Abstract
Secured text data transmission plays an important role in communications. Discrete wavelet transform (DWT) is a time variant transform. The drawback of DWT can be overcome by stationary wavelet transform (SWT). SWT is designed to achieve the translation invariance. This chapter presents a novel secured text data transmission through video steganography using two-level stationary wavelet transform (SWT) and singular value decomposition (SVD). SVD of an image can be factored into its three components. In this chapter, text data is encrypted in cover video file using SWT and SVD techniques. First, the cover video is split into frames and each frame of the video acts as an image. Each character in the text data is encrypted with appropriate key value in each frame of the image using two-level SWT and SVD. The encrypted images are converted into video files that are called stego-video files. The text data can be recovered from the stego-video files after converting these files into frames by applying suitable key values, two-level SWT and SVD techniques.
TopIntroduction
Video steganography changes the digital data in the video in a manner that only the sending person and the corresponding receiving person can recognize the message. The below equation gives a description of steganographic processcover_video + text data + stego_key = stego_video(1) where cover_video is a video file which is used to embed the text data with stego_key values. The output is stego_video. The appearance of stego_video is same as the cover_video. The embedded text data doesn't make the distortion in cover video. (Shivani Khosla, & Paramjeet Kaur, 2014)
Any video file format can be used as a cover video in steganography. But that video file has high degree quality and redundancy. If the redundant bits of the video can be changed then there is no change detected in the video. Video files are suitable for to embed the confidential information. The categories of steganography are shown in Figure 1.
The text staganography method was to conceal a confidential message in every nth letter of every word of a text message (Shivani Khosla, & Paramjeet Kaur, 2014). Digital video contains a set of images(frames). These frames are passed sequentially based on the video standards that constitute a video. In video steganography, each letter in text message is embedded in every frame of the video. This process is very difficult to identify the hidden message in stego video.
Figure 1.
Categories of Steganography
Now a days secured data transmission plays an important role in data communication. Secured data main aim is to protect the data from the demolition forces and data hackers. In order to protect the data on public channels, secured data transmission is needed. There are so many secured techniques are available to transmit the data from source to destination like digital watermarking, audio steganography, video steganography, etc,.
Video stegnography is a promising technique to achieve the secured data transmission from source to destination. Steganography is a greek word, it means “covered writing” or “concealed writing”. Video steganography changes the digital data in the video in a manner that only the sending person and the corresponding receiving person can recognize the message. Steganalysis means that discern the concealed message. The main aim of steganalysis is to meet if an algorithm can determine whether a given video contains confidential information. The confidential information can be hidden into video in a manner that cannot be detectable.
Video steganography is nothing but to hide the text data into video. In video steganography, text data act as a secret message and video act as a cover to the secret message. In this paper, text data is encrypted in cover video file using SWT and SVD techniques. SWT is one of the wavelet transformation techniques. It converts the spatial domain into frequency domain. SWT also provides the edge enhancement to an image. SVD of an image can be factored into its three components.
Key Terms in this Chapter
Cover Video: The video in which information is concealed.
Spatial Domain: The pixel representation of the image is called spatial domain. In spatial domain, the operations are directly applied to pixel values.
Discrete Wavelet Transform: Discrete wavelet transform (DWT) is a time variant transform that is used to find the wavelet coefficients.
Digital Watermarking: The secret image concealed in cover image is called digital watermarking.
Stego Video: The appearing video after the steganography.
SWT Sub-Bands: The sub-bands generated after applying the SWT.
Singular Value Decomposition: It is used to find the factorization of the matrix or image.