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We report a charge-based analytic and explicit compact model for field effect transistors (FETs) based on two-dimensional materials (2DMs), for the simulation of 2DMbased analog and digital circuits. The device electrostatics is handled by invoking 2D density of states and Fermi-Dirac statistics, that are later combined with Lambert-W function and Halley's correction, so to eventually obtain explicit expressions for the electron and hole charges, which are exploited in the calculation of drift-diffusion currents for both carriers. Further, the charge model is extended to obtain characteristics of 2DMbased negative capacitance FETs. The model is benchmarked against experimental MoS2 FET measurements, and experimental ambipolar characteristics of narrow band-gap materials such as black phophorous. Its soundness for SPICE circuit-level simulations is also demonstrated.

The memristor, the fourth fundamental elements have shown the potential to revolutionize the present storage, analog, and digital computational technologies. The ability to remember its previous state in the absence of any stimuli has made the memristor as a prime candidate for nonvolatile memory. However, the sneak path is one of the main problems hampering the implementation of memristor‐based crossbar memories. In this article, we introduce a new crossbar architecture that is capable of storing multibit per cell and eliminates the sneak paths without adding any complex circuitry. The approximate write delay of the proposed memory cell is 20 mS which is very close to the delay of the single bit cell. The proposed architecture was validated by storing four different logic states in each cell of the 4 × 4 memory. Hence, one memory cell of the proposed architecture replaces four cells of the single‐bit memory at the cost of one additional diode per cell. Therefore, the proposed scheme saves considerable area when compared with the conventional single‐bit memory array. The write/read operations are validated by a generic, accurate, and efficient “voltage threshold adaptive memristor” (VTEAM) model. The simulation results prove that the proposed circuitry can read the memory content even after 2000 cycles without any sneak paths problem.

In this paper, a new secret data hiding and communication is proposed for natural images.in this proposed methodology. The aim of steganography is to hide an information message within harmless cover medium in such way that it's not possible even to observe that secrete message. It doesn't replace cryptography however rather boosts the security using its obscurity options. In the projected its obscurity features. In the proposed algorithm we have used second order differential equation to hide the data which improve the security level of hidden data. In encryption, information is transformed in such a way that it cannot be detect by hacker. But during encryption, message is changed so it become distorted and intruder may suspect about the presence of important information. For this skin tone detection is performed using HSV (Hue, Saturation and Value) color space. Additionally secret data embedding is performed victimization frequency domain approach-DWT (Discrete wavelet Transform), DWT outperforms than DCT (Discrete cosine Transform). Secret information is hidden in one of the high frequency sub-band of DWT by tracing skin pixels therein sub-band. Totally different steps of data hiding are applied by cropping a picture interactively. The output of our technique provides higher results because with the assistance of cropping an increased security than hiding data while not cropping i.e. in whole image, thus cropped region works as a key at decryption aspect. thus with this object destined steganography we have a tendency to track skin tone objects in image with the higher security and satisfactory PSNR (Peak-Signal-to-Noise Ratio).Modern steganography's goal is to stay its more presence undetectable.

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The digital signature technique is essential for secure transactions over open networks. It is used in a variety of applications to ensure the integrity of data exchanged or stored and to prove to the recipient the originator's identity. Digital signature schemes are mostly used in cryptographic protocols to provide services like entity authentication, authenticated key transport and authenticated key agreement. This architecture is related with secure Hash Function and cryptographic algorithm In this paper we are going to make review about all those technique that are developed within last 5-10 years. And which are developed with the help of digital signature and based on public key cryptography. These techniques provides a better platform for security of data using cryptography.

In this paper, the performance analysis of OFDM based system using turbo and LDPC coding technique is presented under Nakagami-m fading channel. Nakagami-m is very recent and useful tool to evaluate the channel performance for OFDM system. The optimum value of parameter m = 1.4 is used in this paper. Here comparative analysis of turbo coding and LDPC coding schemes shows that error performance of LDPC is much better as compared to turbo codes. Both coding scheme revels the enhancement in BER performance in Nakagami-m channel.

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