Variable - weight optical code division multiple access system using different detection schemes

In this paper a Variable Weight OCDMA (VWOCDMA) system using KS code with Direct Decoding (DD), Complementary Subtraction (CS) and AND subtraction detections is proposed. System performance is analyzed using mathematical approximation and software simulation. In mathematical analysis, the effects of Phase-Induced Intensity Noise, shot noise and thermal noise are taken into account. Bit Error Rate of different users is plotted as a function of received optical power per chip with varying the bit rates and number of active users. It has been shown that for different bit rates and number of users, system using DD has better performance than the system applying CS and AND detection. Using DD scheme, the number of active users are 100 while this value is 27 and 25 in case of using CS and AND detection, respectively, when the received optical power per chip is –10 dBm

A Lightweight Chaos-Based Medical Image Encryption Scheme Using Random Shuffling and XOR Operations

Medical images possess significant importance in diagnostics when it comes to healthcare systems. These images contain confidential and sensitive information such as patients’ X-rays, ultrasounds, computed tomography scans, brain images, and magnetic resonance imaging. However, the low security of communication channels and the loopholes in storage systems of hospitals or medical centres put these images at risk of being accessed by unauthorized users who illegally exploit them for non-diagnostic purposes. In addition to improving the security of communication channels and storage systems, image encryption is a popular strategy adopted to ensure the safety of medical images against unauthorized access. In this work, we propose a lightweight cryptosystem based on Henon chaotic map, Brownian motion, and Chen’s chaotic system to encrypt medical images with elevated security. The efficiency of the proposed system is proved in terms of histogram analysis, adjacent pixels correlation analysis, contrast analysis, homogeneity analysis, energy analysis, NIST analysis, mean square error, information entropy, number of pixels changing rate, unified average changing intensity, peak to signal noise ratio and time complexity. The experimental results show that the proposed cryptosystem is a lightweight approach that can achieve the desired security level for encrypting confidential image-based patients’ information

Variable-Weight Optical Code Division Multiple Access System using Different Detection Schemes

In this paper a Variable Weight OCDMA (VW-OCDMA) system using KS code with Direct Decoding (DD), Complementary Subtraction (CS) and AND subtraction detections is proposed. System performance is analyzed using mathematical approximation and software simulation. In mathematical analysis, the eects of Phase-Induced Intensity Noise, shot noise and thermal noise are taken into account. Bit Error Rate of dierent users is plotted as a function of received optical power per chip with varying the bit rates and number of active users. It has been shown that for dierent bit rates and number of users, system using DD has better performance than the system applying CS and AND detection. Using DD scheme, the number of active users are 100 while this value is 27 and 25 in case of using CS and AND detection, respectively, when the received optical power per chip is -10 dBm

Securing Medical Images for Mobile Health Systems Using a Combined Approach of Encryption and Steganography

© 2018, Springer International Publishing AG, part of Springer Nature. In this paper, we propose a medical image encryption scheme which can be used in mobile health systems. The proposed scheme combines RSA algorithm, logistic chaotic encryption algorithm, and steganography technique to secure medical images. In the proposed scheme, we encrypt a medical image based on chaotic sequence and encrypt the initial value of the chaotic sequence using the RSA encryption algorithm. The encrypted information by RSA is hidden in the Image. Only legitimate users can obtain the parameter information and restore the image. In the receiver side, we apply the inverse methods to get the original image after an encrypted image is arrived. We have implemented a simple application on the Android platform and have evaluated its performance. The experimental results show that the proposed image encryption scheme is practical and feasible for mobile health systems