FlashFox: a secret-sharing approach to securing data deletion for Flash-based SSD

Abstract The ‘out-of-place’ update nature of Solid State Drives (SSDs) introduces a security risk. Scrubbing, a secure deletion method, mitigates this issue but negatively affects SSD endurance and requires redundant data for recovery due to page errors. Previously, the RAID-5 based scheme was used to manage redundant data. While effective for reading, it causes significant write latency due to the channel blocking issue. In response, we propose FlashFox, which integrates secret sharing and Reed-Solomon coding into SSDs, enabling the application of scrubbing within an encrypted storage environment. This innovation ensures secure deletion by cleaning up sensitive data, thereby reducing wear on SSD endurance. Furthermore, we have developed a RAID-4-based scheme for implementing FlashFox on SSDs. This scheme, by assigning specific channels to manage redundant data, successfully avoids the channel blocking issue prevalent in RAID-5. Experimental results show FlashFox reduces endurance wear by at least 15% compared to traditional scrubbing methods and writing response delay by at least 8$\times $ compared to RAID-5 based scheme.