今日的雲端提供商（Cloud Provider）在提供服務給予使用者前，皆會與其簽訂服務階層協議（Service-Level Agreement，簡稱SLA），然而目前雲端上卻沒有提供一個可信任的方法去證明服務是否達到SLA的標準。Amazon本身有提供雲端監控服務（CloudWatch），然而此監控工具（Monitoring tools），為雲端提供商所提供，若提供商給予錯誤資訊或想規避一些服務缺失，使用者也無從防範，可稱為「球員兼做裁判」的狀況，球員自己審查自己的比賽，對使用者來說沒有信服力。
本論文為避免雲端服務商在租用虛擬機器給予使用者時，出現非使用者自主性服務中斷等狀況，我們使用證明違約（Proof of Violation，POV）技術在服務提供商及虛擬機器間建立一個可信任的演算法，並且再改良此演算法，使其證據儲存空間及稽核時間能進一步優化。

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