Rhouma Rhouma | Ecole Nationale d'Ingénieurs de Tunis (ENIT) (original) (raw)
Papers by Rhouma Rhouma
Chaos: An Interdisciplinary Journal of Nonlinear Science, 2008
This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the... more This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the logistic map. Some problems are emphasized concerning the key space definition and the implementation of the cryptosystem using floating-point operations. It is also shown how it is possible to reduce considerably the key space through a ciphertext-only attack. Moreover, a timing attack allows the estimation of part of the key due to the existent relationship between this part of the key and the encryption/decryption time. As a result, the main features of the cryptosystem do not satisfy the demands of secure communications. Some hints are offered to improve the cryptosystem under study according to those requirements.
In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a u... more In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a uniform distribution in his ciphertext. To increase the security, we use the logistic map and a 3-dimensional piecewise linear chaotic map in the generation of the associations tables. Simulation results show that performance and security of the proposed cryptographic scheme are better than the Baptista algorithm.
Nonlinear Dynamics, 2015
ABSTRACT Nonlinear delay differential system (NDDS) is a family of hyperchaotic systems, which ha... more ABSTRACT Nonlinear delay differential system (NDDS) is a family of hyperchaotic systems, which has attracted much attention in the last years, especially in optics. The NDDS is often modeled by a time delay that occurs between the signals at the input and the output, and a nonlinearity introduced by a function \(F\) . This paper introduces the Ikeda system that is considered system of infinite dimension and proposed an image encryption scheme by dynamic block. The encryption algorithm divides the image on dynamic blocks depending on the previous block cipher. The algorithm diffuses the plain image with bitwise XOR between each block and sequence generated by Ikeda system after quantification. Statistical analysis of the proposed encryption scheme demonstrates that this cryptosystem is secure enough to resist the brute-force attack, entropy attack, differential attack, chosen-plaintext attack, known-plaintext attack and statistical attack. In addition, the cryptosystem has high sensitivity of key and large space key.
2013 5th International Conference on Modeling, Simulation and Applied Optimization, ICMSAO 2013, 2013
In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a u... more In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a uniform distribution in his ciphertext. To increase the security, we use the logistic map and a 3-dimensional piecewise linear chaotic map in the generation of the associations tables. Simulation results show that performance and security of the proposed cryptographic scheme are better than the Baptista algorithm.
This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P,... more This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P, Li Z, Halang WA, Chen G. A stream cipher based on a spatiotemporal chaotic system. Chaos, Solitons & Fractals 2007;32:1867-76]. The cryptosystem under study displays weakness in the generation of the keystream. The encryption is made by generating a keystream mixed with blocks generated from the plaintext. The so obtained keystream remains unchanged for every encryption procedure. Moreover, its generation does neither depend on the plaintext nor on the ciphertext, that's to say, the keystream remains unchangeable for every plaintext with the same length. Guessing the keystream leads to guessing the key. This paper presents three possible attacks able to break the whole cryptosystem based on this drawback in generating the keystream.
This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P,... more This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P, Li Z, Halang WA, Chen G. A stream cipher based on a spatiotemporal chaotic system. Chaos, Solitons & Fractals 2007;32:1867-76]. The cryptosystem under study displays weakness in the generation of the keystream. The encryption is made by generating a keystream mixed with blocks generated from the plaintext. The so obtained keystream remains unchanged for every encryption procedure. Moreover, its generation does neither depend on the plaintext nor on the ciphertext, that's to say, the keystream remains unchangeable for every plaintext with the same length. Guessing the keystream leads to guessing the key. This paper presents three possible attacks able to break the whole cryptosystem based on this drawback in generating the keystream.
The chaos-based cryptographic algorithms have suggested some new ways to develop efficient image-... more The chaos-based cryptographic algorithms have suggested some new ways to develop efficient image-encryption schemes. While most of these schemes are based on low-dimensional chaotic maps, it has been proposed recently to use high-dimensional chaos namely spatiotemporal chaos, which is modeled by one-way coupled-map lattices (OCML). Owing to their hyperchaotic behaviour, such systems are assumed to enhance the cryptosystem security. In this paper we propose an OCML-based color-image encryption scheme with a stream cipher structure. We use a 192-bit-long external key to generate the initial conditions and the parameters of the OCML.
Compactons are compactly supported solitary waves for nondissipative evolution equations with non... more Compactons are compactly supported solitary waves for nondissipative evolution equations with nonlinear dispersion. In applications, these model equations are accompanied by dissipative terms which can be treated as small perturbations. We apply the method of adiabatic perturbations to compactons governed by the Kðn; nÞ Rosenau-Hyman equation in the presence of dissipative terms preserving the ''mass'' of the compactons. The evolution equations for both the velocity and the amplitude of the compactons are determined for some linear and nonlinear dissipative terms: second-, fourth-, and sixth-order in the former case, and second-and fourth-order in the latter one. The numerical validation of the method is presented for a fourth-order, linear, dissipative perturbation which corresponds to a singular perturbation term.
