由於使用密碼的身份驗證系統的威脅越來越大，使得透過人體特徵進行認證的生物辨識系統變得越來越重要。然而主流的辨識系統所採用的特徵，如指紋、虹膜、耳型及臉部等，容易被他人間接取得，如透過照片或是使用過的物品等，故需要一種新的生物辨識方式以提升安全性。近年來，基於體內通訊(Intra-Body Communication ; IBC)通道的生物辨識系統被認為是可以改善現行的生物辨識系統中易於被取得特徵的缺陷。由於在身體區域網路中，手臂被廣泛的討論並應用於體內裝置間通訊的媒介，使得基於手臂的體內通訊通道已被分析得十分透徹，故手臂被選為第一個應用於基於體內通訊通道的生物辨識系統的部位。然而基於手臂體內通訊通道的生物辨識系統需要額外的人員協助辨識者連接至辨識系統，可用性十分的差。除此之外，亦難以將電極貼在相同的位置上，而不同的位置會造成系統無法識別使用者，使得使用者無法認證進而存取系統。為了改善系統的可用性以及電極的定位能力，基於手掌通道的生物辨識系統被提出。此系統使用固定間距的電極進行通道量測，故使用者僅需將手置於裝置上即可進行辨識，且手掌形狀十分適合將電極進行定位。然而，手掌的體內通訊通道從未被單獨討論過，使得無法針對其特性進行系統設計，進而造成此系統準確度極差，僅能作為其他生物辨識的輔助特徵，以避免誤判。有鑑於此，在設計一個易於使用、具有高度保密性、並高度準確的辨識系統方面，針對手掌的體內通訊通道進行更全面的完整分析是關鍵的第一步。通道建模是一種常見用來分析通道特性的方式，而通道特性則是基於體內通訊通道生物辨識系統的辨識特徵，若能分析出不同人的通道特徵差異，即可針對此部分進行系統設計，以提升系統準確度。但是，不同的結構會造成不同的通道特性，而手掌的的結構交雜著肌肉與骨頭十分的複雜，若使用固定間距的電極量測不同手掌會測得不同的通道特性，使得若要對手掌進行建模需要考量電極偏移的問題，而手掌的體內通訊通道亦從未被單獨建模過。在本論文中，我們提出了一個應用於基於體內通訊的生物辨識系統，針對手掌的體內通訊通道模型。我們提出的模型特色之一是可以套用不同的手掌大小並自動修正在相同的電極間距下，結構改變造成通道的不同。同時我們設計了一個模擬平台以利使用者進行不同參數的模擬，以及設計電極的間距，進而使得設計一易於使用且保密性高的生物辨識系統。我們亦透過與一個驗證過其生理結構準確性的電磁模型進行比較，以驗證我們模型的準確度。我們的實驗結果顯示，此兩者的模擬結果趨勢相近，故我們基於手掌的體內通訊通道模型十分的準確。

Due to the increasing threats of authentication systems that use passwords, biometrics that are authenticated by users themselves have gradually gained importance. The mainstream biometric system is mainly conducted by the recognition of the fingerprints, irises, ear shapes, and faces of each person. However, these features are easy to be captured by others, so as to cheating the biometric system to obtain the access authority of the secured device. In recent years, there have been many studies using the intra-body communication (IBC) channel as a means of biometric authentication for enhancing the security. Specifically, as the arm-based IBC channel has been used in the body area network (BAN) for transmitting data between devices attached to the human body, it is a well-known channel of IBC that makes the arm lucrative to be the first part to be used in the IBC-based biometric authentication. Nevertheless, the arm-based IBC approach requires another person to help the user connect to the system, making it impractical to be realized. Moreover, it is not feasible to connect the electrode to arms at the same location every time which causes the system fail to identify users. To improve the usability of the IBC-based biometric authentication and the stability of the electrode, the palm-based IBC biometric system has been proposed by using two fixed electrode pair that user only needs to put their hand on. Nonetheless, the IBC channel of palm has never been thoroughly investigated, which heavily degrades the accuracy of the palm-based biometric authentication means and thus hinders the effectiveness and applicability. As a result, it is paramount to investigate the characteristic of palm-based IBC channel model such that a user-friendly and secured biometric authentication system can be built based upon. Since creating a channel model is a common method used to analyze the channel characteristic in wireless communication system, the IBC channel of palm can be investigated through channel modeling. However, there is no IBC channel model only modeling the palm of hand. It is necessary to create a IBC channel model based on palm. This paper proposes a parametric palm-based IBC channel model that can be adaptively calibrated with the differences of the IBC channel that is caused by the electrode offset and different palm sizes. Specifically, the proposed channel model emulates the palm-based IBC channel characteristics by only knowing the palm size and electrode configurations. Furthermore, a simulation platform is implemented that can simulate the IBC channel response of different palms under the same electrode setup. The proposed channel model is compared with the classical anatomically correct electromagnetic (EM) model. The experimental results show that the characteristics of the proposed model is very close to the EM model, verifying the accuracy of the proposed model.

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