Certain investigations on cryptography and steganography Techniques in compressed video

Abstract

With the rapid development and advances of technologies in digital communication, security plays an important concern in wireless transmission. In real time applications such as online banking, E-commerce, the multimedia data is transmitted through online platform and there is a chance of hacking of data. So, to securely transmit the data, data hiding techniques are needed which provides protection, authenticity, integrity and robustness to the data. Cryptography, steganography and watermarking are the classifications of data hiding techniques. The combination of crypto-stegano techniques are proposed in this research work to provide enhanced protection to the secret multimedia input data. In the proposed models, the input secret data considered for testing is an either text or an image which are mostly used to convey the information from the sender to the recipient. Reversible Data Hiding (RDH) with Morse code based text encryption and wavelet based compressed video steganography model is proposed initially. In this model, text data is taken as a secret data and compressed video is selected as a cover file for embedding. Text data encryption is performed by Morse code which is the easiest method for encrypting data in the form of dots and dashes. Wavelets (Haar and Daubechies) based cover frame compression is used for compressing the cover frame which is already obtained from the compressed cover video and encrypted text is embedded into the compressed cover frame using logical operations. Password facility is included to enhance the authenticity of the recipient at the receiver side. So the combination of crypto-stegano techniques with password facility gives three level security to the secret text data while transmitting it through a digital medium. Performance of the proposed model is evaluated by computing the measures Compression Ratio (CR), Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR). At the receiver side, by doing the RDH reversal process, the secret text data and cover frame are retrieved with 100% accuracy and an average PSNR of 24 dB respectively. To enhance the security further, Morse code based text encryption followed by arithmetic compression is proposed with Discrete Shearlet Transform (DST) for compressed video steganography. Morse code with arithmetic compression reduces the length of the encrypted text data so that it consumes minimum space during the embedding phase of steganography. Using DST, provides better CR compared with standard wavelets (Haar and Daubechies). After the reconstruction, at the receiver side, an enhanced average PSNR of 48.4971 dB is obtained when compared with previous Morse code with DWT model. newline