|
Copyright Protection Using Non Linear Forward Feedback Shift Register And Error-Correction Technique
 Dr. Navin Rajpal Reader , SIT Guru Gobind Singh Indraprastha University Delhi,INDIA Phone: 23862856 (O); 27056154 (R),9811489759(mob) Email:Navin_rajpal@yahoo.com Anil Kumar Lecturer,IT Deptt Bharati Vidyapeeth College of Engg, A-4,Pacschim Vihar, Delhi-110063,INDIA. Tel 01276210841 Email: Dahiyaanil@yahoo.com Sureka Dudhani Reader,Electrical Deptt Bharati Vidyapeeth College of Engg A-4,Pacschim Vihar, Delhi-110063,INDIA. Email: Sureka65@rediffmaikl.com  Pravesh Raja Jindal IT Deptt, Bharati Vidyapeeth College of Engg, A-4,Pacschim Vihar,Delhi-110063,INDIA. Email: Pravesh_raja@yahoo.com
1. Brief Introduction
The steganography consists of techniques to allow the communication between two persons, hiding not only the contents but also the very existence of the communication in the eyes of any observer. These techniques use a second perceptible message, with meaning disjoined by the secret message. This second message works as a “Trojan horse”, and is a container of the first one. 2. Brief of a non linear forward feedback shift register? A Non-Linear feedback shift Register (NLFFSR) is a mechanism for generating binary sequences [7]. Figure 1 shows a general model of an n-bit NLFFSR. It is a Non linear forward feedback shift register with a feedback function f.  3. Brief of pseudo random binary pattern generation using nlffers NLFFSRs make extremely good pseudorandom binary pattern generators [8,9,10]. When this register is loaded with any given initial value (except 0 which will generate a pseudorandom binary pattern of all 0s). The only signal necessary for the generation of the binary pattern is a clock pulse. With each clock pulse a bit of the binary sequence is produced. A model of 4-bit LFSR is considered to demonstrate the functioning of NLFFSR with the feedback function f =1+x+x4 nonlinear feedback shift register generator. Its initial bit values are used (1111). The output sequence Zn: 111101011001000……….. Generated by NLFFSR is periodic of period 15. 4. Brief of how to error protect the data To error code the data we use first the concept of duplicating the bits and then applying concept of the redundancy bits. To enhance the performance of the error coding we duplicate each of the crypted bit eight times and then apply the Block technique to this stretched data stream, this work we do ensures that the data hidden in the image is secure even against the heavy distorting.  |