| Summary: | 碩士 === 國立臺灣科技大學 === 自動化及控制研究所 === 105 === With the rapid development of information technology, portable data storage devices, Internet and cloud services have become a part of human daily life. For the digitization of personal information, information security has become a significant issue, in which data encryption is one of the popular research object.
In this study, a parallel port transmission technique based on four-dimensional chaotic system is proposed for the security of hardware communication. Applying the Matlab to analyze the new 4D chaotic system’s properties which include 2D phase portraits, symmetry and invariance, divergence analysis, equilibrium analysis and Lyapunov exponent diagrams.
First, through the two-dimensional phase portraits, divergence analysis, equilibrium analysis and Lyapunov exponent diagram, the new four-dimensional chaotic system is simulated and confirmed that its chaotic properties can be used to generate chaotic sequences through the Euler’s method as the shuffle sequence.
In cryptography, confusion and diffusion operations are the main methods for designing the encryption algorithm. In this experiment, all the encryption operation is performed by generating chaotic sequence. In the confusion phase, the characteristic of chaotic pseudorandom sequence is used to shuffle the data content by bit-level permutation. Next, the pixel characters are also substituted by using chaotic pseudorandom number in diffusion phase. All the function for cryptosystem is implemented by Altera DE2-115 FPGA which supports the chaotic secure on parallel transmission.
In order to analyze the security of proposed encryption algorithm, a BMP color image will be encrypted and accessed through FPGA. Finally, result of the Matlab analysis, we can get the conclusion of the new 4D chaotic system is a high security and simple-design for a cryptosystem.
|
|---|
