| Author: | Xu, Huafeng |
| Title: | Computer-generated hologram and its application |
| Advisors: | Chen, Wen (EIE) |
| Degree: | M.Sc. |
| Year: | 2021 |
| Subject: | Data encryption (Computer science) Computer networks -- Security measures Computer security Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Electronic and Information Engineering |
| Pages: | iv, 58 pages : color illustrations |
| Language: | English |
| Abstract: | The investigation of optical cryptosystems plays a significant role in information security. The fundamental conception of optical information security is to avoid inevitable attacks when image is transmitted. The original encrypted image, which cannot be visually distinguished and challenging to hack, plays an integral part in the cryptosystem. Compared to conventional optical encryption technology, the computer-generated hologram has lots of advantages, e.g., non-limited to physical project and less cost and flexibility. In order to guarantee system variety and security, there is a significant number of optical encryption systems using polarization, wavelength, especially the phase as the system security keys. However, most existing optical authentication systems are limited in processing time and correction rate, only using the iteration to get the better parameters. Thus, a simple encryption method and a novel adjust parameters method are proposed in this dissertation to settle those problems. Choosing angular spectrum propagation methodology as the primary encryption method and using particle swarm optimization or genetic algorithm to adjust the parameters, the correct rate of image decryption is improved. In addition, a novel parameters adjustment algorithm is proposed to decline time-consuming. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 5669.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.94 MB | Adobe PDF | View/Open |
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