Jihene Malek - Academia.edu (original) (raw)

Papers by Jihene Malek

2012 International Conference on Computer Vision in Remote Sensing, 2012

ABSTRACT

Lightweight Cryptographic Techniques and Cybersecurity Approaches

Cryptography is the science that concerns protecting information by transforming its comprehensib... more Cryptography is the science that concerns protecting information by transforming its comprehensible form into an incomprehensible one. The conception of a robust cryptosystem is a challenge. In this paper, an improved hybrid cryptosystem for numerical image protection is presented. First, the initial secret key is generated by a secure hash function (keccak). Secondly, the plain image is encrypted through the advanced encryption standard (AES) with CTR mode. Finally, a Rivest-Shamir-Adleman (RSA) algorithm is used to secure the symmetric key transmitted over the insecure channel and owner signature. Our cryptosystem is implemented in hardware and evaluated by different tools mainly identified from the image cryptography community using numerous kinds of standard images. The experimental and analytical findings prove that our framework security gives a trade-off between robustness and performance, which can be used in several domains like medicine, military, and community privacy.

2022 IEEE 9th International Conference on Sciences of Electronics, Technologies of Information and Telecommunications (SETIT)

2021 18th International Multi-Conference on Systems, Signals & Devices (SSD)

With the growth of Computer Network and Communication Technology, medical images need to be excha... more With the growth of Computer Network and Communication Technology, medical images need to be exchanged safely by public communication networks. High security and high speed of image transmission become much more important. In this paper, an improved AES-ECC hybrid cryptosystem is proposed to be implemented in the DE2-115 board combining benefits of the Advanced Encryption Standard (AES) with CTR mode to accelerate data encryption and the Elliptic curve cryptography (ECC) to secure the exchange for symmetric session key. To reduce the execution time in the encryption process, both shift rows and mix columns operation in the AES are removed and replaced with a random permutation. Only six rounds of encryption are performed in a loop. In the ECC, both point addition and point doubling are optimized to use only two reused multipliers. Our hardware implementation on ALTERA CYCLONE IV.E FPGA, uses only 14% of logic elements achieving a maximum frequency of 236 MHz and consumed 1.35 mw of thermal power dissipation. Security analysis is successfully performed and our experiments prove that the suggested technique provides the basis of cryptography with more simplicity and correctness.

2019 IEEE International Conference on Design & Test of Integrated Micro & Nano-Systems (DTS), 2019

Today, image processing applications are frequently chosen in parallel with technological develop... more Today, image processing applications are frequently chosen in parallel with technological developments in areas such as security, health and traffic control. The most important criterion for used applications in these areas is to ensure that the system operates at high speed and in real time. Thereby, FPGAs are frequently used in such applications. An image processing algorithm is implemented in an FPGA-based development kit in this work. The ZedBoard Znyq-7000 development kit produced by Xilinx Company is used. The median filter as a nonlinear operator utilized for an oriented anisotropic diffusion function to reduce noise and preserve the edges, is performed on medical images. A pipelined architecture is proposed and developed. Experimental results show the filter efficiency in terms of processing time and image quality. The median filter runs at 81.1mus81.1 \mu s81.1mus for a human chest radiology of size 100times100100\times 100100times100 with a PSNR of 35.07 dB.

2018 15th International Multi-Conference on Systems, Signals & Devices (SSD), 2018

Anisotropic diffusion filter is very useful technique in image processing. This filtering method ... more Anisotropic diffusion filter is very useful technique in image processing. This filtering method has been shown to be effective in enhancing the visual quality of medical images and as preprocessing prior to advanced image processing. However, using standard software implementation, it is too hard to perform real-time anisotropic diffusion filtering due to its arithmetic complexity. To overcome this issue, hardware design is the ideal choice. This paper gives the algorithm and implementation of diffusion coefficient calculator on FPGA. The function has been successfully implemented and synthesised using the Xilinx ZYNQ-7 ZC702 FPGA. The platform shows that the diffusion coefficient calculator can operate at a maximum frequency of 210 MHz. The experimental results reveal a 143x and 5x performance improvement over the original c++ implementation and the GPU implementation by using NVIDIA Geforce 840M card, respectively.

