Performance comparison between Chaos and quantum-chaos based image encryption techniques

Multimedia Tools and Applications - Today’s digital era has undertaken most of the responsibilities of public and private sectors, not only the industries or big organizations dependent on...     

Assessment of diverse image encryption mechanisms under prevalent invasion

Multimedia Tools and Applications - Image encryption mechanisms provide confidentiality and concealment of information (image) in transmission over the alleyway, susceptible to prevalent invasions....     

A multi-level steganography mechanism using quantum chaos encryption

Multimedia Tools and Applications - Recent advances in processing capabilities of hardware devices and 5 g spectrum availability has not only made the life of users heaven but has also...     

An innovative image encryption scheme based on chaotic map and Vigenère scheme

Multimedia Tools and Applications - Confidentiality of images during data communication is a prime concern of many researchers, as a result, several mechanisms have been proposed for image...     

Publicly verifiable watermarking scheme for intellectual property protection using quantum Chaos and bit plane complexity slicing

Intellectual Property such as music, painting, videos and other similar works being broadcasted on web need to be protected against copyright infringement to ensure the rights of their legitimate owners. Moreover, their users must also be sure of the originality of these artefacts. Both these problems can be solved through proper authentication on behalf of the creator. For this purpose, various publicly verifiable watermarking schemes have been available in literature. Recent proposal, in this domain, is based on chaos theory and Secured Hashing Algorithms SHA-2. Due to tremendous growth in the availability of Intellectual Property on the web and associated breaches it becomes a mandatory requirement to update these authenticating schemes. This paper proposes the usage of some more secure, reliable and efficient components in watermarking schemes than being used at present. Proposed changes include the deployment of encryption scheme based on Quantum Logistic maps instead of current Chaos encryption based on peter de-jong map, in order to optimise randomness, correlation and time complexity. For better security and efficiency in hardware implementation SHA-3 is a better choice than SHA-2. Data embedding can be done in regions where imperceptibility is quite high. The proposed changes can result in the creation of more reliable and efficient system. To test the hypothesis, proposed mechanism has been implemented in MATLAB-16a and various performance metrics such as correlation coefficient, PSNR, UIQI, SSIM have been measured. The results show that proposed scheme outperforms its counterpart in terms of all the performance metrics.     

Photovoltaic properties of liquid-state photoelectrochemical cells based on PPAT and a composite film of PPAT and nanocrystalline titanium dioxide

We have studied the optical and photoelectrical properties of liquid state photoelectrochemical cells (PECs) based on photoactive electrodes based on poly (phenyl azo methane thiophene) (PPAT) and a composite film of nano-crystalline titanium dioxide (nc-TiO₂) and PPAT. The device fabricated with nc-TiO₂/PPAT photoactive electrode shows better performance with an open circuit voltage (V_oc) 0.56 V, short circuit photocurrent (J_sc) = 0.87 mA/cm² and fill factor (FF) = 0.58 under illumination with white light intensity of 10 mW/cm². We have analyzed the experimental results by comparing the IPCE spectra of both devices. It is observed that the device with nc-TiO₂/PPAT photoactive electrode shows better photovoltaic response as compared to the device based on PPAT photoactive electrode. This indicates that PPAT shows its p-type semiconducting behavior in the device based on PPAT, while in the device based on nc-TiO₂/PPAT photoactive electrode, the PPAT acts as a sensitizer to nano-crystalline TiO₂. The PEC based on TiO₂/PPAT photoelectrode exhibit an exponential increase of low frequency device capacitance due to the diffusion of electrons along TiO₂ network. Effect of iodine doping in PPAT on the photovoltaic performance of PEC have been also studied.     

Analysis of traditional and modern image encryption algorithms under realistic ambience

Multimedia Tools and Applications - Cryptography (encryption/decryption) is one of the prevailing mechanisms for protection of information (data or image) in the growing era of computerized...     

An efficient hybrid security mechanism based on chaos and improved BPCS

Commonly used security mechanisms such as cryptography and steganography suffer from weaknesses when used in a standalone manner. Extra efforts in the form of additional permutations/diffusions etc. result in higher ciphering/deciphering time complexity. Thus, there is a requirement for a security mechanism(s) which can provide adequate security without putting a considerable burden on ciphering/deciphering time complexity. This paper is an effort in this direction. The paper proposes a hybrid mechanism that employs chaotic based encryption scheme to encrypt data and an improved Bit-Plane Complexity Segmentation Steganography algorithm to embed the data. The proposed mechanism uses two new complexity measures to differentiate between noisy regions and simple ones appropriately. The scheme was implemented in MATLAB, and the simulation results show that the proposed mechanism has high embedding capacity, high security with a moderate decrease in PSNR value and is computationally fast.     

Power Control for Packet Voice Service with Application to EDGE Wireless System

Using the enhanced data rates for GSM evolution (EDGE) system with cyclic frequency hopping as an example, we apply a Kalman-filter power control method based on interference tracking to packet voice service in wireless networks. Our results show that the power-control method significantly improves the spectral efficiency by enabling the 1/3 frequency reuse while maintaining a stringent requirement of 2% packet loss probability for voice service. Specifically, for allocated spectrum of 1.8, 3.6 and 5.4 MHz, the 1/3 reuse with the Kalman power control can yield 102.5%, 49.5% and 32.5% improvement in spectral efficiency, respectively, over the 3/9 reuse (regardless of whether or not power control is used). We also compare the performance of the Kalman method with a traditional Signal-to-interference-ratio method and a control method that is based on the last interference measurement. We find that appropriate selection of power for the first packet of each talk spurt and the filtering function for noisy measurements are crucial in providing high system capacity for packet voice service. For the EDGE system, we also identify a need for shortening the power update period, which is 480 ms in the specifications.