Breaking projective chaos synchronization secure communication using   filtering and generalized synchronization
  This paper describes the security weaknesses of a recently proposed secure communication method based on chaotic masking using projective synchronization of two chaotic systems. We show that the system is insecure and how to break it in two different ways, by high-pass filtering and by generalized synchronization. 
Gonzalo Alvarez, Shujun Li, F. Montoya, M. Romera, and G. Pastor