隨著網路的快速發展，資料量的負荷日益增大，人們開始追求更靈活、高速的網路服務，但也成為竊聽者攻擊的主要目標。由於光纖通信具有廣大的頻寬，可以乘載更多的訊息，所以成為近年網路通訊的重要技術之一，也因此光纖通訊的安全性得到了更多學者的關注。
而OCDMA同時具有較靈活的架構且較高的隱密性，所以有許多作者提出基於分碼多工技術的研究來提升網路的安全性，但仍不足以保障系統安全，甚至降低傳輸的速度。因此本篇提出一個使用AWG (Arrayed-Waveguide Grating)編碼器、SLM (Spatial-Light Modulator)濾波器的OCDMA系統且採用混沌序列作為密鑰，透過映射演算法使混沌序列控制系統架構讓資料使用不同的載波傳送，來產生動態變異碼的效果；接收端則利用密鑰同樣地控制系統架構來還原變異碼。本研究的架構可以大幅提升原先系統的完整性，除此之外，使用這樣的架構竊聽者在不知道密鑰的情況下無法正確的破解資訊。
本篇論文將會分兩個部分分析，第一是使用NIST隨機度分析對視為密鑰的混沌序列進行隨機度分析，透過隨機的序列使竊聽者較不易猜中密鑰；第二是針對竊聽者的竊聽行為和系統的變碼速度進行安全度模擬分析。

With the rapid development of the Internet and increasing the amount of data load, people began to need a more flexible, high-speed Internet service. However, the Internet also becomes a major target for eavesdroppers. Since the optical fiber communication has a broad bandwidth, it can take the more load capacity, so network communication became an important technology in recent years. Therefore, the security of optical communication network has attracted more attention to the researchers.
Optical Code-Division Multiple-Access (OCDMA) network possesses flexible architecture and high privacy, and there were many research proposal based on such code-division multiplexing technologies to improve network security. Nevertheless, the research results are still not good enough to secure the system, or even reduce the speed of transmission. Therefore, this thesis proposed an OCDMA system with AWG (Arrayed-Waveguide Grating) encoder, SLM (Spatial-Light Modulator) filter and chaotic sequence. Through the mapping algorithm, chaotic sequence controls system to make the user transmit data with different carriers to achieve the dynamic address code; receiver uses the same algorithm to restore the data.
The analyses of this thesis include two parts. The first part is to use the NIST to analyze the chaotic sequence that is taken as a key. The eavesdroppers will have difficulty to guess the key because of its randomness. The second part is to simulate the network security of being eavesdropped.

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