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Steganography is the art of hiding a secret message in some kind of media. The main goal is not to hide only the secret message but also the existence of communication and secure data transferring. There are a lot of methods that were utilized for building the steganography; such as LSB (Least Significant Bits), Discrete Cosine Transform (DCT), Discrete Fourier Transform, Spread-Spectrum Encoding, and Perceptual Masking, but all of them are challenged by steganalysis. This paper proposes a new technique for Gray Scale Image Steganography that uses the idea of image segmentation and LSB to deal with such problem. The proposed method deals with different types of images by converting them to a virtual gray scale 24 bitmaps, finds out the possible segments inside image and then computes the possible areas for each segment with boundaries. Any intruder trying to find the transformed image will not be able to understand it without the correct knowledge about the transformation process. The knowledge is represented by the key of image segmentation, key of data distribution inside segment (area selection), key of mapping within each area segment, key agreement of cryptography method, key of secret message length and key of message extension. Our method is distinguishing oneself by one master key to generate the area selection key, pixels selection keys and cryptography key. Thus, the existence of secret message is hard to be detected by the steganalysis. Experiment results show that the proposed technique satisfied the main requirements of steganography; visual appearance, modification rate, capacity, undetectability, and robustness against extraction (security). Also it achieved the maximum capacity of cover image with a modification rate equals 0.04 and visual quality for stego-image comparable to cover image.

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Steganography is not only the art of hiding secret messages in cover media but also a process of communication and secure data transfer. Secret messages can be sent over the Internet with security by using several steganography techniques, but all of them present challenges in steganalysis. This study proposes a new secure technique called flash video (FLV) file steganography that keeps the frame video quality and is difficult to detect. The technique can hide any type of secret message inside a given FLV file. The secret message is divided into packets of the same length, reordered packet, and encrypted bytes before being hidden at the end of a selected video tag. A simulated annealing (SA) approach to select tags for steganography is presented to reduce or avoid the challenge of steganalysis. The proposed method uses SA as supporting framework to deal with the FLV file as a host for different types of secret messages. The system determines the minimum path within the host FLV file by using SA and hides the message bits inside each pixel in the minimum computed path. Analysis of the host FLV file cannot be performed without proper knowledge on the transformation process. Thus, the existence of the secret message is difficult to detect by steganalysis. Knowledge is represented by the key of finding the minimum path in the host FLV file, key of secret message length, key of additional bytes, key of message packets reordering and key of message extension. Experimental results show that the proposed technique satisfies the main requirements of steganography with regard to visual appearance, capacity, undetectability, and robustness against extraction.

Internet is a public channel and security issues, such as modification, interception and sniffing normally exist. Steganography is a common security technique that is utilized to solve or reduce those problems. A large number of methods is used for implementing steganography; as least significant bits (LSB), discrete cosine transform (DCT), discrete Fourier transform (DFT), Spread Spectrum coding and Perceptual Masking. This paper proposes a random and sequential LSB to embed the secret message inside the color image. The linear congruent generator (LCG) is a random generator that is used with LSB to hide a stream of bits in a bitmap image (cover image) to give a new image (stego-image) comparable to the cover image. Secret key for random LSB is a combination of four parameters (Seed, Multiplier, Noncommon factor, and Cycle length). The proposed method employees red, green or blue channel to hide the secret message. Selection of channel based on the modification rate for each channel. The minimum modified channel in cover image is utilized to embed the secret message. Results show that random LSB is better than Sequential LSB in term of visual effect while the worst in term of execution time. Random LSB satisfies sufficient security to secret message due to requirements for random function parameters in the extraction process.