A state-of-the-art survey of coverless text information hiding

Information plays a pre-eminent role in people's routine lives. It provides people with facts about abundant topics of interest. Information can be represented by a variety of communicative media such as text, video, audio, and image, out of which text is the most common medium for representing the information. In the digital era, the information can easily be imitated, exchanged and distributed from one place to another in an instant. Thus, it is incredibly essential to hide the confidential information so that it couldn’t be accessed by unauthorized means. The traditional information hiding techniques require a designated carrier to hide the secret information, which ultimately introduces some modifications in the carrier. As a result, it is quite hard for the existing traditional methods to escape from the steganalysis. In contrast to conventional information hiding techniques, the term ‘coverless information hiding’ has been coined by the researchers lately, which doesn’t require a designated carrier to conceal the secret information. Hence, the technique of coverless information hiding can efficiently resist the attacks of steganalysis. This paper presents a state-of-the-art survey of coverless text information hiding by discussing the current scope of the aforementioned technique comprehensively. The existing coverless text information hiding methods are compared and contrasted by various vital aspects such as embedding capacity, algorithm efficiency, ability to resist steganalysis, and methods’ theoretical and real-world significance. Moreover, some future aspects of coverless text information hiding are highlighted at the end.