block ciphers have secure cryptographic designs against ML-based indistinguishability assessments, reinforcing their security even under round-reduced conditions.

Most of the nonalkali MOFs containing NDI only turn darken after photoresponse, with a narrow color change range. To expand the color response range of photochromic materials, this work designs two novel metal-organic frameworks (Na/Cs-CMNDI) constructed by alkali metals (Na+, Cs+) and the photoresponsive linker N, N'-bis(carboxymethyl)-1,4,5,8-naphthalenedicarboximide (H2CMNDI). It was found that the thermally stable Cs-CMNDI exhibits a remarkable four-color transformation from yellow, gray to black and finally red under photothermal costimulation, surpassing the limitation of single-color change in traditional NDI-based MOFs. Based on this, a dynamic information encryption system was successfully established, which can generate specific passwords within a certain period of time, and a color-based encryption strategy was developed by using an 8888-type mold to brush the powder to encrypt specific four-digit numbers. Moreover, both AMOFs can be used as fluorescent sensors for the detection of the antibiotic cefuroxime, demonstrating good application potential in the fields of medicine and ecological protection.

The SecureSustainNet Framework- a novel technique for enhancing security and sustainability in data centers is introduced in this paper. Given the security and sustainability concerns with data centers, this paper tackles the challenge of balancing data center security and energy efficiency. Existing solutions are unable to provide the required security level without large processing and power costs. States existing approaches that combine efficient resource utilization with high security performance is identified as a research gap. The multi-objective optimization of those approaches is designed to incorporate energy, efficient techniques and security functionalities. The approach has 6 main algorithms; Intrusion Detection System with Anomaly Detection; AES, 256 encryptions with virtualization, based key management; Role Based Access Control RBAC with dynamic policy tuning; dynamic resource allocation; energy consumption monitoring and management; and renewable source integration. The framework has been implemented into the network simulator ns, 3. A remarkably high 98.7% Anomaly Detection Rate ADR was elicited through an interpreter Intrusion Detection System IDS against Gaussian Mixture Models GMM, 6.4% above existing approaches, with a mean 0.4% False Positive Rate FPR. It achieved a 2.5% increase in processing time due to its AES, 256 Encryption system through which employ a dynamically managed key management system. It attained a 97.4% Access Control Effectiveness (ACE) and an 8.8% increase against traditional models through its dynamic policy adaptations based on user context. It obtained an 85.2% Resource Utilization Efficiency RUE and a 7% increase over its competitors while reducing the energy consumption by 15.6% through its efficient resource utilization. The power usage effectiveness PUE of the system was calculated as 1.25, a far cry from current models that achieved it as high as 1.47

Lanthanide ions (Ln3+) doped upconversion originates from their diverse 4f electron transitions. However, the direct manipulation of excited-state electron populations for dynamic emission modulation remains challenging. In this study, a cross-relaxation control paradigm, enabled by dual-wavelength cooperative excitation, is developed for dynamic upconversion engineering. The Er3+-Ln3+ (Ln3+ = Tm3+, Ho3+, Yb3+) doped NaYS2 platform precisely populates the dual-target energy levels via cross-relaxation pathways under cooperative excitation. This approach enables dynamic green-to-red luminescence switching while amplifying the red emission (∼20-fold) by accelerating the cross-relaxation kinetics; Er3+ acts as the photon harvester, and Ln3+ serves as the cross-relaxation mediator to redirect population fluxes. The experimental and theoretical results demonstrate that this phenomenon originates from the unique properties of the low phonon energy, unique layered structure with a large interionic spacing, and high refractive index of the NaYS2 host. Finally, programmable upconversion logic gate arrays are implemented to develop a dynamic- random-visual encryption system for optical information security. This study establishes a novel paradigm for upconversion manipulation with unprecedented capabilities for advanced information technologies.