This paper presents a new secure variant of ADPCM encoders that are adopted by the CCITT as Adapt... more This paper presents a new secure variant of ADPCM encoders that are adopted by the CCITT as Adaptive Differential Pulse Code Modulation. This version provides encryption and decryption of voice simultaneously with operations ADPCM encoding and decoding. The evaluation of the scheme showed better performance in terms of speed and security.
Recently a new image encryption method based on DNA encoding and chaotic systems has been propose... more Recently a new image encryption method based on DNA encoding and chaotic systems has been proposed. In this paper, several weaknesses of this cryptosystem are pointed out. Equivalent mathematical model of the cryptosystem is designed and algebraic analysis is given. Moreover reduction of the key space have been reached by finding equivalent keys. A recovering scheme is finally given with a lower complexity than the actual decryption scheme.
Advanced Materials Research, 2014
ABSTRACT
2009 6th International Multi-Conference on Systems, Signals and Devices, SSD 2009, 2009
In this paper we present a novel fragile watermarking technique which is obviously sensitive to f... more In this paper we present a novel fragile watermarking technique which is obviously sensitive to forgery and Vector Quantization attacks. The proposed scheme acts in the spatial domain and has the ability to localize the modifications undergone to the authenticated image, and recover tampered regions. To increase the security of our method, a chaotic map is used in different stages in the watermarking process. Indeed, it is used to mix the logo pixels and choose the LSB which carry out the information. The authentication and recovery information are inserted in the three LSBs of the gray level pixels. Simulation results show that the proposed method is fast, secure and capable of detecting and recovering the tamper with a good quality.
2010 7th International Multi-Conference on Systems, Signals and Devices, SSD-10, 2010
ABSTRACT Fragile watermarking is used to determine if a digital content has been tampered, and lo... more ABSTRACT Fragile watermarking is used to determine if a digital content has been tampered, and localize tampered regions without referring to the original content. In this paper, we present a novel fragile watermarking technique for tamper detection in gray level images. The proposed method is efficient for simple and intelligent attacks such as collage attack and Vector quantization attack. The embedding process of the watermark starts from computing the Eigen values of the chaotically mixed image and that stands for the watermark, followed by inserting it into the LSBs chosen using the logistic map. The chaotic map is used to improve the security of our algorithm and to contribute with the Eigen values computation by making the watermark as unique as possible in order to face off intelligent attacks. Simulation results show that the presented method is fast, secure and performant in detecting and localising tamper.
Communications in Nonlinear Science and Numerical Simulation, 2011
In this work, we cryptanalyse a recently chaos based cryptosystem on DSP by proposing three diffe... more In this work, we cryptanalyse a recently chaos based cryptosystem on DSP by proposing three different attacks to break it. We report the weakness of this cryptosystem and hence demonstrate that in its actual design, it can not be used in the real world applications and it needs to be first enhanced by avoiding the design drawbacks reported in this work.
Multimedia Tools and Applications, 2013
In this paper, we propose to cryptanalyse an encryption algorithm which combines a DNA addition a... more In this paper, we propose to cryptanalyse an encryption algorithm which combines a DNA addition and a chaotic map to encrypt a gray scale image. Our contribution consists on, at first, demonstrating that the algorithm, as it is described, is non-invertible, which means that the receiver cannot decrypt the ciphered image even if he posses the secret key. Then, a chosen plaintext attack on the invertible encryption block is described, where, the attacker can illegally decrypt the ciphered image by a temporary access to the encryption machinery.
Telecommunication Systems, 2013
In this paper, we propose to enhance a recently proposed image cryptosystem based on hyper-chaos.... more In this paper, we propose to enhance a recently proposed image cryptosystem based on hyper-chaos. The updated version has been builded to resist against attacks made to break the original one and to make it faster. The modification touch on the two Boxes, P-Box and S-Box, which composed the original cryptosystem. Compared with classical encryption scheme, AES and Triple-DES, the new version of the cipher shows a better performances in rapidity, in confusion and in the key sensitivity.
2009 6th International Multi-Conference on Systems, Signals and Devices, 2009
... the attacks pro-posed in [2]. The proposed modified algorithm have also a better performance ... more ... the attacks pro-posed in [2]. The proposed modified algorithm have also a better performance than ... is the shuffled image, T is the permutation matrix and is the transpose function of a ... The design of the modified cryp-tosystem consists on designing the cryptosystem in a CBC ...
