Enhancing the security of high payload image steganography using chaos

摘要

One of the biggest technological events of the last two decades is the use of digital media in every aspect of daily life. Digital data can be stored efficiently in a very high quality format, and it can be manipulated very easily using computers. Digital image is one of the most popular digital multimedia data types. Furthermore, digital data can be transmitted in a fast and inexpensive way through data communication networks without losing quality. One of main concerns of these transmissions is security. To overcome this concern and security issues, steganography is one of main techniques that can provide confidentiality. Many steganography algorithms have been proposed. Each of them has its own drawbacks and advantages as well. LSB based technique in spatial domain is one of steganography techniques. Encryption can be simultaneously applied with steganography to increase the confidentiality of data. Among various techniques, chaos based encryption has attracted a lot of research and study due to good characteristics of the chaos systems. Yet, in order to transmit an image in a reasonable amount of time, some techniques must be incorporated to reduce the image’s file size. Jpeg2000 is a welldeveloped image compression technique that can be utilized for this purpose. The common problem of image steganography is the need for imperceptibility for large amount of data. To overcome this problem, this project proposed a technique, S-UCLA (Steganography Using Compression and Lorenz Algorithms). S-UCLA combines KAMLA steganography technique with Lorenz chaotic map encryption and Jpeg2000 compression. The results show better imperceptibility can be obtained in comparison to KAMLA algorithm as PSNR and entropy has improved. Also the histogram for S-UCLA is smoother than KAMLA which showed better confusion and thus can be considered as providing higher confidentiality