Secret communication using Public Key steganography

This paper introduces a new steganographic technique for secret data communication based on Public Key Digital Image steganography by combining public key cryptography with Digital Image Steganography. The proposed scheme employs RSA algorithm with 1024 bits key size for secret data encryption before inserting it into cover image and F5 steganographic technique to hide the encrypted message inside the cover image imperceptibly. The F5 algorithm embeds the message into randomly chosen Discrete Courier Transform (DCT) coefficients. By employing matrix embedding which minimizes the changes to be made to the length of certain message, it provides high Steganographic capacity, faster speed and can prevent visual and statistical attacks. The encryption key used in message encryption is big enough to thwart known cryptanalytic attacks. Experiments suggest that the stego image and cover images are perceptually similar. Further, the stego images are robust against image processing distortions.