This paper describes the security weakness of a recently proposed secure communication method based on parameter modulation of a chaotic system and adaptive observer-based synchronization scheme. We show that the security is compromised even without precise knowledge of the chaotic system used.
@article{arxiv.nlin/0311041,
title = {Breaking parameter modulated chaotic secure communication system},
author = {G. Alvarez and F. Montoya and M. Romera and G. Pastor},
journal= {arXiv preprint arXiv:nlin/0311041},
year = {2007}
}