SSDs Harder to Securely Purge of Data Than HDDs eWeek (02/18/11) Fahmida Y. Rashid
as it appeared in the February 23, 2010 edition of ACM TechNews.
University of California researchers have found that current disk sanitization techniques do not work on solid state drives (SSDs) because the technology's internal architecture is different than that of a hard disk drive. Sanitized is defined as erasing all or part of the storage device in such a way that the contained data was difficult or impossible to recover, according to the paper. "Reliable SSD sanitization requires built-in, verifiable sanitize operations," the researchers say. Although modern manufacturers implement standard sanitization techniques with most of their drives, the researchers found that many of the implementations were flawed. The researchers tested two standard commands, ERASE UNIT and ERASE UNIT ENH. After seven ERASE UNIT tests, the researchers found that just four out of seven drives executed it properly. "Standardized commands should work correctly almost indefinitely," the researchers say. Although current software applications for deleting the entire drive work a majority of the time, the researchers found that none of the available software techniques for securely removing individual files was effective on flash-based SSDs.
