本論文設計了一種加密演算法，演算法的金鑰基於渾沌系統產生。為此我們
提出了一個四維的渾沌系統，之後以相圖分析與李亞普諾夫指數以及 Random
NIST 測試對渾沌系統的特性進行驗證。經驗證後，我們以尤拉方法取得渾沌系
統的離散時間訊號。而金鑰產生器依照渾沌系統的離散時間訊號與明文檔案的特
徵值產生兩個金鑰序列。這些金鑰序列在加密演算法中分別被用於排列運算、擴
散運算對明文檔案完成加密。
接下來我們將加密演算法和無線音訊傳輸系統實現到基於FPGA的SOPC系
統之上，所使用的硬體為 Altera 的 DE10 Standard 開發版。發送端，系統會讀入
音訊檔案，然後呼叫加密演算法將圖像檔案加密，待音訊檔加密完成後將密文寫
入 SD Card，再將密文透過無線發射器傳送到傳送到另一塊開發版上，接收端系
統會呼叫加密演算法將密文解密，待密文解密完成後將明文寫入到 SD Card 上。
此外系統在讀入、接收音訊檔以及加密、解密檔案後都會將處理後的資料透過
WM7831 端口播放音訊。
最後我們透過對多個密文進行直方圖分析、相關性係數分析、差分攻擊分析
以及熵值分析，驗證加密系統的安全性。並對本論文中基於 FPGA 的 SOPC 加密
傳輸系統未來改進方向提出建議。

This thesis designs a cryptographic algorithm. The key of the algorithm is
generated based on the chaotic system. To this end, we propose a four-dimensional
chaotic system, and then verify the characteristics of the chaotic system with phase
diagram analysis, Lyapunov exponent and NIST test. After verification, we obtained
the discrete time signal of the chaotic system by the Euler method. The key generator
generates two key sequences according to the discrete time signal of the chaotic
system and the eigenvalues of the plaintext file. These key sequences are used for the
permutation operation in the encryption algorithm, and the diffusion operation
encrypts the plaintext file.
Next, we implemented the encryption algorithm and wireless audio transmission
system on the FPGA-based SOPC system. The hardware used is Altera's DE10
standard development version. At the sending end, the system reads the audio file, and
then calls the encryption algorithm to encrypt the image file. After the audio file is
encrypted, the ciphertext is written to the SD card, and then the ciphertext is
transmitted to the other through the wireless transmitter. On the version, the receiving
end, the system will call the encryption algorithm to decrypt the ciphertext, and after
the ciphertext decryption is completed, the plaintext will be written to the SD card. In
addition, the system reads, receives audio files and encrypts, and decrypts the files
and then plays the processed data through the WM7831 port.
Finally, we verify the security of the encryption system by performing histogram
analysis, correlation coefficient analysis, differential attack analysis and entropy
analysis on multiple ciphertexts. And put forward suggestions for the future
improvement direction of FPGA-based SOPC encryption transmission system in this
thesis.

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