The Research And Design Of Information Encryption Based On Chaos Theory

Today, in the digital world, information security becomes more and more important. Since the core technique of information security is cryptology, the research suitable for various information encryption algorithms that have high efficiency and security has important actual meanings.As a phenomenon found in non-linear dynamic system, chaos is deterministic and random-like. The complexity, randomness and sensitivity to initial conditions of chaotic sequences have close relation to cryptographic properties. The security of traditional cryptology is confronted with menaces, chaos-based encryption has become a new research field of cryptology and been widely investigated recently.Firstly, we describe the definitions and characteristics of chaos from chaotic dynamics aspect, discuss how to measure chaotic systems, introduce some typical chaotic systems and study the relationship of chaos theory and cryptology. Then we analyze in detail the principle of sequence cipher and study the design of chaotic sequence cipher. Based on the typical Logistic Map, a chaotic sequence cipher is designed and simulated.Because of the weaker security and easier realization of low dimension chaotic systems and the dynamical degradation of digital chaotic systems realized in finite precision, a new pseudo-random number generator based on multiple chaotic systems is presented in this paper. It is difficult for an eavesdropper to extract information about chaotic systems for every bit of pseudo-random number generator is generated from three different chaotic orbits. Detailed theoretical analyses show that it has perfect cryptographic properties, and can be used to construct stream ciphers with high security. Then a chaotic stream cipher based on the pseudo-random number generator is designed, which has high security, low cost and easy realization proved by some experiments.However, most traditional encryption techniques are designed for textual information and they are inconvenient and inefficient for multi-medial data. It is necessary to develop techniques for multi-medial data. So the image encryption...