Topological study and Lyapunov exponent of a secure steganographic scheme

CIS2 is a steganographic scheme proposed formerly, belonging into the small category of algorithms being both stego and topologically secure. Due to its stego-security, this scheme is able to face attacks that take place into the “watermark only attack” framework. Its topological security reinforce its capability to face threats in other frameworks as “known message attack” or “known original attack”, in the Simmons´ prisoner problem. In this research work, the study of topological properties of CIS2 is enlarged by describing this scheme as iterations over the real line, and investigating other security properties of topological nature as the Lyapunov exponent, that have been reported as important in the field of information hiding security. Results show that this scheme is able to withdraw a malicious attacker in the “estimated original attack” context too.