An Algorithm for Secure Deletion in Flash Memories

Abstract

Data deletion in flash memories involves erasing the bits and making the memory free. As contents get deleted in the flash memory, time is consumed in deleting the data on the flash permanently. This paper proposes a method to make the contents of the deleted blocks in the flash memory unreliable by suitably introducing errors in the error correcting code bits of the block and randomly changing bits in each page of the block. This method saves the time to erase a block completely on deletion. The algorithm was simulated on a sample file. It gave a performance improvement of 92.88% over zero overwriting and 92.98% over block erasure methods.