International journal of imaging and robotics, 2016

The aim of this paper is reconstruction 2D of the human retina contour by fractal interpolation. ... more The aim of this paper is reconstruction 2D of the human retina contour by fractal interpolation. We start by segmenting the image to remove noise and then apply the active contour algorithm called Snake also to determine the contour of the blood vessel from the human retina image. Then, we used the Douglas-Peucker algorithm to determine the characteristic points of this contour. In the next step, the fractal interpolation is applied to reconstruct the contour. The results obtained show the effectiveness of the Douglas-Peucker algorithm is a simplification since the rate between 79% to 95%, and also the fractal interpolation advantage since it possible to reconstruct the curve with an error lower than 5%.

Journal of Real-Time Image Processing, 2021

In medical imaging, denoising is very important for the analysis of images and the diagnosis and ... more In medical imaging, denoising is very important for the analysis of images and the diagnosis and treatment of diseases. Currently, the image denoising methods based on anisotropic diffusion are efficient. However, the methods have been limited as regards the processing time. In recent computing systems, the FPGA-based acceleration has been highly competitive for GPU-based one due to its high computation capabilities and lower energy consumption. In this paper, we present a high-level synthesis implementation on a SOC-FPGA of an anisotropic diffusion algorithm dedicated to medical applications. We choose an oriented speckle reducing anisotropic diffusion denoising filter, which provides robust performance but requires a significant computation on the embedded CPU since it is iterative. Moreover, we optimize the performance by modifying the original algorithm, automizing it by controlling the diffusion process at each iteration, and accelerating the processing operations by providing a hardware/software description. The evaluation is performed using different medical images. The efficiency and relevance of the proposed filter is demonstrated through segmentation. The design is validated on FPGA XC7Z020CLG484-1 with a frequency of 255 MHz and a PSNR of about 30 dB.

2021 International Conference on Cyberworlds (CW), 2021

In telemedicine applications, sensitive and private patients' information is collected and tr... more In telemedicine applications, sensitive and private patients' information is collected and transmitted via a telecommunication system. To assure the security services of the exchanged medical images, improved cryptographic algorithms should be designed to protect private information against attacks. In this paper, we propose an efficient cryptosystem for medical image encryption and authentication. The cryptosystem is an Improved Advanced Encryption Standard (IAES) - Elliptic Curve Digital Signature Algorithm (ECDSA) hybrid scheme that uses symmetric and asymmetric approaches. The first one is used to encrypting the image. The second one is used to encrypting the initial secret key and owner's signature that permit authentication. The implementation on a Cyclone III FPGA uses 18.594 of total logic elements, 17.820 of total combinatorial functions, and 131.616 of total memory. It runs at a frequency of 147.16 MHz, consumes 171.16 mW and can achieve excellent throughput of 1.71 Gb / s. Results prove that the proposed cipher framework is appropriate for embedded systems respecting both real-time performance and resources constrained. The security analysis is successfully performed and experimental results prove that the suggested technique provides the basis of cryptography.

Multimedia Tools and Applications, 2021

Currently, embedded systems can be found everywhere in quotidian life. In the development of embe... more Currently, embedded systems can be found everywhere in quotidian life. In the development of embedded systems, information security is one of the important factors. Encryption is an efficient technique to protect information against attacks. However, because of constraints, existing encryption functions are not compatible and do not agree with real-time applications in embedded systems. In this paper, an improved cryptographic approach with a high level of security and high speed is put forward. Our work uses an efficient version of a hybrid scheme comprising an Advanced Encryption Standard (AES) - Elliptic Curve Cryptography (ECC) for medical image encryption, which combines the benefits of the symmetric AES to speed-up data encryption and asymmetric ECC in order to secure the interchange of a symmetric session key. The contribution of this paper consists of the following two main points: First, we put forward an optimized ECC hardware architecture to respect the compromise between area, power dissipation, and speed. Thus, we primarily utilize only two multipliers to develop the Point Addition (PA) block and the Point Doubling (PD) block, which reduces time complexity. Then, a 32-bit multiplier and a 32-bit inverter architecture based on shifts and XORs are proposed to reduce power consumption and area occupancy. Second, for image encryption, we primarily propose to modify the AES by eliminating the mix-columns transformation and replacing it with a permutation based on the shifts of columns, which decreases time complexity while maintaining the Shannon diffusion and the confusion principle. Then, an adjustment of the rearrangement of the general structure is given to enhance the entropy value. The global cryptosystem is implemented using a co-design approach where the modified AES runs on the NIOS II processor, and the scalar ECC multiplication is designed as a hardware accelerator. The suggested cryptographic system spends much less execution time, which is a significant factor for being applied in practice. Security analysis is successfully performed, and our experiments prove that our proposed technique provides the basics of cryptography with more simplicity and correctness. In fact, the results of the evaluation prove the effectiveness, rapidity and high security of the suggested algorithm.

