Links Assignment Scheme based on Potential Edges Importance in Dual-layer Wavelength Routing Optical Satellite Networks

With the development of the massive satellite constellation and the on-orbit laser-based communication equipment, the wavelength routing optical satellite network (WROSN) becomes a potential solution for on-orbit, high-capacity, and high-speed communication. Since the inter-satellite links (ISLs) are time-varying, one of the fundamental considerations in the construction of the WROSN is assigning limited laser communication terminals for each satellite to establish ISLs with the visible satellites. Therefore, we propose a links assignment scheme (LAS) based on the potential edges importance matrix (PEIM) algorithm to construct a temporarily stable topology of the ISLs for a dual-layer constellation. The simulation results showed that the LAS based on the PEIM algorithm is better than LAS based on the random or Greedy algorithm in terms of node-to-node distance, node pair connectivity, wavelength demand, and transmission delay. The node pair connectivity and wavelength demand in WROSN is a trade-off problem. The research in this paper also brings a novel method for reduction of the cost of the on-board resources, that is through designing topology of the ISLs with links assignment algorithm.Comment: This is the manuscript version that was submitted to the International Journal of Satellite Communications and Networking (SAT-23-0018

Key Distribution and Changing Key Cryptosystem Based on Phase Retrieval Algorithm and RSA Public-Key Algorithm

The optical image encryption has attracted more and more researchers’ attention, and the various encryption schemes have been proposed. In existing optical cryptosystem, the phase functions or images are usually used as the encryption keys, and it is difficult that the traditional public-key algorithm (such as RSA, ECC, etc.) is used to complete large numerical key transfer. In this paper, we propose a key distribution scheme based on the phase retrieval algorithm and the RSA public-key algorithm, which solves the problem for the key distribution in optical image encryption system. Furthermore, we also propose a novel image encryption system based on the key distribution principle. In the system, the different keys can be used in every encryption process, which greatly improves the security of the system

The Weighted Fractional Fourier Transform and Its Application in Image Encryption

With the rapid development of information, the requirements for the security and reliability of cryptosystems have become increasingly difficult to meet, which promotes the development of the theory of a class of fractional Fourier transforms. In this paper, we present a review of the development and applications of the weighted fractional Fourier transform (WFRFT) in image encryption. Relationships between the algorithms are established using the generalized permutation matrix group in theoretical analysis. In addition, the advantages and potential weaknesses of each algorithm in image encryption are analyzed and discussed. It is expected that this review will provide a clear picture of the current developments of the WFRFT in image encryption and may shed some light on future developments

Fabrication of gallic acid electrochemical sensor based on interconnected Super-P carbon black@mesoporous silica nanocomposite modified glassy carbon electrode

The efficient and accurate detection of gallic acid (GA) is particularly important for human health. Herein, a simple and low-cost ultrasonic-assisted strategy was proposed for the preparation of multifunctional nanocomposite of Super-P carbon black (SPCB) nanoparticles and mesoporous silica nanoparticles (MSNs), which was used to modify the glassy carbon electrode (GCE) for the fabrication of GA electrochemical sensor (SPCB@MSNs/GCE). SPCB with pearl-chain nanostructure presented an interconnected highly conductive carbon network, which significantly improved the charge transfer efficiency. MSNs with spherical morphology and mesoporous structure exhibited uniform particle dispersion and high active surface area, which remarkably improved the surface accumulation effect of sensing electrode towards GA. Moreover, the excellent electrical conductivity of SPCB compensated for the non-conductive property of MSNs. Under the optimized condition, the electrochemical response of SPCB@MSNs/GCE sensor had a good linear relationship with GA concentration (0.5–10 μM), and the corresponding limit of detection could reach up to 4.911 nM. The fabricated nanohybrid sensor showed good reproducibility, repeatability and anti-interference property. Moreover, the satisfactory GA recoveries and RSD values were achieved for the electrochemical detection of GA in tea samples. This work provides an important reference for the highly sensitive analysis of GA in the field of food safety