A Fast Secure Deletion Strategy for High-Density Flash Memory through WOM-v Codes

High bit-density NAND flash memory, such as quadruple-level cell (QLC) flash, has been widely adopted in emerging storage systems. As voltage-based write-once-memory (WOM-v) codes reduce the erase count of a flash block before storing new data, WOM-v codes are proven feasible to extend the lifetime of high-density flash memory significantly. To ensure data security, secure deletion is widely employed in flash-based storage system.In this paper, we propose FSD, a fast secure deletion strategy for high-density flash memory that cooperates secure deletion with WOM-v codes. FSD classifies request data into secure, and unsecure data by considering data privacy. When secure data deletion command issues to the storage device, FSD cooperates unsecure data program operation to cover secure data. The results show that FSD improves the I/O performance of storage system by 70.37% over the state-of-the-art.