“…This idea immediately motivated several researcher to use chaotic signal for secure communication purpose with the belief that it will be difficult for an intruder to decipher the transmitted message without the knowledge of the transmitting chaotic system, due to its extremely high sensitiveness to the initial conditions and parameter mismatches. As a result, a number of methods have been proposed for secure communication and cryptography [Hayes et al, 1993;Cuomo & Oppenheim, 1993;Murali & Lakshmanan, 1993a;Murali & Lakshmanan, 1993b;Kocarev & Parlitz,1995;Lakshmanan & Murali, 1996;Zhang et al, 1998;Baptista, 1998;He & Vaidya,1998;Wong et al, 2003;Kocarev et al, 2004;Bowong, 2004;Hua et al, 2005;Chee & Xu 2006] using chaotic signals. In particular, Cuomo and Oppenheim [Cuomo & Oppenheim, 1993] have suggested a very simple method for secure digital signal transmission using the property of the coupled chaotic systems that a small difference between the corresponding parameters in the drive and response systems will cause synchronization frustration in their dynamical variables.…”