Chaos: An Interdisciplinary Journal of Nonlinear Science, 2008
This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the... more This paper reports a detailed cryptanalysis of a recently proposed encryption scheme based on the logistic map. Some problems are emphasized concerning the key space definition and the implementation of the cryptosystem using floating-point operations. It is also shown how it is possible to reduce considerably the key space through a ciphertext-only attack. Moreover, a timing attack allows the estimation of part of the key due to the existent relationship between this part of the key and the encryption/decryption time. As a result, the main features of the cryptosystem do not satisfy the demands of secure communications. Some hints are offered to improve the cryptosystem under study according to those requirements.
In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a u... more In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a uniform distribution in his ciphertext. To increase the security, we use the logistic map and a 3-dimensional piecewise linear chaotic map in the generation of the associations tables. Simulation results show that performance and security of the proposed cryptographic scheme are better than the Baptista algorithm.
Nonlinear Dynamics, 2015
ABSTRACT Nonlinear delay differential system (NDDS) is a family of hyperchaotic systems, which ha... more ABSTRACT Nonlinear delay differential system (NDDS) is a family of hyperchaotic systems, which has attracted much attention in the last years, especially in optics. The NDDS is often modeled by a time delay that occurs between the signals at the input and the output, and a nonlinearity introduced by a function \(F\) . This paper introduces the Ikeda system that is considered system of infinite dimension and proposed an image encryption scheme by dynamic block. The encryption algorithm divides the image on dynamic blocks depending on the previous block cipher. The algorithm diffuses the plain image with bitwise XOR between each block and sequence generated by Ikeda system after quantification. Statistical analysis of the proposed encryption scheme demonstrates that this cryptosystem is secure enough to resist the brute-force attack, entropy attack, differential attack, chosen-plaintext attack, known-plaintext attack and statistical attack. In addition, the cryptosystem has high sensitivity of key and large space key.
2013 5th International Conference on Modeling, Simulation and Applied Optimization, ICMSAO 2013, 2013
In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a u... more In this paper, we propose a new cryptosystem that is faster than that of Baptista and present a uniform distribution in his ciphertext. To increase the security, we use the logistic map and a 3-dimensional piecewise linear chaotic map in the generation of the associations tables. Simulation results show that performance and security of the proposed cryptographic scheme are better than the Baptista algorithm.
This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P,... more This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P, Li Z, Halang WA, Chen G. A stream cipher based on a spatiotemporal chaotic system. Chaos, Solitons & Fractals 2007;32:1867-76]. The cryptosystem under study displays weakness in the generation of the keystream. The encryption is made by generating a keystream mixed with blocks generated from the plaintext. The so obtained keystream remains unchanged for every encryption procedure. Moreover, its generation does neither depend on the plaintext nor on the ciphertext, that's to say, the keystream remains unchangeable for every plaintext with the same length. Guessing the keystream leads to guessing the key. This paper presents three possible attacks able to break the whole cryptosystem based on this drawback in generating the keystream.
This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P,... more This paper proposes three different attacks on a recently proposed chaotic cryptosystem in [Li P, Li Z, Halang WA, Chen G. A stream cipher based on a spatiotemporal chaotic system. Chaos, Solitons & Fractals 2007;32:1867-76]. The cryptosystem under study displays weakness in the generation of the keystream. The encryption is made by generating a keystream mixed with blocks generated from the plaintext. The so obtained keystream remains unchanged for every encryption procedure. Moreover, its generation does neither depend on the plaintext nor on the ciphertext, that's to say, the keystream remains unchangeable for every plaintext with the same length. Guessing the keystream leads to guessing the key. This paper presents three possible attacks able to break the whole cryptosystem based on this drawback in generating the keystream.
The chaos-based cryptographic algorithms have suggested some new ways to develop efficient image-... more The chaos-based cryptographic algorithms have suggested some new ways to develop efficient image-encryption schemes. While most of these schemes are based on low-dimensional chaotic maps, it has been proposed recently to use high-dimensional chaos namely spatiotemporal chaos, which is modeled by one-way coupled-map lattices (OCML). Owing to their hyperchaotic behaviour, such systems are assumed to enhance the cryptosystem security. In this paper we propose an OCML-based color-image encryption scheme with a stream cipher structure. We use a 192-bit-long external key to generate the initial conditions and the parameters of the OCML.
Compactons are compactly supported solitary waves for nondissipative evolution equations with non... more Compactons are compactly supported solitary waves for nondissipative evolution equations with nonlinear dispersion. In applications, these model equations are accompanied by dissipative terms which can be treated as small perturbations. We apply the method of adiabatic perturbations to compactons governed by the Kðn; nÞ Rosenau-Hyman equation in the presence of dissipative terms preserving the ''mass'' of the compactons. The evolution equations for both the velocity and the amplitude of the compactons are determined for some linear and nonlinear dissipative terms: second-, fourth-, and sixth-order in the former case, and second-and fourth-order in the latter one. The numerical validation of the method is presented for a fourth-order, linear, dissipative perturbation which corresponds to a singular perturbation term.
