隨著科技的發展，對於儲存系統上，NAND Flash Memory具有體積小、非揮發性、高抗震性、低功耗及快速儲存等優點，成為目前手機、行動電子裝置及攜帶型個人電腦的主要儲存設備。Flash Memory相較於傳統硬碟(Hard Disk Drive)來說，在資料抹除(Data Sanitization)方面有很大的不同，傳統硬碟可以針對讀寫的最小單位磁區(Sector)進行抹除的動作，而Flash Memory因為硬體上的限制，最小的抹除單位是區塊(Block)，區塊是由最小的讀寫單位頁面(Page)所組成的。其中，資料刪除一直以來都是一個重要的問題，如何確保資料刪除，無法利用軟體方式或硬體方式復原資料，在傳統硬碟上利用複寫方式讓最小單位磁區達到抹除磁性，達到抹除資料的效果，但在Flash Memory上的讀寫與抹除機制與傳統硬碟並不相同，本文將探討，在傳統硬碟上的演算法是否適用於NAND Flash-memory，並且提出相對應適合NAND Flash-Memory的演算法。

Recently, NAND flash memory has been widely used in wearable mobile devices. Data erasure is one of most important issue in Wearable Mobile Devices, the instruction of deletion from file system is not able to delete data completely in NAND flash memory, it still can use data recovery software to recover data. In the thesis, first, we will introduce NAND Flash Memory, and then we will proposes an application with various algorithm and compare each algorithm. In the end, we will conclude an algorithm which can delete data completely in NAND flash memory.

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