駭客可能攔截無線通訊中傳輸的任何資訊，故安全是無線通訊的基本要求。而身分驗證協定是確保資料通信安全的必要技術。Lin提出一種使用混沌映射法的改良公開金鑰身分認證機制，其後Islam等人指出Lin的機制之缺點，並提出一種使用擴充混沌映射法的身分驗證機制。然而，本研究發現，Islam等人所提出的機制仍有多項缺失，包括離線猜身分攻擊、使用者偽裝攻擊和伺服器偽裝攻擊等。因此，本論文提出一種身分驗證機制，可改善Islam等人提出的機制。本論文提出的機制，不僅能抵抗離線猜身分攻擊、攻擊及伺服器偽裝攻擊，同時也可降低計算成本。
Security is an essential requirement in wireless communication environments, be-cause hackers can intercept any information spread wirelessly. Therefore, an authentica-tion scheme is a necessary mechanism to ensure the security of data communications. Lin proposed a public key encryption authentication scheme using chaotic maps. After that, Islam et al. pointed out the weaknesses of Lin’s scheme and proposed an authenti-cation scheme with enhanced chaotic maps. However, in our study, we have found sev-eral weaknesses of Islam et al.’s scheme, such as it is vulnerable to off-line password guessing attack, user impersonation attack and server spoofing attack. Therefore, we propose an authentication scheme to improve Islam et al.’s scheme. In this thesis, the proposed scheme not only can counter off-line password guessing attack, user imper-sonation attack and server spoofing attack, but also can reduce the computation cost.
