Flash memory secure deletion method and system based on file-level granularity

Abstract

The invention discloses a flash memory secure deletion method based on file-level granularity and belongs to the field of computer storage. According to the method, a globally unique identifier (GUID) is distributed for each file, each GUID is encapsulated to each writing request and each deletion request of the corresponding file, and meanwhile a GUID-page adjacency list is constructed and used for recording invalid physical pages corresponding to each file in real time; and when a user deletes a certain file, equipment can find all the invalid physical pages and all valid physical pages corresponding to the file through a deletion command, and then a physical page overwriting technology is used for overwriting all the physical pages of the file to achieve the purpose of deleting the file securely. The invention furthermore discloses a flash memory secure deletion system based on file-level granularity. Through the technical scheme, the problem that a single file cannot be deleted efficiently and securely through an existing solid-state disk based on a flash memory medium is solved, and influences of secure deletion on read-write performance are reduced on the basis of securely deleting a single file through the solid-state disk.

Description

technical field [0001] The invention belongs to the field of computer storage, and more specifically relates to a method and system for securely deleting flash memory based on file-level granularity. Background technique [0002] With the development of data recovery technology, it is difficult for the current computer system to completely delete files. By recovering and processing the remaining data on the storage medium, attackers can steal the deleted confidential information, which has become an important hidden danger to the information security of the storage system. A survey report in 2016 found that from more than 200 second-hand hard drives (93% were mechanical hard drives, and the rest were SSDs), it was found that more than 78% of second-hand hard drives had residual data, and 67% of them could recover personal secrets information, 11% of hard drives contain sensitive company data. In addition, the survey shows that 36% of the hard disks contain residual data, th...

AI Technical Summary

Problems solved by technology

[0011] Aiming at the above defects or improvement needs of the prior art, the present invention provides a method and system for securely deleting flash memory based on file-level granularity, the purpose of which is to transfer files to the bottom layer by assigning a GUID number to each file information, so that the device can grasp the storage location of the file data block and record the invalid physical pages generated by each file in real time; when the user deletes a file, the device can find all invalid physical pages and all valid physical pages corresponding to the file through the delete command , and then use the physical page overwriting method to overwrite all the physical pages of the file to achieve the purpose of securely deleting the file, thereby solving the technical problems of low efficiency and large delay in the existing flash memory secure deletion technology

Images