INFORMATION HIDING USING DIGITAL STEGANOGRAPHY
ABSTRACT
Steganography is the art of hiding the fact that communication is taking place, by hiding information in other information. Many different carrier file formats can be used, but digital images are the most popular because of their frequency on the internet. For hiding secret information in images, there exists a large variety of steganography techniques some are more complex than others and all of them have respective strong and weak points. Different applications may require absolute invisibility of the secret information, while others require a large secret message to be hidden. This project report intends to give an overview of image steganography, its uses and techniques. It also attempts to identify the requirements of a good steganography algorithm and briefly recommended on which stenographic technique are more suitable for which applications.
Chapter one
Introduction
1.1 Background to the study
Currently, the digital information revolution has brought significant changes in our society and daily routines. In line with the revolution, Internet and wireless network offer ubiquitous channels to deliver and exchange information. Therefore, public information exchange is secured by using an encryption method where a secret data can be encrypted to prevent the content from being intercepted. However, with the technological advancement of information security, most Internet users are not aware that sending encrypted messages will draw unnecessary attention to malicious black hats such as crackers and hackers. This is because the encrypted data appears as a string of gibberish data that might arouse suspicion. Moreover, there is a possibility of illegal exploitation attempts to the vulnerability of the encrypted messages due to curiosity and inquisitiveness of a hacker. As a result, the secret data which has been encrypted could be illegally intercepted, unauthorized tampered or even damaged during data transmission.
In order to alleviate the issue mentioned above, steganography is introduced as an alternative design to conceal a secret data into an unsuspicious cover-object so that it can be sent stealthily through a public communication channel without drawing any unnecessary attention of the black hats.
Steganography is derived from the findings of Johannes Trithemus (1462-1516) entitled Steganographia which comes from the Greek words (στεγανό-ς, γραυ-ειν), steganos literally means “covered”; and graphia means “writing”. Eventually the entire
definition is defined as covered writing (Petitcolas et al., 1999).
1.2 Statements of the problem
Over the years, numerous steganography techniques that embed secret data into cover-objects such as image, audio, video etc. have been invented and implemented. However, in the current image-based steganography technology, there are several
problems arise due to
i. Distortion produced in a stego-image after embedding a secret data.
There are certain existing schemes such as Hide and Seek 4.1 and Hide in the Picture 2.1 result in a distorted stego-image after embedding a secret data. Due to this factor, the stego-image produced is able to raise suspicion and can be clearly distinguished by an attacker. Thus, researches on alleviating the distortion problem in the stego-image need to be carried out.
ii. There is a rest