A new steganography technique using knight's tour algorithm, affine cipher and huffman coding

• Main Author: Mohsin, Alla Talib (Author)
• Format: Thesis
• Published: 2013-07.
• Subjects: QA75 Electronic computers. Computer science; Thesis
• Online Access: Get fulltext

 Steganography is a way to conceal secret message under a cover image, and is one of the most widespread approaches of securing information. The challenge of steganographic methods is to find a balanced trade-off between visual quality and capacity. In addition, robustness and security are also important that need to be considered. The Least Significant Bit (LSB) insertion approach is one of the most popular steganographic techniques, which can provide both high visual quality and large capacity. However, the LSB approach suffers from robustness and security. Thus, this study proposes a new steganography approach that involves five phases: (i) RGB colour cover image is converted to YCbCr colour space. Then, Cb component is selected to hide the secret data. (ii) The secret message is encrypted by using the Affine Cipher. (iii) The encrypted message is then compressed using the Huffman Coding. (iv) The Knight Tour algorithm is applied to embed the secret code onto the Cb component using LSB approach. (v) Once completed, the Cb is merged with the Y and Cr components and is subsegueatiy converted to RGB image to obtain a stego-image. Experimental results showed that not only has the proposed method improved the security and capacity as compared to the last LSB method, it has also increased the visual quality of the stego-image.