Research On Application Of Chaotic Technology To Contemporary Secure Communication

As a phenomenon found in non-linear dynamic system, chaos is deterministic and random-like. Based upon the sensitive dependence of chaotic systems on their initial conditions, a large number of non-periodic, continuous broadband frequency spectrum, noise-like, yet deterministic and reproducible signals can be generated. So chaotic technology is very useful for secure communications. Based on applications of chaotic technology to contemporary secure communications, 'the author has performed comprehensive research and obtained the following innovative results:1. Through analyzing the dynamical properties of cellular neural networks (CNN), hyper-chaos is generated. The. author proposes a novel synchronization scheme for encrypting plain signals. Theoretical analysis and computer simulation results show it is of high security.2. Based on chaotic sequences and Rijndael block cipher algorithm, the chaotic technology and classical encryption approach, the author proposes a BCPC (Block Cipher Pseudo-chaotic) sequence and in terms of output-block feedback mode. The author has applied BCPC code to two fields. One is a frequency hopping (FH) communication system. Theoretic analysis and simulation results show BCPC sequence features ideal random performance, good hamming correlation property and wide Fll gap. Moreover, anti-jamming and anti-decipher ability of BCPC sequence is quite strong, and the sequence is also easy to be standardizted as well as suitable for flexible key management mechanism. Another application field of BCPC code is cryptology, the author has: i) developed a new Hash function; ii) hided the binary-coded images by BCPC codes; iii) developed an encrypt-decrypt software based on C++ Builder 5 platform. The author has analyzed its feasibility on security, efficiency of implementation and key management. This software can realize encrypt-decrypt files and signature-verification.3. Based on chaotic sequences and clock-control stream cipher, by combining the chaotic dynamics and classical stream cipher technology, the author has developed an SCQC (Stream Cipher Quasi-Chaotic) sequence. The SCQC sequencehas been successfully used to generate Fll-SS code, i.e. the reversal PSK. generator.4. The author has developed a chaotic digital watermarking technique featuring high robustness and security as well as strong capability of anti-jamming. This kind of watermarking is hard to be decryped by existing decryption methods.