Information security is one of the most important factors to be considered when secret information has to be communicated between two parties. Cryptography and steganography are the two techniques used for this purpose. Cryptography scrambles the information, but it reveals the existence of the information. Steganography hides the actual existence of the information so that anyone else other than the sender and the recipient cannot recognize the transmission. In steganography the secret information to be communicated is hidden in some other carrier in such a way that the secret information is invisible. In this paper an image steganography technique is proposed to hide audio signal in image in the transform domain using wavelet transform. The audio signal in any format (MP3 or WAV or any other type) is encrypted and carried by the image without revealing the existence to anybody. When the secret information is hidden in the carrier the result is the stego signal. In this work, the results show good quality stego signal and the stego signal is analyzed for different attacks. It is found that the technique is robust and it can withstand the attacks. The quality of the stego image is measured by Peak Signal to Noise Ratio (PSNR), Structural Similarity Index Metric (SSIM), Universal Image Quality Index (UIQI). The quality of extracted secret audio signal is measured by Signal to Noise Ratio (SNR), Squared Pearson Correlation Coefficient (SPCC). The results show good values for these metrics

This paper proposes a secure image steganography technique to hide a secret image using the key. The secret image itself is not hidden, instead a key is generated and the key is hidden in the cover image. Using the key the secret image can be extracted. Integer Wavelet Transform (IWT) is used to hide the key. So it is very secure and robust because no one can realize the hidden information and it cannot be lost due to noise or any signal processing operations. Experimental results show very good Peak Signal to Noise Ratio (PSNR), which is a measure of security. In this technique the secret information is hidden in the middle bit-planes of the integer wavelet coefficients in high frequency sub-bands.

Secret data when transmitted over the network must be protected from the illegal copy, modification or destruction by the malicious user. Audio steganography is a technique that provides a platform for secure transmission of secret data over the internet. In audio steganography, the secret data is transmitted with audio signal as the carrier. This paper proposes a high capacity and security audio steganography technique to hide secret audio signal. In this technique, in lieu to ensconcing the secret information as a whole in the cover object a key corresponding to the secret information is produced and hidden imperceptibly in the cover signal. The key is used to retrieve the secret information. To generate the key and to conceal it in the cover, integer wavelet transform (IWT) is used. The performance metrics obtained are well above the required level of HAS, indicating good security and robustness of the stego system.

Hybrid magnetic tunnel junction/complementary metal oxide semiconductor (MTJ/CMOS) circuits based on in-memory-computation (IMC) architecture is considered as the next-generation candidate for the digital integrated circuits. However, the energy consumption during the MTJ write process is a matter of concern in these hybrid circuits. In this regard, we have developed a novel write circuit for the contemporary three-terminal perpendicular-MTJs that works on the voltage-gated spin orbit torque (VG+SOT) switching mechanism to store the information in hybrid circuits for IMC architecture. Investigation of the novel write circuit reveals a remarkable reduction in the total energy consumption (and energy delay product) of 92.59% (95.81) and 92.28% (42.03%) than the conventional spin transfer torque (STT) and spin-Hall effect assisted STT (SHE+STT) write circuits, respectively. Further, we have developed all the hybrid logic gates followed by nonvolatile full adders (NV-FAs) using VG+SOT, STT, and SHE+STT MTJs. Simulation results show that with the VG+SOT NOR-OR, NAND-AND, XNOR-XOR, and NV-FA circuits, the reduction in the total power dissipation is 5.35% (4.27%), 5.62% (3.2%), 3.51% (2.02%), and 4.46% (2.93%) compared to STT (SHE+STT) MTJs respectively.