This paper presents a new secure variant of ADPCM encoders that are adopted by the CCITT as Adapt... more This paper presents a new secure variant of ADPCM encoders that are adopted by the CCITT as Adaptive Differential Pulse Code Modulation. This version provides encryption and decryption of voice simultaneously with operations ADPCM encoding and decoding. The evaluation of the scheme showed better performance in terms of speed and security.
Recently a new image encryption method based on DNA encoding and chaotic systems has been propose... more Recently a new image encryption method based on DNA encoding and chaotic systems has been proposed. In this paper, several weaknesses of this cryptosystem are pointed out. Equivalent mathematical model of the cryptosystem is designed and algebraic analysis is given. Moreover reduction of the key space have been reached by finding equivalent keys. A recovering scheme is finally given with a lower complexity than the actual decryption scheme.
Advanced Materials Research, 2014
ABSTRACT
2009 6th International Multi-Conference on Systems, Signals and Devices, SSD 2009, 2009
In this paper we present a novel fragile watermarking technique which is obviously sensitive to f... more In this paper we present a novel fragile watermarking technique which is obviously sensitive to forgery and Vector Quantization attacks. The proposed scheme acts in the spatial domain and has the ability to localize the modifications undergone to the authenticated image, and recover tampered regions. To increase the security of our method, a chaotic map is used in different stages in the watermarking process. Indeed, it is used to mix the logo pixels and choose the LSB which carry out the information. The authentication and recovery information are inserted in the three LSBs of the gray level pixels. Simulation results show that the proposed method is fast, secure and capable of detecting and recovering the tamper with a good quality.
2010 7th International Multi-Conference on Systems, Signals and Devices, SSD-10, 2010
ABSTRACT Fragile watermarking is used to determine if a digital content has been tampered, and lo... more ABSTRACT Fragile watermarking is used to determine if a digital content has been tampered, and localize tampered regions without referring to the original content. In this paper, we present a novel fragile watermarking technique for tamper detection in gray level images. The proposed method is efficient for simple and intelligent attacks such as collage attack and Vector quantization attack. The embedding process of the watermark starts from computing the Eigen values of the chaotically mixed image and that stands for the watermark, followed by inserting it into the LSBs chosen using the logistic map. The chaotic map is used to improve the security of our algorithm and to contribute with the Eigen values computation by making the watermark as unique as possible in order to face off intelligent attacks. Simulation results show that the presented method is fast, secure and performant in detecting and localising tamper.
Communications in Nonlinear Science and Numerical Simulation, 2011
In this work, we cryptanalyse a recently chaos based cryptosystem on DSP by proposing three diffe... more In this work, we cryptanalyse a recently chaos based cryptosystem on DSP by proposing three different attacks to break it. We report the weakness of this cryptosystem and hence demonstrate that in its actual design, it can not be used in the real world applications and it needs to be first enhanced by avoiding the design drawbacks reported in this work.
Multimedia Tools and Applications, 2013
In this paper, we propose to cryptanalyse an encryption algorithm which combines a DNA addition a... more In this paper, we propose to cryptanalyse an encryption algorithm which combines a DNA addition and a chaotic map to encrypt a gray scale image. Our contribution consists on, at first, demonstrating that the algorithm, as it is described, is non-invertible, which means that the receiver cannot decrypt the ciphered image even if he posses the secret key. Then, a chosen plaintext attack on the invertible encryption block is described, where, the attacker can illegally decrypt the ciphered image by a temporary access to the encryption machinery.
Telecommunication Systems, 2013
In this paper, we propose to enhance a recently proposed image cryptosystem based on hyper-chaos.... more In this paper, we propose to enhance a recently proposed image cryptosystem based on hyper-chaos. The updated version has been builded to resist against attacks made to break the original one and to make it faster. The modification touch on the two Boxes, P-Box and S-Box, which composed the original cryptosystem. Compared with classical encryption scheme, AES and Triple-DES, the new version of the cipher shows a better performances in rapidity, in confusion and in the key sensitivity.
2009 6th International Multi-Conference on Systems, Signals and Devices, 2009
... the attacks pro-posed in [2]. The proposed modified algorithm have also a better performance ... more ... the attacks pro-posed in [2]. The proposed modified algorithm have also a better performance than ... is the shuffled image, T is the permutation matrix and is the transpose function of a ... The design of the modified cryp-tosystem consists on designing the cryptosystem in a CBC ...