  NAND flash memory-based IoT devices inherently suffer from data retention
issues. In IoT security, these retention issues are significant and require a
robust solution for secure deletion. Secure deletion methods can be categorized
into off-chip and on-chip schemes. Off-chip secure deletion schemes, based on
block-level erasure operations, are unable to perform real-time trim
operations. Consequently, they are vulnerable to hacking threats. On the other
hand, on-chip secure deletion schemes enable real-time trim operations by
performing deletion on a page-by-page basis. However, the on-chip scheme
introduces a challenge of program disturbance for neighboring page data. The
proposed on-chip deletion scheme tackles this problem by utilizing ECC code
modulation through a partial program operation. This approach significantly
reduces the program disturbance issue associated with neighboring page data.
Moreover, the proposed code modulation secure deletion scheme allows for
real-time verification of the deletion of original data.
