A Secure and Effective Pattern-Based Steganographic Method in Coloured JPEG Images
Abstract- The advent of the Internet and advances in communication have made information ubiquitous. This large availability of information poses risk on its own. Electronic communication is increasingly susceptible to eavesdropping and malicious interventions. Privacy and security are major concerns in this age. In this light, two methods have been brought into existence: Cryptography and Steganography. Cryptography scrambles the message to make it unreadable whereas Steganography masks the existence of the message.
Steganographic methods may be spatial-domain (altering the pixel values to hide data) or frequency-domain techniques (altering the frequency coefficients of the image). Spatial domain techniques are more susceptible to steganalysis unlike the frequency-domain techniques. In this paper, I propose a unique pattern based approach for steganography and extended caesar cipher for cryptography. In this approach, the message is first encrypted using extended caesar cipher and four patterns are selected to hide the message in the image. The hidden message is secured with an AES-encrypted password, adding an extra layer of security. This method is imperceptible to visible attacks, histogram attacks and statistical attacks since the alterations produced by the method do not bring about a detectable change in the resulting image. Thus, this method provides a new insight into a more secure, efficient and flexible steganographic technique.
Keywords—Discrete Cosine Transform, Payload, Peak Signal to Noise Ratio, Cover Image, Stego Image