The exponential growth of digital data and the escalating sophistication of cyber threats have intensified the demand for secure yet computationally efficient encryption methods. Conventional algorithms (e.g., AES-based schemes) are cryptographically strong and widely deployed; however, some implementations can face performance bottlenecks in large-scale or real-time workloads. While many modern systems seed from hardware entropy sources and employ standardized cryptographic PRNGs/DRBGs, security can still be degraded in practice by weak entropy initialization, misconfiguration, or the use of non-cryptographic deterministic generators in certain environments. To address these gaps, this study introduces FileCipher. This novel file-encryption framework integrates a chaos-enhanced Cryptographically Secure Pseudorandom Number Generator (CPRNG) based on the State-Based Tent Map (SBTM). The proposed design achieves a balanced trade-off between security and efficiency through dynamic key generation, adaptive block reshaping, and structured confusion–diffusion processes. The SBTM-driven CPRNG introduces adaptive seeding and multi-key feedback, ensuring high entropy and sensitivity to initial conditions. A multi-threaded Java implementation demonstrates approximately 60% reduction in encryption time compared with AES-CBC, validating FileCipher’s scalability in parallel execution environments. Statistical evaluations using NIST SP 800-22, SP 800-90B, Dieharder, and TestU01 confirm superior randomness with over 99% pass rates, while Avalanche Effect analysis indicates bit-change ratios near 50%, proving strong diffusion characteristics. The results highlight FileCipher’s novelty in combining nonlinear chaotic dynamics with lightweight parallel architecture, offering a robust, platform-independent solution for secure data storage and transmission. Ultimately, this paper contributes a reproducible, entropy-stable, and high-performance cryptographic mechanism that redefines the efficiency–security balance in modern encryption systems.

Circularly polarized luminescence (CPL) is of interest for optical encryption and anticounterfeiting applications. However, achieving dual-handed CPL emission from perovskite nanocrystals (PNCs) in hydrated chiral liquid crystal systems remains a challenge because of their susceptibility to water-induced degradation and disruption of liquid crystal ordering. These issues limit luminescence efficiency, structural integrity, and chiroptical control. Here, a confinement strategy is presented using polymer-encapsulated perovskite nanofibers, which isolate PNCs from water while supporting the in situ self-assembly of cellulose nanocrystals into a cholesteric photonic framework. The resulting solid-state composite achieves high photoluminescence quantum yield (65.56%), mechanical strength (32.15MPa), and a broad dissymmetry factor range (glum from -0.96 to +0.49) from a single left-handed cholesteric structure. Importantly, by engineering the reflectivity of asymmetric bilayer architectures, the composite exhibits enhanced dual-handed CPL emission depending on the viewing direction. The multimodal optical properties demonstrated here highlight the potential of this system in optical encryption and anticounterfeiting applications.

In this work, an encryption and decryption system utilizing physical unclonable function (PUF) characteristics of the Ta/WTiOx/Pt memristor array as hardware-level security primitive is demonstrated. PUF characteristics of the memristor are mainly attributed to the resistance variations, which are used as a physical unclonable entropy source with Hamming weight and inter Hamming distance close to 50%, showing high unpredictability in the application of a cryptographic key generator. Furthermore, combining international advanced encryption standard cryptographic algorithm and PUF-based keys, the encryption and decryption of 512 × 512-pixel Chinese Loong RGB image is successfully implemented by utilizing only 128 memristor arrays, which proves the lightweight and unclonable properties of the PUF-based security system. This work demonstrates that efficient image encryption and decryption can be accomplished by PUF characteristics of memristor arrays with high security and efficiency, proving its promising potential in constructing hardware–software cooperative security systems.

Quantum noise stream cipher (QNSC) is an encryption technique that leverages redundant information obscured by quantum noise to achieve an exponential increase in attack complexity, while continuous-variable quantum key distribution (CV-QKD) can provide such redundant information by generating secret keys. Notably, the optical architectures employed in these two schemes exhibit significant similarities. In this work, we employ polarization division multiplexing (PDM) to enhance channel capacity, enabling simultaneous transmission of signals under two different protocols over a single channel. To mitigate dynamic polarization state variations induced during signal propagation, we implement a polarization-interleaved subcarrier modulation (PISCM) scheme. We demonstrate that at a transmission distance of 20 km, the QKD secure key rate can be maintained at 4.93Mbps, while the QNSC transmission rate reaches 100Mbps. The expansion of the key rate from 4Mbps to 400Mbps using a linear feedback shift register (LFSR) enables synchronization with the 100Mbps QNSC signal, realizing a promising pathway toward an integrated communication and encryption system.