Journal of Ambient Intelligence and Humanized Computing, 2021

Multimedia Tools and Applications, 2021

Real-time multimedia applications are increasingly achieving success in the everyday world. There... more Real-time multimedia applications are increasingly achieving success in the everyday world. Thereby, multimedia information relies on security to protect private life. The Advanced Encryption Standard (AES) has been designed to secure different applications. Yet, some limitations are given, making it inappropriate for secure video storation and transmission. The limitations are the time complexity, the multiple iterations, and the predefined substitution box. Thus, any user can use it to break the encryption. Moreover, the multiple iterations augment the need for CPU usage, and so the overall run time. Hence, it is necessary to modify the AES algorithm to make it more appropriate for securing video frames transmission over insecure channel. In this paper, an Improved AES (IAES) is put forward, which improves both diffusion and confusion in ciphered video. Our work consists in the following two main points: First, we propose to eliminate both shift-row and sub-byte transformations and replace them with a mix-row operation. This task reduces the run time, which presents a significant factor for real-time video transmission. Equally important, we propose to use the henon chaotic map in the key generation procedure, which provides more randomness. The Hash Algorithm SHA-3 is used to generate the initial conditions of the chaotic attractor. The video encryption procedure is verified with success, and the experimental results confirm that the novel algorithm combining chaos and IAES augments the entropy of the ciphered video by 15% and reduces the complexity time for both encryption and decryption compared to the standard one. Security analysis is successfully performed, and the results prove that our suggested technique provides the basics of cryptography with more correctness. The PRNG is tested by NIST 800–22 test suit, which indicates that it is suitable for secure image encryption. It provides a large key space of 2 128 which resists the brute-force attack. All in all, the findings confirm that the novel security approach eliminates the limitation of the existing AES and provides a trade-off between speed and safety levels to secure video transmission.

Journal of Circuits, Systems and Computers, 2021

This paper proposes a well-optimized FPGA implementation of a chaos-based cryptosystem for real-t... more This paper proposes a well-optimized FPGA implementation of a chaos-based cryptosystem for real-time image encryption and decryption. A highly sensitive Pseudo-Random Number Generator (PRNG) based on the Lorenz chaotic system is designed to generate pseudo-random numbers. A high-quality encryption key is acquired by encrypting the numbers of a 128-bit counter using the PRNG. For image encryption, the image is first decomposed into 128-bit blocks. Then, the blocks are encrypted by XORing pixels with the key stream. [Formula: see text] cycles of encryption can be achieved to increase complexity. Finally, the blocks are concatenated to form an encrypted image. The algorithm is designed, implemented, and validated on the Xilinx Zynq FPGA platform using the Vivado/System Generator tool. The hardware design is well optimized for pipeline processing and low resource utilization. The experimental synthesis indicates that the provided architecture achieves high performance in terms of freque...

Smart Innovation, Systems and Technologies, 2019

In this paper, we propose a cryptography system for digital image high securing. Our method is as... more In this paper, we propose a cryptography system for digital image high securing. Our method is asymmetric utilizing RSA algorithm, which requires a public key for encryption and a private key for decryption. However, the image is encrypted with a combination between the AES-256 CTR mode algorithm and the SHA-2 function. Our algorithm is evaluated by several tools and tests mainly selected from the image cryptography community using many types of standard non compressed images. The experimental and analytical results demonstrate that our encryption scheme provides a high robustness and security. It can resist the most known cryptanalysis attacks. Very good results are obtained, which allows us to confirm the high performance and efficiency of our algorithm for image high protection, which can be used in several domains like military and community privacy.

