A Secure Cyclic Steganographic Technique for Color Images using Randomization

There are five different types of steganography based on the carrier object that is used for embedding the secret information. The carrier object may be images, text, videos, audios or network protocol packets. If the image is used as a carrier, it is called image steganography. Similarly if video is used for hiding secret messages, we call it video steganography and so on[1, 5]. The diagrammatic representation of different types of steganography is shown in Fig. 1.The types of steganography are: a. Audio Steganography b. Image Steganography c. Video Steganography d. Text Steganography e. Network Steganography Fig. 1. Types of Steganography w.r.t carrier object 1.2 Types of Steganography w.r.t Key Exchange To make the steganographic algorithm more robust against different fraudulent behaviors, the idea of using secret key and public key was introduced. When secret key and public keys are used in steganography, a mechanism should be there via which these keys can be securely exchanged. Usually one or two keys are used in the process of steganography; public key that is used to embed secret information into the carrier object and secret or private key that has a mathematical relationship with public key and is used for extraction of secret data from stego object [6]. On the basis of exchange of keys, there are three types of steganography as shown in Fig. 2. 57 Abstract-Information Security is a major concern in today's modern era. Almost all the communicating bodies want the security, confidentiality and integrity of their personal data. But this security goal cannot be achieved easily when we are using an open network like Internet. Steganography provides one of the best solutions to this problem. This paper represents a new Cyclic Steganographic Technique (CST) based on Least Significant Bit (LSB) for true color (RGB) images. The proposed method hides the secret data in the LSBs of cover image pixels in a randomized cyclic manner. The proposed technique is evaluated using both subjective and objective analysis using histograms changeability, Peak Signal-to-Noise Ratio (PSNR) and Mean Square Error (MSE). Experimentally it is found that the proposed method gives promising results in terms of security, imperceptibility and robustness as compared to some existent methods and vindicates this new algorithm.