ATMS資料傳輸之資訊安全研究

Abstract

ITS的目標在於促進交通安全、減少擁擠、提高機動性、增進經濟生產力、減少環境衝擊、提昇能源使用效率及帶動相關產業發展。而先進交通管理系統(Advanced Transportation Management System, ATMS)乃為ITS下之核心系統，其中最重要的乃是駕駛人所需即時交通資訊之傳輸、交通控制中心須依即時收取之資料，將最正確的訊息與決策傳給用路人與路側設施，此涉及許多技術專業如通訊、電機、資訊工程等與開發空間，且商機無限；在ATMS之資料傳輸中，乃採用NTCIP(National Transportation Communications for ITS Protocol)作為其傳輸協定，為了與現行通用之通訊協定相結合而不致有所衝突，NTCIP之堆疊(Stack)亦依循ISO-OSI(Open Systems Interconnect)之七層模型架構。 採用ISO-OSI之模型架構使得NTCIP不至於與現行通訊協定不相容，但開放式的網路環境也為NTCIP帶來許多安全性(Security)的問題，如駭客(Hacker)可在封包傳輸途中進行攔截，並對其進行竄改、偽裝、重送等攻擊，然而在實際應用上，其資料的傳輸安全性卻往往為人們所忽略。故本研究透過現行之密碼學相關技術，針對資料傳輸之確認性(Authentication)、機密性(Confidentiality)與完整性(Integrity)等對傳輸訊息進行加密保護，對於ATMS之傳輸建立ㄧ套安全機制，藉此提高ATMS之傳輸安全性。 而由於加解密對於系統亦會產生負效用，因此本研究尚進行實驗設計，以探討其封包於加密前後之傳輸時間影響，並進行統計檢定，以確認封包加密對其之影響幅度，最後會依實驗結果對於加密前後之封包於LAN之傳輸時間進行可靠度分析研究，以使得採用加密機制之交控中心人員能夠依其所需之可靠度，訂立相關傳輸時間之門檻值。

ITS aims at enhancing traffic safety, reducing congestion, increasing travel mobility, enlarging economic power and controlling efficient energy-use. Since automobile is the major mode for our travel, developing an advanced safe smart vehicle in the field of ITS is important for our society. Advanced Transportation Management System is the major sub-system of ITS. The transportation of traffic data which drivers need is the most important factor for ATMS. However, the security of data transmission has been neglected by most of people. By this reason, this project concentrates on developing a security scheme for data transmission of ATMS. The technique of cryptography would be adopted to protect the contents of data packet from masquerading, replying and tampering. How to verify the source of messages is also what we concern, message digest is a good method to implement it. Implementing the security scheme is the final objective of this research. We should concern the performance of security and efficiency because the process of encryption and decryption would consume a lot of resource of core system. How to look after both the security and efficiency of transmission is the main problem of this project. However, we consider ATMS would become more complete and secure by solving this problem.