Scientific Programming, 2021

Securing medical images is a great challenge to protect medical privacy. An image encryption mode... more Securing medical images is a great challenge to protect medical privacy. An image encryption model founded on a complex chaos-based Pseudorandom Number Generator (PRNG) and Modified Advanced Encryption Standard (MAES) is put forward in this paper. Our work consists of the following three main points. First, we propose the use of a complex PRNG based on two different chaotic systems which are the 2D Logistic map in a complex set and Henon’s system in the key generation procedure. Second, in the MAES 128 bits, the subbytes’ operation is performed using four different S-boxes for more complexity. Third, both shift-rows’ and mix-columns’ transformations are eliminated and replaced with a random permutation method which increases the complexity. More importantly, only four rounds of encryption are performed in a loop that reduces significantly the execution time. The overall system is implemented on the Altera Cyclone III board, which is completed with an SD card interface for medical im...

Scientific Programming, 2020

In the medical sector, the digital image is multimedia data that contain secret information. Howe... more In the medical sector, the digital image is multimedia data that contain secret information. However, designing an efficient secure cryptosystem to protect the confidential images in sharing is a challenge. In this work, we propose an improved chaos-based cryptosystem to encrypt and decrypt rapidly secret medical images. A complex chaos-based PRNG is suggested to generate a high-quality key that presents high randomness behaviour, high entropy, and high complexity. An improved architecture is proposed to encrypt the secret image that is based on permutation, substitution, and diffusion properties. In the first step, the image’s pixels are randomly permuted through a matrix generated using the PRNG. Next, pixel’s bits are permuted using an internal condition. After that, the pixels are substituted using two different S-boxes with an internal condition. In the final step, the image is diffused by XORing pixels with the key stream generated by the PRNG in order to acquire an encrypted ...

International Journal of Information and Computer Security, 2020

International Journal of Mobile Learning and Organisation, 2019

A significant interest and a considerable attention have been given, in recent years, to the mobi... more A significant interest and a considerable attention have been given, in recent years, to the mobile pervasive and the Internet of Things (IoT) throughout different fields such as education. However, there are only few empirical examples regarding the use of those technologies in learning design and there is a scarcity of theoretical researches and studies within the literature. This paper seeks to fill this gap by investigating features required in designing such TEL scenarios and by proposing a methodology that allows teachers to design, simulate, enact and track, innovative learning scenarios. The strengths of our approach lie in the fact that it takes into account both design and runtime phases by combining mobile and IoT Key elements, Model-driven development, Activity theory and Tin-Can Api specification. We have conducted two researches at the Tunisian Bardo National Museum to verify the utility of applying the proposed methodology. The paper concludes with a discussion of how the methodology meets the challenges.

Neural Computing and Applications, 2017

Recently, numerous research works in retinalstructure analysis have been performed to analyze ret... more Recently, numerous research works in retinalstructure analysis have been performed to analyze retinal images for diagnosing and preventing ocular diseases such as diabetic retinopathy, which is the first most common causes of vision loss in the world. In this paper, an algorithm for vessel detection in fundus images is employed. First, a denoising process using the noise-estimation-based anisotropic diffusion technique is applied to restore connected vessel lines in a retinal image and eliminate noisy lines. Next, a multi-scale line-tracking algorithm is implemented to detect all the blood vessels having similar dimensions at a selected scale. An openly available dataset, called ''the STARE Project's dataset,'' has been firstly utilized to evaluate the accuracy of the proposed method. Accordingly, our experimental results, performed on the STARE dataset, depict a maximum average accuracy of around 93.88%. Then, an experimental evaluation on another dataset, named DRIVE database, demonstrates a satisfactory performance of the proposed technique, where the maximum average accuracy rate of 93.89% is achieved.

International Journal of Modelling, Identification and Control, 2016

The retina's high oxygen demands and the retinal vasculature's relatively sparse nature are assum... more The retina's high oxygen demands and the retinal vasculature's relatively sparse nature are assumed to contribute to the retina's specific vulnerability to vascular diseases. This study has been designed to model the oxygen transport in physiologically realistic retinal networks. A computational fluid dynamics study has been conducted to investigate the effect of topological changes on the oxygen partial pressure distribution in retinal blood vessels. The Navier Stokes equations for blood flow and the mass transport equation for oxygen have been coupled and solved simultaneously for the laminar flow mass transfer problem. The mean oxygen saturation of a healthy eye has been 93% in retinal arterioles and 58% in venules. The arteriovenous difference has been 35%. For a patient with a central retinal vein occlusion (CRVO), the mean oxygen saturation has been 33%. The findings from the analysis are generally consistent with a lot of previous experimental measurements and clinical data available in the literature, demonstrating the efficiency of our model for predicting the oxygen distribution in the retinal networks. This paves the way for a new research and applications for simulating inaccessible cases from experimental studies.

