Improving Security of Flash-Based Solid State Disks

Please enable javascript in your browser.

Samadi, Nasibeh | 2013

2030 Viewed

Type of Document: M.Sc. Thesis
Language: Farsi
Document No: 45542 (19)
University: Sharif University of Technology
Department: Computer Engineering
Advisor(s): Asadi, Hossein
Abstract:
One of the most intrinsic challenges of flash-based Solid State Drives (SSDs) is erasebefore-write limitation and the limited endurance of flash chips. Wear leveling and garbage collection are two mechanisms implemented in SSD’s controller to enhance endurance and performance. While wear leveling attempts to distribute erasures across all blocks in an even manner, it imposes a new security challenge on SSD,which leads to the presence of invalid data blocks in flash chips. Therefore, some data blocks that are logically deleted by the user are still available in flash chips and can be recovered by software or hardware recovery tools.
In this paper, a new criteria named vulnerability time is proposed to evaluate SSD security. The proposed criteria has been implemented in Disksim simulator. To address this security challenge, we have investigated the effect of SSD’s configuration parameters on the vulnerability time. The results of simulations show that wear leveling and garbage collection algorithms can affect vulnerability time by 18 times
Keywords:
Life Time ; Security ; Solid State Disk Drive ; Security Vulnerability ; Wear Leveling ; Garbage Collection