Semiconductor NAND Flash based memory technology dominates the electronic Non-Volatile storage media market. Though NAND Flash offers superior performance and reliability over conventional magnetic HDDs, yet it suffers from certain data-security vulnerabilities. Such vulnerabilities can expose sensitive information stored on the media to security risks. It is thus necessary to study in detail the fundamental reasons behind data-security vulnerabilities of NAND Flash for use in critical applications. In this paper, the problem of unreliable data-deletion/sanitization in commercial NAND Flash media is investigated along with the fundamental reasons leading to such vulnerabilities. Exhaustive software based data recovery experiments (multiple iterations) has been carried out on commercial NAND Flash storage media (8 GB and 16 GB) for different types of filesystems (NTFS and FAT) and OS specific delete/Erase instructions. 100 % data recovery is obtained for windows and linux based delete/Erase commands. Inverse effect of performance enhancement techniques like wear levelling, bad block management etc. is also observed with the help of software based recovery experiments.

中文翻译：

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基于 NAND 闪存的存储中数据删除漏洞的调查

基于半导体 NAND 闪存的存储技术主导着电子非易失性存储介质市场。尽管 NAND 闪存提供优于传统磁性 HDD 的性能和可靠性，但它存在某些数据安全漏洞。此类漏洞可能会将存储在媒体上的敏感信息暴露给安全风险。因此，有必要详细研究用于关键应用的 NAND Flash 数据安全漏洞背后的根本原因。在本文中，研究了商业 NAND 闪存介质中不可靠的数据删除/清理问题以及导致此类漏洞的根本原因。已经在商业 NAND 闪存存储介质（8 GB 和 16 GB）上针对不同类型的文件系统（NTFS 和 FAT）和操作系统特定的删除/擦除指令进行了基于软件的详尽数据恢复实验（多次迭代）。对于基于 Windows 和 linux 的删除/擦除命令，可以获得 100% 的数据恢复。在基于软件的恢复实验的帮助下，还可以观察到性能增强技术（如磨损均衡、坏块管理等）的反作用。