2012 International Conference on Computer Vision in Remote Sensing, 2012

ABSTRACT

Lightweight Cryptographic Techniques and Cybersecurity Approaches

Cryptography is the science that concerns protecting information by transforming its comprehensib... more Cryptography is the science that concerns protecting information by transforming its comprehensible form into an incomprehensible one. The conception of a robust cryptosystem is a challenge. In this paper, an improved hybrid cryptosystem for numerical image protection is presented. First, the initial secret key is generated by a secure hash function (keccak). Secondly, the plain image is encrypted through the advanced encryption standard (AES) with CTR mode. Finally, a Rivest-Shamir-Adleman (RSA) algorithm is used to secure the symmetric key transmitted over the insecure channel and owner signature. Our cryptosystem is implemented in hardware and evaluated by different tools mainly identified from the image cryptography community using numerous kinds of standard images. The experimental and analytical findings prove that our framework security gives a trade-off between robustness and performance, which can be used in several domains like medicine, military, and community privacy.

2022 IEEE 9th International Conference on Sciences of Electronics, Technologies of Information and Telecommunications (SETIT)

2021 18th International Multi-Conference on Systems, Signals & Devices (SSD)

With the growth of Computer Network and Communication Technology, medical images need to be excha... more With the growth of Computer Network and Communication Technology, medical images need to be exchanged safely by public communication networks. High security and high speed of image transmission become much more important. In this paper, an improved AES-ECC hybrid cryptosystem is proposed to be implemented in the DE2-115 board combining benefits of the Advanced Encryption Standard (AES) with CTR mode to accelerate data encryption and the Elliptic curve cryptography (ECC) to secure the exchange for symmetric session key. To reduce the execution time in the encryption process, both shift rows and mix columns operation in the AES are removed and replaced with a random permutation. Only six rounds of encryption are performed in a loop. In the ECC, both point addition and point doubling are optimized to use only two reused multipliers. Our hardware implementation on ALTERA CYCLONE IV.E FPGA, uses only 14% of logic elements achieving a maximum frequency of 236 MHz and consumed 1.35 mw of thermal power dissipation. Security analysis is successfully performed and our experiments prove that the suggested technique provides the basis of cryptography with more simplicity and correctness.

2019 IEEE International Conference on Design & Test of Integrated Micro & Nano-Systems (DTS), 2019

Today, image processing applications are frequently chosen in parallel with technological develop... more Today, image processing applications are frequently chosen in parallel with technological developments in areas such as security, health and traffic control. The most important criterion for used applications in these areas is to ensure that the system operates at high speed and in real time. Thereby, FPGAs are frequently used in such applications. An image processing algorithm is implemented in an FPGA-based development kit in this work. The ZedBoard Znyq-7000 development kit produced by Xilinx Company is used. The median filter as a nonlinear operator utilized for an oriented anisotropic diffusion function to reduce noise and preserve the edges, is performed on medical images. A pipelined architecture is proposed and developed. Experimental results show the filter efficiency in terms of processing time and image quality. The median filter runs at 81.1mus81.1 \mu s81.1mus for a human chest radiology of size 100times100100\times 100100times100 with a PSNR of 35.07 dB.

2018 15th International Multi-Conference on Systems, Signals & Devices (SSD), 2018

Anisotropic diffusion filter is very useful technique in image processing. This filtering method ... more Anisotropic diffusion filter is very useful technique in image processing. This filtering method has been shown to be effective in enhancing the visual quality of medical images and as preprocessing prior to advanced image processing. However, using standard software implementation, it is too hard to perform real-time anisotropic diffusion filtering due to its arithmetic complexity. To overcome this issue, hardware design is the ideal choice. This paper gives the algorithm and implementation of diffusion coefficient calculator on FPGA. The function has been successfully implemented and synthesised using the Xilinx ZYNQ-7 ZC702 FPGA. The platform shows that the diffusion coefficient calculator can operate at a maximum frequency of 210 MHz. The experimental results reveal a 143x and 5x performance improvement over the original c++ implementation and the GPU implementation by using NVIDIA Geforce 840M card, respectively.

