Secure and private communications are critical aspects of globalization, and advanced technologies will play an increasing role in development of the information society. Investigations on novel and advanced secure communications schemes will provide the potential to overcome the limitations of the conventional encryption methods. A large number of services, critical for the development of the future economic activities (e-commerce, e-document exchange and authentication, etc.) will rely on the security of the communication channels. OCCULT was directed exactly at this target: To investigate and propose new concepts on the security of the communication channels and to prove the feasibility of these concepts. Our group participated in the European IST FET project "OCCULT" and it was responsible for the system and transmission experiments. The group demonstrated for the first time the operation of a complete chaos encoded transmission system at bit rates up to 2.4 Gb/s over standard single mode fiber. The results of these activities have been published in international journals (Nature, IEEE JQE, JLT, JSTQE) as well as in international conferences (OFC 2003, ECOC 2004, ECOC2005).