Global sharing information is getting an increasing popularity. Most people have at least one e-mail address and have already joined a social networking site where they can share their personal data or send messages to each other. Although the terms and conditions of these sites state that they defend the privacy of the users, it is a good idea to defend ourselves from potential abuses. This thesis is to document and analyse various steganography methods that can be used in a web-based environment as the corresponding algorithms are able to hide the fact of message sending.
The study starts with a historical overview of some of the most well-known steganographic approaches with presenting the main features of the methods. Different algorithms for information hiding are presented along with a possible classification of them. Finally, the performance of these methods is evaluated.
Each presented algorithm is classified into one of three different groups. The first group contains text-based and character modifying algorithms which we analyze based on their throughput and detectability. These algorithms are hiding information by modifying or replacing the characters in a text.
The second group consists of order-based algorithms which use the order of entities in a cover media in order to hide information. After presenting the theory of these algorithms, we demonstrate their
capacity, pros and cons through the evaluation of two use cases.
As the third group on its own, a small proof-of-concept utility called StegoWeb is presented. This method utilizes URL shortener services to hide information. We demonstrate the advantages of using URL shorteners to increase the capacity of steganographic algorithms and show an algorithm which uses exclusively URL shorteners.