智慧型手機的銷售量年年成長，而相關的安全性議題也越來越重要。為了保護智慧型手機內的資料，目前現有的智慧型手機使用者識別機制有侵入式與非侵入式兩種。傳統的驗證機制（密碼鎖、圖形鎖）屬於侵入式識別機制。非侵入式識別機制則不需要驗證介面，而是從背景收集使用者行為進行驗證。目前已有數種研究提出非侵入式識別機制，但皆採用同一姿勢進行實驗，未考慮不同姿勢造成的影響。首先本研究對不同姿勢下收集到的行為資料分析，證實不同姿勢下的資料彼此之間有顯著差異。第二部分以應用的角度而言，若混和不同姿勢的資料建模、測試的實驗與各姿勢行為資料獨立建模、測試的實驗相比準確率沒有下降很多，則可以直接忽略姿勢影響，混和各姿勢的資料進行建模。此問題將以動態方法進行實驗並根據實驗結果告知後續研究者可以直接混和各姿勢的資料進行建模、測試。最後推薦可以避免姿勢影響且實驗效果最佳的分類器。

Smartphone sales obviously grew in this years, so the associated security issues about smartphone has become more important. In order to protect the data within the smartphone, intrusive and non-intrusive user authentication mechanisms were developed. Traditional authentication mechanisms like number lock and pattern lock are intrusive user authentication mechanism. Non-intrusive user authentication mechanism doesn’t require any user interface, but collect user’s behavior in the background and authenticate it. Several non-intrusive authentication mechanisms were proposed, but all of them collected user behavior in one fixed posture. These mechanisms didn’t take posture’s effect into consideration. First, for this study, we analyze user’s behavior data in different postures and confirm that user’s behavior data has significant differences in different postures. Second, from the view of the application, if the accuracy that use mixed posture behavior data’s model to predict isn’t significantly lower than the accuracy that separately use single posture behavior data’s model to predict, we can directly neglect posture’s effect and use mixed posture behavior data’s model to predict. This problem will be discussed by doing the experiment in dynamics-based approach and then inform the future researchers that they can use mixed posture behavior data’s model to predict according to the experiment result. Finally, we recommend the best classifier that can avoid the posture’s effect and have the best prediction accuracy.

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