This stego image is transferred to the receiver, and he extracts out the secret message using extraction algorithm. As soon as data are embedded using some appropriate embedding algorithm, then it is called stego image. At the sender’s side, the image used for embedding the secret message is called cover image, and the secret information that needs to be protected is called a message. The most popular medium used is image files because of their high capacity and easy availability over the internet. According to Greek history, secret messages were written on the bald scalp of the slaves, and after the growth of hair on their heads, they were sent as messengers. The concept of invisible ink was also used during the period of World War II.
In ancient times, Greeks also wrote messages on wood and covered them with wax. Historical records depict that around 440 BC, Herodotus sent secret messages using the concept of steganography. The word steganography is built up of two words of ancient Greek origin “steganos” meaning “covered, concealed, or protected” and “graphie” meaning “writing.” The concept of steganography is not new its usage can be seen in the past also. Steganography is defined as a science or art of hiding the message inside some cover medium. The cover medium can be in the form of image file, text file, video file, or audio file. In steganography, the data are hidden in the cover media. Steganography proves as a trustable method for achieving this aim. To ensure that the message is transferred securely and safely over the network, a suitable method is needed. Many times, confidentiality of the transferred message needs to be maintained. Through internet, messages can be transferred in a fast and cheap way in various fields like government offices, private sector, military, and medical areas. Internet has emerged as the most convenient and efficient medium for communication. This proposed image steganography showed interesting, promising results when compared with other existing techniques. After implementation, the efficiency of the method is checked on the basis of parameters like PSNR and MSE, and then comparison with some already proposed techniques was done.
On the basis of a combination of these two values, two bits of the message can be hidden on each pixel. The 7th bit of the selected pixel and 7th bit of pixel + 1 are used for information hiding and extraction. On the basis of the 7th bit of the pixels of an image, a mathematical function is applied at the 7th bit of the pixels, which generates a temporary variable (pixel + 1). One bit is hidden at the selected pixel, and the second bit is hidden on the pixel +1 value. In this paper, a method of image coding is proposed that hides the information along a selected pixel and on the next value of the selected pixel, that is, pixel + 1. Image files provide high capacity, and their frequency of availability over the internet is also high. Image steganography has emerged out as the eminent tool of information hiding that ensures the security of the transmitted data. As the internet has become the medium for transferring the sensitive information, the security of the transferred message has become the utmost priority.
0 kommentar(er)
