VANET本身為變化快速的網路架構，必須考量到駕駛者、車速與交通狀況，其中資訊與資訊間傳輸的保密性、完整性、合法性與效率性是相當重要之議題。由於VANET在空氣中傳輸訊息，無防火牆之遮蔽，故資料容易被駭客入侵，竊取與更改，因此在傳輸介面需要有優異的加密機制，以確保資料的安全性及正確性。但現有加解密機制應用於VANET仍未能解決安全性的問題。其中非對稱性金鑰加密系統，安全性較佳，但加解密時間過長，在車輛高速行駛間的傳輸，容易造成傳輸失敗，影響通訊品質；而對稱性加解密機制，加解密時間較短，資料傳輸快，但保密性較差，容易受駭客入侵，竄改資料。

因此，本論文提出一個改良方法，結合RSA加密系統與Oblivious Transfer (ROT)，建構n選t模糊傳輸架構進行模擬實驗，結果顯示ROT加密系統可提升加解密運算速度，且在安全性方面，對於攻擊的偵測率較RSA與DES方式高，在資料傳送時，更能抵擋異常行為攻擊、偽造訊息攻擊和中間人攻擊，因此達到較高的安全性與傳輸效率。

VANET, a rapid networking system, includes the elements of driver, speed, and traffic. When using VANET for information transmission, important issues such as privacy, integrality, legitimacy, and efficiency must be considered. Because VANET transmits information wirelessly, without the protection of a firewall, it is easy for the system to be attacked by hackers who may steal or change information. Consequently the transmitting interfaces need an excellent mechanism of encryption, which can guarantee security of the materials and exactness. At the present time VANET utilizes the asymmetrical golden key encrypt system. The security of this system is relatively good, but the decipher time is too great. Because transmissions occur in a high-speed interface, lengthy decipher times might negatively influence the quality of the transmission and sometimes lead to system failure. Another system, the symmetrical golden key encrypt system, has a short decipher time and rapid transmission speed, but privacy is relatively poor, and the system is easily invaded by hackers.

Due to the disadvantages in both the asymmetrical golden key encrypt system and the symmetrical golden key encrypt system , the present study proposed a method to improve the security and efficiency of the encryption used with VANET. In this study , a method combining the RSA encryption system and Oblivious Transfer ( ROT ) was used to construct an n to t oblivious transfer structure to simulate and analyze security and efficiency. Results revealed that the ROT encryption system can increase the pace of decipher operations, and promote network efficiency. In regards to security , the detection rate was increased and unusual-behavior-attacks , forge -message-attacks, and man-in-middle-attacks were reduced leading to increased system security.

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