ABSTRACT
Old CI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 7.2.4.4 Test results and comparative analysis for the New CI
PRNG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 7.2.4.5 Further investigations of two chaotic iteration schemes
based on the XORshift generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 7.3 Hash Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 7.3.2 A chaotic hash function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7.3.2.1 How to obtain E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 7.3.2.2 How to choose S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 7.3.2.3 How to construct the digest . . . . . . . . . . . . . . . . . . . . . . . . . . 144
7.3.3 Application example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Machines
7.3.4 A chaotic neural network as hash function . . . . . . . . . . . . . . . . . . . . 146
In past decades, the studies in the information hiding domain have almost exclusively been focused on robustness [2], [38]. Security has emerged in the last few years as a new interest in this domain [43], [106], [111]. Security and robustness are neighboring concepts without clearly established definitions [112]. Robustness is often considered to be mostly concerned with blind elementary attacks, whereas security is not limited to certain specific attacks. Security encompasses robustness and intentional attacks [56], [85]. The attempts to define the differences between robustness and security, to clarify the classes of attacks, and to give some consistency to the notion of security, illustrate the recent important concern to bring a rigorous theoretical framework for security in information hiding.
