Farman Ullah | Comsats University Islamabad (original) (raw)

Papers by Farman Ullah

IEEE Access, 2024

In the 21st century, the digital era, chaotic systems become the backbone in designing the secure... more In the 21st century, the digital era, chaotic systems become the backbone in designing the secure ciphers for image cryptography because of their intrinsic features like dynamical behavior and sensitivity to initial conditions. In this regard, 1-dimensional (1D) non-linear dynamical systems are one of the most studied in chaos theory. Besides the advantages of 1D chaotic systems, these systems have short periods and a short range of control parameters. A new 1D chaotic system called as Cosine Chaotic Equation (CCE) was developed to address this issue. The new and simple chaotic system has a larger range of control parameters α which increases the key space to make brute force attacks infeasible. The system is rigorously tested using the randomness evaluation metrics SP800-22 test suite recommended by the National Institute of Standards and Technology (NIST). It proved itself as an excellent addition in the pool of 1D chaotic systems to use safely in designing new ciphers. The new dynamical system is applied in an image encryption technique to prove its efficacy. INDEX TERMS Cryptography, pseudo-random number generator (PRNG), CCE, chaos theory, non-linear dynamical system, image encryption.

IEEE Access, 2020

An innovative method proposed for encrypting color images is comprised of one-time keys and chaos... more An innovative method proposed for encrypting color images is comprised of one-time keys and chaos theory using a distinctive concept of rotor machine. The novelty of this scheme is that the rows and columns of 2-dimensional images are converted into circular object called rotor and can be rotated at 360 degrees in clockwise or anti clockwise direction. The rotation will change the existing rotor into new one and can be used in substitution process of plain image. This process can be repeated β times and each time a new rotor is created just by a simple rotation. The rotation is performed in terms of pixels so degree of angle is converted into number of pixels. Using this method, same object with new face (after rotation) is used for encryption. The pixels of color image are permuted using the sorted index of logistic sequence. Then, three pseudo-random images are created from Piecewise Linear Chaotic Map (PWLCM). For substitution, both the permuted color channels and pseudo-random images are transformed into rotors. The angle is obtained from Chen chaotic system. The one-time keys are for chaotic maps are generated by using 512-bits hash of plain image. The simulated outcomes demonstrate that the proposed system has high quality of results and requires only single round of encryption to achieve high encryption along with high robustness against the transmission noises. INDEX TERMS Chaos theory, color image encryption, SHA-512, rotor machine, one time key. AQEEL UR REHMAN received the M.Sc. degree in computer science from The Islamia University of Bahawalpur, the second master's degree in computer engineering from UET Taxila (CASE campus) Islamabad, Pakistan, and the Ph.D. degree in computer science and technology from Chongqing University, China. He worked as an Assistant Professor with the Department Computer Sciences,

IEEE Access, 2020

An innovative method proposed for encrypting color images is comprised of one-time keys and chaos... more An innovative method proposed for encrypting color images is comprised of one-time keys and chaos theory using a distinctive concept of rotor machine. The novelty of this scheme is that the rows and columns of 2-dimensional images are converted into circular object called rotor and can be rotated at 360 degrees in clockwise or anti clockwise direction. The rotation will change the existing rotor into new one and can be used in substitution process of plain image. This process can be repeated β times and each time a new rotor is created just by a simple rotation. The rotation is performed in terms of pixels so degree of angle is converted into number of pixels. Using this method, same object with new face (after rotation) is used for encryption. The pixels of color image are permuted using the sorted index of logistic sequence. Then, three pseudo-random images are created from Piecewise Linear Chaotic Map (PWLCM). For substitution, both the permuted color channels and pseudo-random images are transformed into rotors. The angle is obtained from Chen chaotic system. The one-time keys are for chaotic maps are generated by using 512-bits hash of plain image. The simulated outcomes demonstrate that the proposed system has high quality of results and requires only single round of encryption to achieve high encryption along with high robustness against the transmission noises. INDEX TERMS Chaos theory, color image encryption, SHA-512, rotor machine, one time key.

