一個兼具隱私與效率的車載隨意網路安全協定

Abstract

物聯網 (Internet of Things, IOT) 是一個很重要的研究課題與產業趨勢，而車載隨意網路 (Vehicular Ad-hoc Network, VANET) 是物聯網的核心拼圖之一，但在VANET中，個人隱私與資料安全是大多數車主所關心之議題，導致VANET普及速度相當遲緩。因此，本研究結合變色龍簽章 (Chameleon Hashing Signature)、共享金鑰 (Shared Key Scheme) 和Kerberos，提出一個能夠兼具隱私及效率的安全協定。針對隱私保護問題，本研究使用變色龍簽章及Kerberos，來減少在通訊及服務存取期間，車輛的真實身份傳遞次數，而避免隱私外洩。針對效率問題，本研究使用橢圓曲線密碼學 (Elliptic Curve Cryptography, ECC) 為基礎來設計安全機制，因此在效率上會比起傳統使用RSA演算法的機制較佳。根據安全分析，此協定除了可達到與其他相關協定相同等級的安全性，並可額外支援不可否認性。經由模擬實驗分析，本協定平均通訊花費時間可落在合理接受範圍內。同時，雖額外提供服務存取與群體通訊功能但不會增加訊息遺失率(Message Loss Rate)。

In recent years, the Internet of Things (IOT) has drawn much attention. The Vehicular Ad-hoc Network (VANET) is a key element of IOT. Because of the concerns over personal privacy and data security, the deployment of VANET is very slow. To address this issue, in this thesis, we propose a privacy and efficiency preserving security protocol. As for privacy, the proposed protocol adopts Chameleon hashing signature, shared key scheme and Kerberos to reduce the number of times of transferring the identities of vehicles so as to prevent privacy leakage. As for efficiency, the proposed protocol is based on the Elliptic Curve Cryptography (ECC) to design a security mechanism. It is more efficient than other mechanisms which are usually based on the traditional RSA algorithm. In security analysis, the proposed protocol can achieve the same security level as existing protocols and additionally support non-repudiation. Simulation results indicate the average transmission time incurred is in an acceptable range. Although the proposed protocol supports access service and group communications, it does not increase the message loss rate.