ABSTRACT The rapid expansion of digitalization has intensified cybersecurity risks, exposing critical network vulnerabilities despite significant advances in encryption and intrusion detection systems (IDS). Many existing deep learning–based IDS still struggle with high false‐positive rates, misclassification, and limited adaptability, reducing their effectiveness in real‐time defense scenarios. To address these limitations, this study proposes a Polymorphic Graph Gudermannian Neural Network integrated with Adaptive Chaotic Satin Bowerbird Optimization (PG‐GNN‐AC‐SBO), complemented by a lightweight encryption mechanism. The framework incorporates a Fuzzy K‐Top Matching Value (FKTMV) module for robust preprocessing and normalization, along with a Hybrid Cat Hunting Sea‐Horse Optimizer (H‐CHO‐SHO) for efficient and interpretable feature selection. The PG‐GNN classifier employs graph‐based learning and a Gudermannian nonlinear activation function to effectively capture complex traffic behavior, while AC‐SBO dynamically tunes hyperparameters to enhance stability and classification accuracy. To ensure data confidentiality, a Synchronously Scrambled Diffuse Encryption (SSDE) scheme is applied, delivering strong security with low computational overhead. Experimental evaluations on the NSL‐KDD and CICIDS2017 datasets demonstrate the superiority of the proposed approach, achieving up to 99.82% accuracy and outperforming state‐of‐the‐art methods. The encryption and decryption times of 3.50 and 3.55 ms further confirm the model's lightweight design. Overall, the proposed system provides high throughput with minimal latency, demonstrating strong potential for real‐time and large‐scale cybersecurity deployments.

Abstract This paper presents a terahertz (THz) metasurface with polarization-frequency multiplexing capability that uses vanadium dioxide (VO 2 ) to achieve dynamic wavefront control. The design leverages the phase transition of VO 2 to switch between reflective and transmissive operational modes. In the metallic state, the metasurface operates reflectively to form four channels under linear polarizations ( x -LP and y -LP) at 0.8 THz and 1.3 THz, generating diverse orbital angular momentum beams such as dual-, quadruple-, and octuple-vortex arrays. In the insulating state, it functions transmissively, creating two channels under x -LP and y -LP incidences at 0.8 THz via independent phase modulation, which produces multi-spot focal patterns like cross/X-shaped distributions and an eight-spot array. This work demonstrates full-space, six-channel (four reflective and two transmissive) wavefront manipulation, offering a viable strategy for developing high-performance devices for THz communication, imaging, and encryption systems.

As the core of a wireless interconnection system, optical communication plays a vital role in modern communication technology. The traditional photodetector (PD) is an important component of the receiving end, its photoresponse polarity is single, which cannot selectively identify the spectrum, and the complex and cumbersome configuration of the encryption system seriously restricts its further development. In this paper, we report a ZnO/organic polymer poly(N-vinylcarbazole) (PVK)/Cu2O/FTO heterojunction PD, which successfully achieves wavelength-dependent bipolar response output under zero bias by combining the bidirectional driving force of heterojunction and Schottky junction and reasonable band structure design. In the self-made simple optical communication system, 540 and 460 nm LED lamps that match the commercial RGB emission spectrum are used as the signal source, and the positive polarity valid signal is well hidden by the negative polarity key signal, to encrypt the information. By modulating the two signal sources, the ASCII code can be simplified to half of its original size, which has extraordinary significance for improving the data transmission speed. In addition, we have implemented the execution of multifunction optoelectronic logic gates (OLGs). This study provides a new idea for the design of bipolar response PDs and their application in emerging fields, such as visible light communication.

ABSTRACT Multimodal luminescent materials are pivotal for advanced anti‐counterfeiting and information encryption, but achieving multimodal luminescence in a single system remains challenging. Herein, all‐inorganic 0D lead‐free metal halide Cs 3 EuCl 6 nanocrystals (NCs) have been successfully synthesized, enabling the integration of four luminescent modes within one material. Under UV excitation, the NCs exhibit static photoluminescence (PL), while they show dynamic persistent luminescence (PersL) after the cessation of X‐ray irradiation. Moreover, the luminescent color depends on excitation wavelength and temperature. Remarkably, the NCs demonstrate reversible fluorescence responsiveness to water stimuli. The integration of four luminescent modes into a single, undoped material has not been reported so far, which benefits from the ladder‐like 4f energy levels of Eu 3+ ions and the highly confined 0D crystal structure of the NCs. Coupled with their excellent optical and thermal stability as well as water resistance, these properties enable the successful construction of sophisticated anti‐counterfeiting and dynamic information encryption systems. Furthermore, the temperature‐dependent luminescence showcases its great potential as an optical thermometer in the low temperature range (100–280 K). This work provides a novel paradigm for designing multimodal luminescent materials and opens promising avenues for complex information security applications.

