According to this study, the researchers evaluated 12 SSDs, of those that had built in ATA and SCSI commands for wiping data – only eight of the twelve – half of the wiping routines on those eight didn't work.
The researchers suggest, instead, that disks be encrypted as soon as the initial system image is created.
They found that degaussing the drives (using magnetism to destroy the structure of the data) didn't work properly. And software wiping of individual files could not be relied upon to properly work with native routines. However, wiping the entire drive with software routines worked often, but not always.
The team provided tools they believe make file sanitation more effective. "Overall, we conclude that the increased complexity of SSDs relative to hard drives requires that SSDs provide verifiable sanitization operations," the report concluded.
This news is troubling for those in industries with highly-sensitive, confidential, or regulated industries who must ensure drive data is properly destroyed.
Colleague Mathew J. Schwartz covers more detail in his story, SSDs Prove Tough To Erase:
How can SSDs be effectively secured or disposed of, short of physically destroying them? The researchers propose encrypting all data from the start, then destroying the encryption keys and overwriting every page of data to securely wipe the SSD and block future key recovery.
Implementing such an approach requires planning. "To properly secure data and take advantage of the performance benefits that SSDs offer, you should always encrypt the entire disk and do so as soon as the operating system is installed," said Chester Wisniewski, a senior security advisor for Sophos Canada, in a blog post. Based on the researchers' findings, "securely erasing SSDs after they have been used unencrypted is very difficult, and may be impossible in some cases," he said.
For my security and technology observations throughout the day, find me on Twitter as @georgevhulme.