IEEE Access, 2024

In the 21st century, the digital era, chaotic systems become the backbone in designing the secure... more In the 21st century, the digital era, chaotic systems become the backbone in designing the secure ciphers for image cryptography because of their intrinsic features like dynamical behavior and sensitivity to initial conditions. In this regard, 1-dimensional (1D) non-linear dynamical systems are one of the most studied in chaos theory. Besides the advantages of 1D chaotic systems, these systems have short periods and a short range of control parameters. A new 1D chaotic system called as Cosine Chaotic Equation (CCE) was developed to address this issue. The new and simple chaotic system has a larger range of control parameters α which increases the key space to make brute force attacks infeasible. The system is rigorously tested using the randomness evaluation metrics SP800-22 test suite recommended by the National Institute of Standards and Technology (NIST). It proved itself as an excellent addition in the pool of 1D chaotic systems to use safely in designing new ciphers. The new dynamical system is applied in an image encryption technique to prove its efficacy. INDEX TERMS Cryptography, pseudo-random number generator (PRNG), CCE, chaos theory, non-linear dynamical system, image encryption.

IEEE Access, 2020

An innovative method proposed for encrypting color images is comprised of one-time keys and chaos... more An innovative method proposed for encrypting color images is comprised of one-time keys and chaos theory using a distinctive concept of rotor machine. The novelty of this scheme is that the rows and columns of 2-dimensional images are converted into circular object called rotor and can be rotated at 360 degrees in clockwise or anti clockwise direction. The rotation will change the existing rotor into new one and can be used in substitution process of plain image. This process can be repeated β times and each time a new rotor is created just by a simple rotation. The rotation is performed in terms of pixels so degree of angle is converted into number of pixels. Using this method, same object with new face (after rotation) is used for encryption. The pixels of color image are permuted using the sorted index of logistic sequence. Then, three pseudo-random images are created from Piecewise Linear Chaotic Map (PWLCM). For substitution, both the permuted color channels and pseudo-random images are transformed into rotors. The angle is obtained from Chen chaotic system. The one-time keys are for chaotic maps are generated by using 512-bits hash of plain image. The simulated outcomes demonstrate that the proposed system has high quality of results and requires only single round of encryption to achieve high encryption along with high robustness against the transmission noises. INDEX TERMS Chaos theory, color image encryption, SHA-512, rotor machine, one time key. AQEEL UR REHMAN received the M.Sc. degree in computer science from The Islamia University of Bahawalpur, the second master's degree in computer engineering from UET Taxila (CASE campus) Islamabad, Pakistan, and the Ph.D. degree in computer science and technology from Chongqing University, China. He worked as an Assistant Professor with the Department Computer Sciences,

IEEE Access, 2020

An innovative method proposed for encrypting color images is comprised of one-time keys and chaos... more An innovative method proposed for encrypting color images is comprised of one-time keys and chaos theory using a distinctive concept of rotor machine. The novelty of this scheme is that the rows and columns of 2-dimensional images are converted into circular object called rotor and can be rotated at 360 degrees in clockwise or anti clockwise direction. The rotation will change the existing rotor into new one and can be used in substitution process of plain image. This process can be repeated β times and each time a new rotor is created just by a simple rotation. The rotation is performed in terms of pixels so degree of angle is converted into number of pixels. Using this method, same object with new face (after rotation) is used for encryption. The pixels of color image are permuted using the sorted index of logistic sequence. Then, three pseudo-random images are created from Piecewise Linear Chaotic Map (PWLCM). For substitution, both the permuted color channels and pseudo-random images are transformed into rotors. The angle is obtained from Chen chaotic system. The one-time keys are for chaotic maps are generated by using 512-bits hash of plain image. The simulated outcomes demonstrate that the proposed system has high quality of results and requires only single round of encryption to achieve high encryption along with high robustness against the transmission noises. INDEX TERMS Chaos theory, color image encryption, SHA-512, rotor machine, one time key.