International journal of imaging and robotics, 2016

The aim of this paper is reconstruction 2D of the human retina contour by fractal interpolation. ... more The aim of this paper is reconstruction 2D of the human retina contour by fractal interpolation. We start by segmenting the image to remove noise and then apply the active contour algorithm called Snake also to determine the contour of the blood vessel from the human retina image. Then, we used the Douglas-Peucker algorithm to determine the characteristic points of this contour. In the next step, the fractal interpolation is applied to reconstruct the contour. The results obtained show the effectiveness of the Douglas-Peucker algorithm is a simplification since the rate between 79% to 95%, and also the fractal interpolation advantage since it possible to reconstruct the curve with an error lower than 5%.

Journal of Real-Time Image Processing, 2021

In medical imaging, denoising is very important for the analysis of images and the diagnosis and ... more In medical imaging, denoising is very important for the analysis of images and the diagnosis and treatment of diseases. Currently, the image denoising methods based on anisotropic diffusion are efficient. However, the methods have been limited as regards the processing time. In recent computing systems, the FPGA-based acceleration has been highly competitive for GPU-based one due to its high computation capabilities and lower energy consumption. In this paper, we present a high-level synthesis implementation on a SOC-FPGA of an anisotropic diffusion algorithm dedicated to medical applications. We choose an oriented speckle reducing anisotropic diffusion denoising filter, which provides robust performance but requires a significant computation on the embedded CPU since it is iterative. Moreover, we optimize the performance by modifying the original algorithm, automizing it by controlling the diffusion process at each iteration, and accelerating the processing operations by providing a hardware/software description. The evaluation is performed using different medical images. The efficiency and relevance of the proposed filter is demonstrated through segmentation. The design is validated on FPGA XC7Z020CLG484-1 with a frequency of 255 MHz and a PSNR of about 30 dB.

2021 International Conference on Cyberworlds (CW), 2021

In telemedicine applications, sensitive and private patients' information is collected and tr... more In telemedicine applications, sensitive and private patients' information is collected and transmitted via a telecommunication system. To assure the security services of the exchanged medical images, improved cryptographic algorithms should be designed to protect private information against attacks. In this paper, we propose an efficient cryptosystem for medical image encryption and authentication. The cryptosystem is an Improved Advanced Encryption Standard (IAES) - Elliptic Curve Digital Signature Algorithm (ECDSA) hybrid scheme that uses symmetric and asymmetric approaches. The first one is used to encrypting the image. The second one is used to encrypting the initial secret key and owner's signature that permit authentication. The implementation on a Cyclone III FPGA uses 18.594 of total logic elements, 17.820 of total combinatorial functions, and 131.616 of total memory. It runs at a frequency of 147.16 MHz, consumes 171.16 mW and can achieve excellent throughput of 1.71 Gb / s. Results prove that the proposed cipher framework is appropriate for embedded systems respecting both real-time performance and resources constrained. The security analysis is successfully performed and experimental results prove that the suggested technique provides the basis of cryptography.

Multimedia Tools and Applications, 2021

Currently, embedded systems can be found everywhere in quotidian life. In the development of embe... more Currently, embedded systems can be found everywhere in quotidian life. In the development of embedded systems, information security is one of the important factors. Encryption is an efficient technique to protect information against attacks. However, because of constraints, existing encryption functions are not compatible and do not agree with real-time applications in embedded systems. In this paper, an improved cryptographic approach with a high level of security and high speed is put forward. Our work uses an efficient version of a hybrid scheme comprising an Advanced Encryption Standard (AES) - Elliptic Curve Cryptography (ECC) for medical image encryption, which combines the benefits of the symmetric AES to speed-up data encryption and asymmetric ECC in order to secure the interchange of a symmetric session key. The contribution of this paper consists of the following two main points: First, we put forward an optimized ECC hardware architecture to respect the compromise between area, power dissipation, and speed. Thus, we primarily utilize only two multipliers to develop the Point Addition (PA) block and the Point Doubling (PD) block, which reduces time complexity. Then, a 32-bit multiplier and a 32-bit inverter architecture based on shifts and XORs are proposed to reduce power consumption and area occupancy. Second, for image encryption, we primarily propose to modify the AES by eliminating the mix-columns transformation and replacing it with a permutation based on the shifts of columns, which decreases time complexity while maintaining the Shannon diffusion and the confusion principle. Then, an adjustment of the rearrangement of the general structure is given to enhance the entropy value. The global cryptosystem is implemented using a co-design approach where the modified AES runs on the NIOS II processor, and the scalar ECC multiplication is designed as a hardware accelerator. The suggested cryptographic system spends much less execution time, which is a significant factor for being applied in practice. Security analysis is successfully performed, and our experiments prove that our proposed technique provides the basics of cryptography with more simplicity and correctness. In fact, the results of the evaluation prove the effectiveness, rapidity and high security of the suggested algorithm.

