Design and Implementation of Secure Public Key Steganography

Several approaches and techniques have been proposed to makecommunication via the internet secure; one of these approaches is steganography.Steganography is the art and science of hiding communication, a steganographicsystem thus embeds hidden content in unremarkable cover media so as not toarouse an eavesdropper’s suspicion. In this research the proposed method is apublic key steganography technique and it embeds a secret message in digitalimage with multi level of security. The proposed method uses Discrete CosineTransform (DCT) to embed a secret message in Bit Mapped Image Format forMicrosoft Windows (BMP) image with high invisibility and high correlationbetween cover-image and stego-image acceptable hiding data rate

A DCT-based Mod4 steganographic method

This paper presents a novel Mod4 steganographic method in discrete cosine transform (DCT) domain. Mod4 is a blind steganographic method. A group of 2 2 spatially adjacent quantized DCT coefficients (GQC) is selected as the valid message carrier. The modulus 4 arithmetic operation is then applied to the valid GQC to embed a pair of bits. When modification is required for data embedding, the shortest route modification scheme is applied to reduce distortion as compared to the ordinary direct modification scheme. Mod4 is capable in embedding information into both uncompressed and JPEG-compressed image. To compare Mod4 with other existing methods, carrier capacity, stego image quality, and results of blind steganalysis for 500 various images are shown. Visual comparison of three additional metrics is also presented to show the relative performance of Mod4 among other existing methods. r 2006 Elsevier B.V. All rights reserved