Persistent luminescence materials typically encounter an intrinsic trade-off between high phosphorescence quantum yield (PhQY) and ultralong phosphorescence lifetime. To overcome this limitation, we propose a strategy that immobilizes silicon nanodots (SiNDs) within a dual-functional composite matrix. The SiNDs efficiently generate abundant triplet excitons through intersystem crossing processes and simultaneously exhibit high PhQYs. Importantly, the urea-paraformaldehyde-derived matrix provides both the spatial confinement of molten urea and the extensive hydrogen-bonding network of the urea-formaldehyde resin. This synergistic configuration effectively immobilizes triplet excitons and suppresses nonradiative decay pathways. As a result, the material exhibits a remarkable PhQY of 81.04% together with an ultralong afterglow lifetime of 3.44 s. Furthermore, the energy transfer strategy further extends the persistent afterglow into the deep-red region (702nm). Leveraging the tunable afterglow colors and time-resolved luminescent characteristics, an artificial intelligence-assisted information encryption system was successfully developed. This work demonstrates that integrating SiNDs with a dual-characteristic matrix provides a promising approach to concurrently achieving high PhQYs and ultralong lifetimes, thereby broadening the application scope of ultralong-afterglow materials and guiding the rational design of next-generation persistent luminescence materials.

Abstract Optical encryptions based on micro/nanophotonics attracts significant interest for its high security and capacity. Among promising device platforms, microcavity lasers offer distinct advantages for information labeling and encryption through unique lasing characteristics, such as spectral fingerprints. Image‐like outputs, including lasing modes and patterns, facilitate parallel multimodal information processing and are compatible with integrated schemes using optoelectronic sensors and processors, although it remains largely underexplored. In this work, an imaging‐based digital encryption platform is developed in principle using Fabry–Pérot (FP) microlaser arrays that are intra‐cavity‐integrated with custom‐designed micro‐optics. Microlenses (MLs) are designed and fabricated directly on a cavity mirror by two‐photon lithography (TPL), forming a ML‐integrated FP microcavity when paired with another mirror. By coordinating the microlens focal length with the cavity length, FP microlasers arrays are constructed with customizable high Q ‐factors, small mode volumes, and lasing thresholds. A spatially programmed microlens array (MLA), together with cavity length and pump energy, functions as a triple key for the optical multi‐attribute encryption system. Finally, a multi‐key authentication scheme based on micro Quick Response (QR) codes is demonstrated through lasing patterns of heterogeneous microlaser arrays. This work presents a digitalizable and scalable tools for all‐optical or optoelectronic anti‐counterfeiting and data encryption applications.

Secure communication has been required since thousands of years. This led to the invention of cryptography. In ancient world, primitive methods were adopted for passing messages secretly. But with the invention of internet and world wide web, which is used for communicating via mail, messages, online shopping, online banking, etc., increased the need of information security. Thus a proper understanding of various methods of cryptography and its implementation can fulfill the requirements of securing valuable and sensitive information. This paper takes us through the various methods of cryptography adopted in the ancient period, medieval period and the modern era. Ancient Egyptians and ancient Mesopotamians were the first to use basic encryption. The practice became more sophisticated in ancient Greece with philosophers like Polybios. Encryption dates back almost 4,000 years to the earliest uses of hieroglyphics. It has been used for everything from children's games to warfare in the intervening years and remains an important part of daily life today. In ancient Egypt, some hieroglyphs were substituted for others, possibly as a way to make texts more socially appropriate in various contexts. Other early ciphers included the ATBASH cipher and the Caesar cipher. Encryption is the process of putting information into a coded system and using a key to decipher it. It is different from encoding because a code can be reversed through the same mechanism that created it, whereas encryption requires a secret key. The basis of encryption is cryptography, the practice of writing and solving codes. There have historically been many uses for encryption, and there are uses today as well by anyone who wants to create secret information that can only be read by parties with the appropriate knowledge. It has applications in digital data security, warfare, games, mystery novels, and much more. The history of cryptography and the associated history of encryption is much longer than many people realize. It has increased in complexity over the years. Today, there are some forms of encryption that are effectively impossible to crack without the necessary information. People have long found good reasons to encrypt information to keep it away from prying eyes.