Journal of Ambient Intelligence and Humanized Computing, 2021

Multimedia Tools and Applications, 2021

Real-time multimedia applications are increasingly achieving success in the everyday world. There... more Real-time multimedia applications are increasingly achieving success in the everyday world. Thereby, multimedia information relies on security to protect private life. The Advanced Encryption Standard (AES) has been designed to secure different applications. Yet, some limitations are given, making it inappropriate for secure video storation and transmission. The limitations are the time complexity, the multiple iterations, and the predefined substitution box. Thus, any user can use it to break the encryption. Moreover, the multiple iterations augment the need for CPU usage, and so the overall run time. Hence, it is necessary to modify the AES algorithm to make it more appropriate for securing video frames transmission over insecure channel. In this paper, an Improved AES (IAES) is put forward, which improves both diffusion and confusion in ciphered video. Our work consists in the following two main points: First, we propose to eliminate both shift-row and sub-byte transformations and replace them with a mix-row operation. This task reduces the run time, which presents a significant factor for real-time video transmission. Equally important, we propose to use the henon chaotic map in the key generation procedure, which provides more randomness. The Hash Algorithm SHA-3 is used to generate the initial conditions of the chaotic attractor. The video encryption procedure is verified with success, and the experimental results confirm that the novel algorithm combining chaos and IAES augments the entropy of the ciphered video by 15% and reduces the complexity time for both encryption and decryption compared to the standard one. Security analysis is successfully performed, and the results prove that our suggested technique provides the basics of cryptography with more correctness. The PRNG is tested by NIST 800–22 test suit, which indicates that it is suitable for secure image encryption. It provides a large key space of 2 128 which resists the brute-force attack. All in all, the findings confirm that the novel security approach eliminates the limitation of the existing AES and provides a trade-off between speed and safety levels to secure video transmission.

Journal of Circuits, Systems and Computers, 2021

This paper proposes a well-optimized FPGA implementation of a chaos-based cryptosystem for real-t... more This paper proposes a well-optimized FPGA implementation of a chaos-based cryptosystem for real-time image encryption and decryption. A highly sensitive Pseudo-Random Number Generator (PRNG) based on the Lorenz chaotic system is designed to generate pseudo-random numbers. A high-quality encryption key is acquired by encrypting the numbers of a 128-bit counter using the PRNG. For image encryption, the image is first decomposed into 128-bit blocks. Then, the blocks are encrypted by XORing pixels with the key stream. [Formula: see text] cycles of encryption can be achieved to increase complexity. Finally, the blocks are concatenated to form an encrypted image. The algorithm is designed, implemented, and validated on the Xilinx Zynq FPGA platform using the Vivado/System Generator tool. The hardware design is well optimized for pipeline processing and low resource utilization. The experimental synthesis indicates that the provided architecture achieves high performance in terms of freque...

Smart Innovation, Systems and Technologies, 2019

In this paper, we propose a cryptography system for digital image high securing. Our method is as... more In this paper, we propose a cryptography system for digital image high securing. Our method is asymmetric utilizing RSA algorithm, which requires a public key for encryption and a private key for decryption. However, the image is encrypted with a combination between the AES-256 CTR mode algorithm and the SHA-2 function. Our algorithm is evaluated by several tools and tests mainly selected from the image cryptography community using many types of standard non compressed images. The experimental and analytical results demonstrate that our encryption scheme provides a high robustness and security. It can resist the most known cryptanalysis attacks. Very good results are obtained, which allows us to confirm the high performance and efficiency of our algorithm for image high protection, which can be used in several domains like military and community privacy.

Scientific Programming, 2021

Securing medical images is a great challenge to protect medical privacy. An image encryption mode... more Securing medical images is a great challenge to protect medical privacy. An image encryption model founded on a complex chaos-based Pseudorandom Number Generator (PRNG) and Modified Advanced Encryption Standard (MAES) is put forward in this paper. Our work consists of the following three main points. First, we propose the use of a complex PRNG based on two different chaotic systems which are the 2D Logistic map in a complex set and Henon’s system in the key generation procedure. Second, in the MAES 128 bits, the subbytes’ operation is performed using four different S-boxes for more complexity. Third, both shift-rows’ and mix-columns’ transformations are eliminated and replaced with a random permutation method which increases the complexity. More importantly, only four rounds of encryption are performed in a loop that reduces significantly the execution time. The overall system is implemented on the Altera Cyclone III board, which is completed with an SD card interface for medical im...

Scientific Programming, 2020

In the medical sector, the digital image is multimedia data that contain secret information. Howe... more In the medical sector, the digital image is multimedia data that contain secret information. However, designing an efficient secure cryptosystem to protect the confidential images in sharing is a challenge. In this work, we propose an improved chaos-based cryptosystem to encrypt and decrypt rapidly secret medical images. A complex chaos-based PRNG is suggested to generate a high-quality key that presents high randomness behaviour, high entropy, and high complexity. An improved architecture is proposed to encrypt the secret image that is based on permutation, substitution, and diffusion properties. In the first step, the image’s pixels are randomly permuted through a matrix generated using the PRNG. Next, pixel’s bits are permuted using an internal condition. After that, the pixels are substituted using two different S-boxes with an internal condition. In the final step, the image is diffused by XORing pixels with the key stream generated by the PRNG in order to acquire an encrypted ...

International Journal of Information and Computer Security, 2020

International Journal of Mobile Learning and Organisation, 2019

A significant interest and a considerable attention have been given, in recent years, to the mobi... more A significant interest and a considerable attention have been given, in recent years, to the mobile pervasive and the Internet of Things (IoT) throughout different fields such as education. However, there are only few empirical examples regarding the use of those technologies in learning design and there is a scarcity of theoretical researches and studies within the literature. This paper seeks to fill this gap by investigating features required in designing such TEL scenarios and by proposing a methodology that allows teachers to design, simulate, enact and track, innovative learning scenarios. The strengths of our approach lie in the fact that it takes into account both design and runtime phases by combining mobile and IoT Key elements, Model-driven development, Activity theory and Tin-Can Api specification. We have conducted two researches at the Tunisian Bardo National Museum to verify the utility of applying the proposed methodology. The paper concludes with a discussion of how the methodology meets the challenges.

Neural Computing and Applications, 2017

Recently, numerous research works in retinalstructure analysis have been performed to analyze ret... more Recently, numerous research works in retinalstructure analysis have been performed to analyze retinal images for diagnosing and preventing ocular diseases such as diabetic retinopathy, which is the first most common causes of vision loss in the world. In this paper, an algorithm for vessel detection in fundus images is employed. First, a denoising process using the noise-estimation-based anisotropic diffusion technique is applied to restore connected vessel lines in a retinal image and eliminate noisy lines. Next, a multi-scale line-tracking algorithm is implemented to detect all the blood vessels having similar dimensions at a selected scale. An openly available dataset, called ''the STARE Project's dataset,'' has been firstly utilized to evaluate the accuracy of the proposed method. Accordingly, our experimental results, performed on the STARE dataset, depict a maximum average accuracy of around 93.88%. Then, an experimental evaluation on another dataset, named DRIVE database, demonstrates a satisfactory performance of the proposed technique, where the maximum average accuracy rate of 93.89% is achieved.

International Journal of Modelling, Identification and Control, 2016

The retina's high oxygen demands and the retinal vasculature's relatively sparse nature are assum... more The retina's high oxygen demands and the retinal vasculature's relatively sparse nature are assumed to contribute to the retina's specific vulnerability to vascular diseases. This study has been designed to model the oxygen transport in physiologically realistic retinal networks. A computational fluid dynamics study has been conducted to investigate the effect of topological changes on the oxygen partial pressure distribution in retinal blood vessels. The Navier Stokes equations for blood flow and the mass transport equation for oxygen have been coupled and solved simultaneously for the laminar flow mass transfer problem. The mean oxygen saturation of a healthy eye has been 93% in retinal arterioles and 58% in venules. The arteriovenous difference has been 35%. For a patient with a central retinal vein occlusion (CRVO), the mean oxygen saturation has been 33%. The findings from the analysis are generally consistent with a lot of previous experimental measurements and clinical data available in the literature, demonstrating the efficiency of our model for predicting the oxygen distribution in the retinal networks. This paves the way for a new research and applications for simulating inaccessible cases from experimental studies.